Richard Popp
Professor of Medicine (Cardiovascular Medicine), Emeritus
Medicine - Cardiovascular Medicine
Bio
Richard Popp is Professor of Medicine (Emeritus 2005) at Stanford University. Dr. Popp is a clinical Cardiologist who focused his research on development of all forms of ultrasound with more than 300 scientific publications. Dr. Popp was Senior Associate Dean for Academic Affairs at Stanford from 1995-2000. He continues to teach in the Stanford Biodesign Innovation Program. He was Chair the Conflict of Interest Committee at the Medical School from 2000 to 2018. Dr. Popp was President of the American College of Cardiology, the American Society of Echocardiography and the Association of University Cardiologists. He is the previous Chairman of the American Board of Internal Medicine’s Cardiovascular Diseases Subspecialty Board. He has received several special recognitions including The Rambam Award in Israel in 2012, the Gold Medal of the European Society of Cardiology in 2016 and the Albion Walter Hewlett Award of Stanford University in 2017.
Dr. Popp was an H-P fellow and Principal Medical Consultant to Hewlett-Packard Laboratories and Agilent Labs for many years. He was an advisor and consultant to Acuson, ATL, H-P Medical Ultrasound Division and Varian.
He was a member of The Angels’ Forum from 1995 to 2001 and a Venture Partner at Advanced Technology Ventures from 2005 to 2012. He was on the Board of Sensant until its sale to Siemens and Ardian, Inc. until its sale to Medtronic, Inc. He is an Advisor to Lightstone Ventures. He is a Founder and past Chairman of the Board of Hospi Corporation. He is currently a Board member of Tangible Science. He Chairs the Medical Advisory Board for eXo Imaging and is Medical Advisor to Arterys, Vynca, and several start-ups from the Stanford Biodesign Program.
Academic Appointments
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Professor Emeritus-Hourly, Medicine - Cardiovascular Medicine
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Member, Bio-X
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Member, Cardiovascular Institute
Administrative Appointments
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Senior Associate Dean for Academic Affairs, School of Medicine (1995 - 2000)
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Head, Section on Ethics and Policy, Stanford Byers Center for Biodesign (2000 - Present)
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Chair, School of Medicine Conflict of Interest Committee (2001 - 2018)
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Faculty Mentor, Stanford Biodesign (2001 - Present)
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Faculty Mentor, Clinical Excellence Research Center, Stanford University (2012 - 2016)
Honors & Awards
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Doctorate, Honorus Causa, University of Lisbon, Portugal (1996)
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Richard L. Popp Master Teacher Award, American Society of Echocardiography (2001)
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Rambam Award, Rambam Medical Center, Haifa ,Israel (2012)
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Lifetime Honorary Medical Staff Appointment, Stanford Hospital and Clinics (2013)
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Gold Medal, European Society of Cardiology (2015)
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Albion Walter Hewlett Award, Stanford University School of Medicine (2017)
Professional Education
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M.D., Johns Hopkins School of Medicine, Medicine (1964)
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AB, Johns Hopkins University, Biological Sciences (1960)
Current Research and Scholarly Interests
Academic-Industrial relations; Ethics of invention.
All Publications
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Outcomes from a Postgraduate Biomedical Technology Innovation Training Program: The First 12 Years of Stanford Biodesign
ANNALS OF BIOMEDICAL ENGINEERING
2013; 41 (9): 1803-1810
Abstract
The Stanford Biodesign Program began in 2001 with a mission of helping to train leaders in biomedical technology innovation. A key feature of the program is a full-time postgraduate fellowship where multidisciplinary teams undergo a process of sourcing clinical needs, inventing solutions and planning for implementation of a business strategy. The program places a priority on needs identification, a formal process of selecting, researching and characterizing needs before beginning the process of inventing. Fellows and students from the program have gone on to careers that emphasize technology innovation across industry and academia. Biodesign trainees have started 26 companies within the program that have raised over $200 million and led to the creation of over 500 new jobs. More importantly, although most of these technologies are still at a very early stage, several projects have received regulatory approval and so far more than 150,000 patients have been treated by technologies invented by our trainees. This paper reviews the initial outcomes of the program and discusses lessons learned and future directions in terms of training priorities.
View details for DOI 10.1007/s10439-013-0761-2
View details for Web of Science ID 000323736800002
View details for PubMedID 23404074
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Assessment of left ventricular function by echocardiography: A technique in evolution
JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY
2008; 21 (1): 14-21
Abstract
One of the earliest applications of clinical echocardiography was the evaluation of left ventricular (LV) size and function. The accuracy of the determination of global and regional LV function with echocardiography has improved as the technology has matured. The following paper discusses the advances in LV function assessment starting with Inge Edler's original A-mode and M-mode observation moving through two dimensional echocardiographic methods to new three dimensional echocardiographic assessment and even new Doppler and speckle myocardial methods. During the evolution of ultrasonic assessment of LV function, each new method has overcome limitations of previous ones, resulting in better appreciation of the LV geometry and volume and improved accuracy and reproducibility for quantitation. As discussed in this report, many of the echocardiographic methods used today to assess LV systolic function were envisioned by Harvey Feigenbaum more than 25 years ago. The future will undoubtedly see a new method of clinical cardiology care but with continued evolution, echocardiographic quantitation of LV function should remain a vital part of patient care.
View details for DOI 10.1016/j.echo.2007.11.007
View details for Web of Science ID 000252359000004
View details for PubMedID 18165124
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Comparison of three-dimensional echocardiography to two-dimensional echocardiography and fluoroscopy for monitoring of endomyocardial biopsy
AMERICAN JOURNAL OF CARDIOLOGY
2007; 99 (6): 864-866
Abstract
Real-time 3-dimensional echocardiography (RT3DE) offers the rapid acquisition of quantitative and qualitative anatomic data without the use of geometric assumptions. This study was designed to test the feasibility and potential superiority of RT3DE versus 2-dimensional echocardiography (2DE) and standard fluoroscopy for monitoring endomyocardial biopsies (EMBs). Thirty-eight consecutive EMBs performed under fluoroscopic guidance in 26 patients were monitored using 2DE and RT3DE alternately. Two reviewers scored each biopsy pass for visualization of the tip of the bioptome and location of the actual biopsy. Overall image quality was noted as good or poor, and the effect of image quality on tip localization was analyzed. A total of 243 biopsy attempts were made during 38 EMBs. The location of the biopsy was determined in 74% of the biopsies monitored with RT3DE, whereas 2DE demonstrated the location with certainty in only 43% of the biopsies (p <0.0001). On a procedure-by-procedure comparison, RT3DE was found to show the bioptome tip better in 23 of 38 biopsies, compared with 1 of 38 for 2DE (p = 0.001). In 14 of 38 EMBs, neither method was clearly better. In conclusion, RT3DE improves the ability to see the location of the bioptome during EMB compared with 2DE and fluoroscopy.
View details for DOI 10.1016/j.amjcard.2006.10.050
View details for Web of Science ID 000245289200027
View details for PubMedID 17350384
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An outline for public registration of clinical trials evaluating medical devices
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2006; 47 (8): 1518-1521
Abstract
Public registration of clinical trials is fundamentally important to the integrity of the medical device development process. In addition to fulfilling obligations to those study volunteers, a complete record of trial results provides the general public, clinical community, and medical device manufacturers with a more accurate understanding as to how a specific therapeutic should be used. Although the issues associated with public disclosure of clinical trials are similar to the pharmaceutical industries, the iterative nature of device development introduces differences in what type of information needs to be disclosed during development and commercialization. The Second Dartmouth Device Development Symposium (3D2) held in October 2004 brought together thought leaders representing many of the stakeholders associated with medical device development. This consensus document arising from the proceedings of the 3D2 is offered to provide background to these issues and recommend pathways to implementation of device trial registration.
View details for DOI 10.1016/j.jacc.2005.09.079
View details for Web of Science ID 000236819000002
View details for PubMedID 16630985
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Innovation, journal reviewers, and journal editors - The game is worth the candle
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2005; 46 (7): 1360-1361
View details for DOI 10.1016/j.jacc.2005.04.001
View details for Web of Science ID 000232315900024
View details for PubMedID 16198856
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Conflict of interest for the physician-inventor using a device in human subjects
AMERICAN HEART JOURNAL
2005; 149 (1): 1-3
View details for DOI 10.1016/j.ahj.2004.06.005
View details for Web of Science ID 000226387000001
View details for PubMedID 15660027
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The role of the American College of Cardiology in promoting and maintaining the delivery of quality cardiovascular care in the future
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2000; 35 (5): 99B-101B
View details for Web of Science ID 000086316700019
View details for PubMedID 10757375
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The role of the American College of Cardiology in promoting and maintaining the delivery of quality cardiovascular care in the future
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
2000; 35 (4): 1100-1102
View details for Web of Science ID 000085917200035
View details for PubMedID 10732914
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Stress echocardiography results in context
EUROPEAN HEART JOURNAL
1999; 20 (20): 1450-1451
View details for Web of Science ID 000082752800006
View details for PubMedID 10610323
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President's page: A time for celebration
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1998; 31 (4): 890-891
View details for Web of Science ID 000072623400025
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President's page: Looking back ... looking forward
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1998; 31 (2): 483-484
View details for Web of Science ID 000071796900035
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President's page: ACC's strategic plan - A road map for the future
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1998; 31 (1): 238-239
View details for Web of Science ID 000071230700038
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Recommendations for training in performance and interpretation of stress echocardiography
JOURNAL OF THE AMERICAN SOCIETY OF ECHOCARDIOGRAPHY
1998; 11 (1): 95-96
Abstract
Stress echocardiography has emerged as a clinically useful procedure in the management of patients with ischemic heart disease and other conditions. However, the accuracy of this test relies on the ability of those who carry out the technical aspects of the test and depends critically on proper interpretation of the images. Appreciation of wall motion abnormalities is generally acknowledged as one of the most difficult skills to master in echocardiography. There is consensus that this is also one of the most difficult skills to teach. Appreciating stress-induced changes in wall motion, which sometimes are subtle, requires a significant commitment to initial training in this skill and its maintenance. This document provides recommendations for physician training in stress echocardiography.
View details for Web of Science ID 000071772900020
View details for PubMedID 9487481
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Doppler evaluation of left ventricular filling in congestive heart failure
EUROPEAN HEART JOURNAL
1997; 18 (10): 1548-1556
View details for Web of Science ID A1997XZ39100009
View details for PubMedID 9347265
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Task force 3: Guidelines for credentialling practicing physicians
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1997; 29 (6): 1148-1162
View details for Web of Science ID A1997WW57700004
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President's page: First, do no harm
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1997; 29 (6): 1405-1406
View details for Web of Science ID A1997WW57700039
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28th Bethesda Conference. Task Force 3: Guidelines for credentialling practicing physicians.
Journal of the American College of Cardiology
1997; 29 (6): 1148-1162
View details for PubMedID 9137208
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A three-dimensional perspective
EUROPEAN HEART JOURNAL
1996; 17 (10): 1456-1458
View details for Web of Science ID A1996VL04100003
View details for PubMedID 8909895
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Coronary artery intimal thickening in the transplanted heart - An in vivo intracoronary ultrasound study of immunologic and metabolic risk factors
TRANSPLANTATION
1996; 61 (1): 46-53
Abstract
This study examined the hypothesis that immunologic factors are the major correlates of coronary artery intimal thickening and luminal stenosis. The study population included 116 adult heart transplant recipients with a mean age of 44.7 +/- 12.0 years (89 men and 27 women) undergoing annual coronary angiography and intracoronary ultrasound 3.4 +/- 2.7 (range, 1.0-14.6) years after transplantation. Mean intimal thickness was obtained from several distinct sites along the left anterior descending and/or left circumflex coronary artery by intracoronary ultrasound. Coronary artery stenosis defined by angiography was classified as mild (< 30% luminal stenosis), moderate (> or = 30-70% luminal stenosis), or severe (> 70% luminal stenosis or diffuse pruning of distal vessels). Prevalence of any transplant coronary artery disease (TxCAD) was 85% by intracoronary ultrasound and 15% by angiography. By multiple regression analysis, only average fasting plasma triglyceride level (P < 0.006) and average weight (P < 0.007) were significantly correlated with severity of intimal thickening (R = 0.54, P < 0.0001). Donor age (P < 0.006) and average fasting plasma triglyceride level (P < 0.009) were significantly correlated with stenosis by angiography. Correlation of multiple immunologic and metabolic factors with intimal thickness by univariate analysis suggests a multifactorial etiology for TxCAD. Among the multiple univariate correlates of TxCAD, higher fasting plasma triglyceride levels and body weight are the only independent correlates of TxCAD. The absence of acute rejection as an independent predictor of intimal thickening suggests that mechanisms beyond those mediating typical cellular rejection should be targeted for advancing our understanding of Tx-CAD.
View details for Web of Science ID A1996TQ20100011
View details for PubMedID 8560573
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TASK-FORCE-2 - ACADEMIC HEALTH CENTERS
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1994; 24 (2): 290-295
View details for Web of Science ID A1994PH37600003
View details for PubMedID 8034860
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ASSIGNMENT OF PATIENTS INTO THE CLASSIFICATION OF CARDIOMYOPATHIES
CIRCULATION
1992; 86 (5): 1622-1633
Abstract
The original classifications of the cardiomyopathies based on anatomic criteria from radiographic and necropsy studies, as well as hemodynamic criteria from clinical and catheterization data, have been supplemented in recent years by information from noninvasive techniques. Echocardiography, radionuclide methods, and ambulatory ECG, in particular, have facilitated the ethical screening of family members and those less symptomatic than patients on whom the original classification was based. These powerful methods show a broad spectrum of anatomy and ventricular physiology along the natural history of and within the traditional categories of the cardiomyopathies. They also provide data on the effect of ventricular loading conditions affecting a range of diastolic filling patterns. This review has attempted to point out the areas of overlap among and/or controversy about the categories that have led us to a feeling of frustration when trying to neatly classify individual patients. The addition of filling patterns from Doppler echocardiography and nuclear angiography to the standard methods has been reviewed and hopefully will lend more perspective to the range of physiology seen in these conditions. The categories of cardiomyopathy should not be seen as excluding patients with the newly recognized variations in anatomy and ventricular filling patterns. Rather, the classification provides a framework on which to build and expand our understanding of these important conditions.
View details for Web of Science ID A1992JW98100033
View details for PubMedID 1423973
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INTRAVASCULAR ULTRASOUND IMAGING OF CORONARY-ARTERIES - IS 3 LAYERS THE NORM
CIRCULATION
1992; 86 (1): 154-158
Abstract
The purpose of this study was to evaluate the significance of the three-layered appearance of coronary arteries in adolescence and adults from intravascular ultrasound scans and to correlate these observations with histopathology.Sixteen intact hearts were excised at autopsy from patients with no clinical history of coronary artery disease. The patients' ages ranged from 13 to 55 years. A 30-MHz ultrasound imaging catheter was used to obtain images throughout the epicardial coronary vasculature. A total of 72 image cross sections was marked by epivascular sutures, and the corresponding histological sections were examined. Ultrasound images were classified into two groups: images exhibiting three-layered appearance and images without distinct layering. Histological analysis revealed a significantly greater degree of intimal thickening in segments with three layers (243 +/- 105 microns) than in nonlayered segments (112 +/- 55 microns). Discriminant analysis of these data predicted the threshold between the two groups to be 178 microns. Measurements of medial thickness were not different between these two groups (235 +/- 61 versus 210 +/- 76 microns). In the nonlayered group, the average patient age was 27.1 +/- 8.5 years, whereas in the three-layered groups, the average age was 42.8 +/- 9.8 years.The intracoronary ultrasound image appearance of young, morphologically normal coronary artery walls is homogeneous without layering. A three-layered appearance suggests the presence of at least 178 microns of intimal thickening and is seen more frequently with advancing age.
View details for Web of Science ID A1992JC45700018
View details for PubMedID 1617768
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CONTRIBUTORS TO CHARACTERISTIC MITRAL FLOW VELOCITY PATTERN IN CONGESTIVE-HEART-FAILURE - FROM CLINICAL OBSERVATIONS BACK TO EXPERIMENTAL VALIDATIONS
SYMP ON CLINICAL EVALUATION OF CARDIAC PERFORMANCE, AT THE 55TH ANNUAL SCIENTIFIC SESSION OF THE JAPANESE CIRCULATION SOC
BLACKWELL PUBLISHING ASIA. 1992: 740–49
Abstract
Mitral flow velocity pattern in patients with left ventricular (LV) diastolic dysfunction usually includes decreased peak early diastolic filling velocity (E), slowed deceleration of the early diastolic filling wave and increased peak filling velocity at atrial contraction (A). However, the abnormal mitral flow velocity pattern can be normalized in the presence of concomitant congestive heart failure. In such cases E can be equal to or even higher than normal, its deceleration is normal or faster than normal value, and A can be normal or lower than normal value. Clinical observations in patients with severe heart failure showed that the mitral flow velocity pattern changes with vasodilating therapy, reflecting the changes in the left atrial (LA) to LV pressure difference rather than those in the absolute LA pressure or LV pressure alone. This was validated in the canine study in which levels of LV dysfunction were made by the injection of microspheres into the left coronary artery to study the interrelation among the mitral flow velocity pattern and LA and LV pressures. In this experiment, the changes in the mitral flow velocity pattern could not be explained by the changes in LA or LV pressure alone but was better explained by the changes in the LA to LV pressure difference. Not only LA-LV crossover pressure but also LA compliance seem to be important as determinants of LA pressure level in diastole. In addition to LV relaxation rate, incompleteness of relaxation, elastic recoil and LV passive elastic properties, extracardiac constraint is also considered to be an important determinant of the level of the LV diastolic pressure and hence of the mitral flow velocity pattern at least in the presence of congestive heart failure. Thus, mitral flow velocity pattern is determined by the interaction of LA and LV pressures, both of which are affected by chamber properties as well as loading conditions.
View details for Web of Science ID A1992JF83200016
View details for PubMedID 1495168
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TISSUE SIGNATURE - DISCUSSION-V
AMERICAN JOURNAL OF CARDIOLOGY
1992; 69 (20): H117-H120
View details for Web of Science ID A1992HZ51700017
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Guidelines for physician training in transesophageal echocardiography: recommendations of the American Society of Echocardiography Committee for Physician Training in Echocardiography.
Journal of the American Society of Echocardiography
1992; 5 (2): 187-194
View details for PubMedID 1571176
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CLINICAL COMPETENCE IN EXERCISE TESTING - A STATEMENT FOR PHYSICIANS FROM THE ACP/ACC/AHA TASK-FORCE ON CLINICAL PRIVILEGES IN CARDIOLOGY
CIRCULATION
1990; 82 (5): 1884-1888
View details for Web of Science ID A1990EG88600044
View details for PubMedID 2225392
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CLINICAL COMPETENCE IN ADULT ECHOCARDIOGRAPHY - A STATEMENT FOR PHYSICIANS FROM THE ACP ACC AHA TASK-FORCE ON CLINICAL PRIVILEGES IN CARDIOLOGY
CIRCULATION
1990; 81 (6): 2032-2035
View details for Web of Science ID A1990DH02100044
View details for PubMedID 2344693
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Echocardiographic and Doppler studies in hypertrophic cardiomyopathy.
Cardiology clinics
1990; 8 (2): 217-232
Abstract
This article discusses the central role of cardiac ultrasonography-- two dimensional echocardiography, Doppler echocardiography, continuous-wave Doppler, pulsed-wave Doppler--in the clinical assessment and management of patients with hypertrophic cardiomyopathy.
View details for PubMedID 2189558
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MILDLY DILATED CONGESTIVE CARDIOMYOPATHY - USE OF PROSPECTIVE DIAGNOSTIC-CRITERIA AND DESCRIPTION OF THE CLINICAL COURSE WITHOUT HEART-TRANSPLANTATION
CIRCULATION
1990; 81 (2): 506-517
Abstract
Prognosis in classically described dilated congestive cardiomyopathy has been reported to be related to ventricular size. Mildly dilated congestive cardiomyopathy (MDCM) has been defined as end-stage heart failure of unknown etiology (New York Heart Association class IV, left ventricular ejection fraction less than 30%), occurring with neither typical hemodynamic signs of restrictive myopathy nor significant ventricular dilatation (less than 15% above normal range). The present study includes follow-up in 12 nontransplant patients. In the first 4 months after diagnosis, two patients improved and are living, and two showed cardiac dilation and clinical deterioration and died. Six of the remaining eight with persistent MDCM died (four with intractable heart failure and two, sudden deaths) without change in ventricular size before death, despite medical therapy over 20 +/- 8 months. Eight comparable transplanted patients with persistent MDCM demonstrated improved total survival by life table analysis (p less than 0.05). A family history of congestive cardiomyopathy was found in nine of 16 patients (56%) with persistent MDCM. Nontransplant patients were older (p less than 0.02), but other findings were similar in the two groups. Endomyocardial biopsies available in 14 of 16 cases showed little or no myofibrillar loss in spite of severe hemodynamic impairment. The degree of myofibrillar loss did not correlate with hemodynamic parameters but showed good correlation with left ventricular size, that is, five of six patients with no myofibrillar loss had normal ventricular size, whereas all eight patients with mild myofibrillar loss had mild cardiomegaly (p less than 0.002). Our current experience suggests a somewhat variable but negative prognosis after prospective diagnosis of MDCM, with poor survival in patients with persistence of the original diagnostic features during follow-up. Preservation of heart size in MDCM is probably related to lack of significant myofibrillar loss. Thus, irrespective of heart size or myofibrillar preservation on biopsy, heart transplantation should be strongly considered in MDCM if signs of severe cardiac dysfunction persist despite therapy.
View details for Web of Science ID A1990CM83600012
View details for PubMedID 2297858
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Flow velocity acceleration in the left ventricle: a useful Doppler echocardiographic sign of hemodynamically significant mitral regurgitation.
Journal of the American Society of Echocardiography
1990; 3 (1): 35-45
Abstract
Doppler echocardiography is a sensitive method to detect mitral regurgitation in patients with both native and prosthetic valves. However, estimates of the amount of mitral regurgitation remain semiquantitative, and even severe mitral regurgitation may be underestimated in the presence of markedly eccentric regurgitant jets or acoustic shadowing of the left atrium by mitral or aortic prostheses. This report describes the Doppler findings in 10 patients with severe native valve mitral regurgitation (angiographic grade III or IV) and in 15 patients with severe bioprosthetic mitral regurgitation that required valve replacement. An increase in peak mitral flow velocity above normal values was seen in eight of 10 patients with severe native valve mitral regurgitation (greater than or equal to 130 cm per second) and 11 of 15 patients with severe prosthetic valve mitral regurgitation (greater than or equal to 210 cm per second). One of 10 patients with a native valve and four of 15 patients with a bioprosthetic valve appeared to have only a localized left atrial systolic flow disturbance, incorrectly suggesting that the mitral regurgitation was mild. However, in all patients with severe mitral regurgitation, a low velocity (less than 100 cm per second) flow signal could be recorded in the left ventricle that was directed toward the mitral valve in systole. This flow signal showed a gradual increase in velocity as the sample volume was moved toward the mitral valve, with an abrupt further increase on entry into the left atrium. This signal was continuous with antegrade mitral flow and had the same orientation as mitral regurgitation recorded by continuous wave technique from the apex. A similar flow signal was not recorded in the left ventricle of any individual in a control group of 30 patients who had no mitral regurgitation or who had angiographic grade I or II mitral regurgitation. These findings suggest that acceleration of left ventricle flow toward the mitral valve in systole is only recorded when there is hemodynamically significant mitral regurgitation that is approximately equal to angiographic grade III or IV. Recognition of this Doppler finding may help in the estimation of mitral regurgitation severity, especially in difficult diagnostic situations.
View details for PubMedID 2310590
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TRANSESOPHAGEAL ECHOCARDIOGRAPHY - AN INTRODUCTION FOR ULTRASONOGRAPHERS
JOURNAL OF DIAGNOSTIC MEDICAL SONOGRAPHY
1989; 5 (6): 316-321
View details for Web of Science ID A1989CF11400005
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THE HEMODYNAMIC-EFFECTS OF REPEATED BEDREST EXPOSURE
AVIATION SPACE AND ENVIRONMENTAL MEDICINE
1988; 59 (11): 1047-1054
Abstract
Hemodynamic changes were measured during stepwise exposure to lower-body negative pressure (LBNP) (5 min, -20, -30, and -40 mm Hg) in a group of seven physically active subjects before and after consecutive exposure to three 2-week bed rest periods. Bed rest exposures were separated by 3-week periods of ambulatory recovery. Dynamic exercise (68% max O2, 30 min each day) and isometric exercise (21% max leg extension, 30 min each day) performed during bed rest and reambulation failed to prevent deconditioning or accelerate the recovery process between bed rest exposures. Heart rate (HR) and end-diastolic volume index (EDVI) proved to be parameters showing greatest changes during LBNP. Heart rate increases at -40 mm Hg LBNP (compared to respective pre-LBNP levels) were 13.3%, 35.1%, and 51.0% for each of the pre-bed rest exposures, while respective changes after bed rest were 57.8%, 57.2%, and 75.5%. The significantly elevated HR responses during subsequent pre-bed rest (control) periods indicated incomplete recovery despite mild exercise and ambulation. Comparison of EDVI and HR revealed a similar linear regression relationship during LBNP before and after bed rest so that EDVI = 112.5-0.85 x HR, r = -0.97. We conclude from these findings that cardiovascular deconditioning for physically active individuals involves factors other than simple loss of plasma volume, requires at least 3 weeks or longer to return to the pre-bed rest state, and is not counteracted by the levels of aerobic and/or isometric exercise used in the present study.
View details for Web of Science ID A1988Q841400006
View details for PubMedID 3202785
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TASK FORCE 1 - THE DEFINITION AND ROLE OF ADULT CARDIOLOGISTS IN THE CHANGING SCENE OF CARDIOLOGY
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1988; 12 (3): 833-836
View details for Web of Science ID A1988P862300044
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The definition and role of adult cardiologists in the changing scene of cardiology.
Journal of the American College of Cardiology
1988; 12 (3): 833-836
View details for PubMedID 3403848
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TRANS-ESOPHAGEAL DOPPLER ECHOCARDIOGRAPHY
MAYO CLINIC PROCEEDINGS
1988; 63 (7): 726-728
View details for Web of Science ID A1988P341300007
View details for PubMedID 3386312
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METHODS FOR ESTIMATION OF STATISTICAL PROPERTIES OF ENVELOPES OF ULTRASONIC ECHOES FROM MYOCARDIUM
IEEE TRANSACTIONS ON MEDICAL IMAGING
1987; 6 (4): 281-291
Abstract
Several investigators have characterized various forms of heart disease from the statistical properties of envelopes of ultrasonic echos from myocardium. In particular, the mean-to-standard deviation ratio (MSR), skewness, and kurtosis of the envelope probability density function have been used for the detection of myocardial ischemia, infarction, reperfusion, and hypertrophy. In this paper, the effects of phenomena other than tissue acoustic properties upon estimates of statistical parameters are investigated. These include system characteristics (center frequency, bandwidth, beam width, etc.), sample volume dimensions, and tissue velocity. In myocardium, relatively small amounts of tissue are available for interrogation. It is shown that, under these limited data acquisition conditions, substantial systematic biases in the estimates of statistical parameters may occur. Analytic forms for errors in the envelope variance estimate are derived. Estimation of the envelope mean, variance, MSR, skewness, and kurtosis is investigated experimentally, using a commercial medical ultrasound scanner and a tissue-mimicking phantom.
View details for Web of Science ID A1987L191800001
View details for PubMedID 18244035
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Changes in Doppler echocardiographic indexes of left ventricular function as potential markers of acute cardiac rejection.
Circulation
1987; 76 (5): V86-92
Abstract
Changes in left ventricular filling and ejection as potential markers of cardiac allograft rejection were evaluated by serial Doppler echocardiography performed in 23 normal volunteers and within 24 hr of endomyocardial biopsy in 22 patients aged 14 to 53 years (mean 37). Peak aortic velocity, left ventricular ejection time index (ETI), isovolumic relaxation time (IVRT), mitral valve pressure half-time (PHT), peak early mitral flow velocity (M1), and velocity following donor atrial systole (M2) were measured without prior knowledge of endomyocardial biopsy findings. Biopsy specimens were graded histologically as: no rejection, mild rejection (cellular infiltrate), and moderate rejection (myocyte necrosis). A total of 120 biopsy-correlated Doppler echocardiographic studies were performed during 16 weeks after cardiac transplantation. Heart rate and mean arterial pressure were significantly higher in transplant recipients than in normal subjects. IVRT and PHT were significantly longer, while M1 and M2 were similar. Peak aortic velocity was higher in normal subjects than in transplant recipients, while ejection time was similar. Rejection of increasing severity was associated with a progressive shortening of IVRT and PHT and with an increase in M1 (p less than .0005 for all comparisons). Peak aortic velocity and ejection time index did not change significantly with rejection. These data indicate that acute cardiac rejection is accompanied by alteration in left ventricular filling dynamics detectable by Doppler echocardiography, without measureable changes in systolic function. These changes may provide noninvasive markers for surveillance of rejection.
View details for PubMedID 3311461
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CHANGES IN DOPPLER ECHOCARDIOGRAPHIC INDEXES OF LEFT-VENTRICULAR FUNCTION AS POTENTIAL MARKERS OF ACUTE CARDIAC REJECTION
CIRCULATION
1987; 76 (5): 86-92
Abstract
Changes in left ventricular filling and ejection as potential markers of cardiac allograft rejection were evaluated by serial Doppler echocardiography performed in 23 normal volunteers and within 24 hr of endomyocardial biopsy in 22 patients aged 14 to 53 years (mean 37). Peak aortic velocity, left ventricular ejection time index (ETI), isovolumic relaxation time (IVRT), mitral valve pressure half-time (PHT), peak early mitral flow velocity (M1), and velocity following donor atrial systole (M2) were measured without prior knowledge of endomyocardial biopsy findings. Biopsy specimens were graded histologically as: no rejection, mild rejection (cellular infiltrate), and moderate rejection (myocyte necrosis). A total of 120 biopsy-correlated Doppler echocardiographic studies were performed during 16 weeks after cardiac transplantation. Heart rate and mean arterial pressure were significantly higher in transplant recipients than in normal subjects. IVRT and PHT were significantly longer, while M1 and M2 were similar. Peak aortic velocity was higher in normal subjects than in transplant recipients, while ejection time was similar. Rejection of increasing severity was associated with a progressive shortening of IVRT and PHT and with an increase in M1 (p less than .0005 for all comparisons). Peak aortic velocity and ejection time index did not change significantly with rejection. These data indicate that acute cardiac rejection is accompanied by alteration in left ventricular filling dynamics detectable by Doppler echocardiography, without measureable changes in systolic function. These changes may provide noninvasive markers for surveillance of rejection.
View details for Web of Science ID A1987L004500016
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INTRAVENTRICULAR FLOW DURING ISOVOLUMIC RELAXATION - DESCRIPTION AND CHARACTERIZATION BY DOPPLER ECHOCARDIOGRAPHY
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1987; 10 (3): 539-546
Abstract
This study describes the characteristics of a prominent Doppler flow velocity signal representing intraventricular flow during left ventricular isovolumic relaxation. The flow during the isovolumic relaxation period was demonstrated in 60 subjects, including 7 with a normal heart, 26 with hypertrophic cardiomyopathy, 10 with aortic valve disease, 9 with a transplanted heart and 8 others. All had normal to hyperdynamic left ventricular systolic function with some degree of cavity obliteration as seen in the apical two-dimensional echocardiographic views. In contrast, this isovolumic relaxation period flow could not be demonstrated in the absence of cavity obliteration in any of 20 patients with either normal or diminished left ventricular systolic function. Isovolumic relaxation period flow was best recorded from the apical transducer position and was directed toward the apex in all patients. By pulsed wave, and with two-dimensional Doppler ultrasound, the isovolumic relaxation period flow originated within a narrow area in the medial portion of the left ventricle along the middle or basal segments of the interventricular septum, but was recorded over a larger area toward the apex. The peak isovolumic relaxation period flow velocity was recorded just basal to the area of cavity obliteration, usually at the level of the papillary muscles, and ranged from 0.4 to 2.3 m/s (mean of 1.0 m/s). This isovolumic relaxation period flow started with aortic valve closure and, in 50 of the 60 patients, it lasted throughout isovolumic relaxation until mitral valve opening. In the other 10 patients (all with hypertrophic cardiomyopathy), it lasted for only a part (mean 63%) of this period.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1987K104300009
View details for PubMedID 3624661
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GUIDELINES FOR OPTIMAL PHYSICIAN TRAINING IN ECHOCARDIOGRAPHY - RECOMMENDATIONS OF THE AMERICAN-SOCIETY-OF-ECHOCARDIOGRAPHY COMMITTEE FOR PHYSICIAN TRAINING IN ECHOCARDIOGRAPHY
AMERICAN JOURNAL OF CARDIOLOGY
1987; 60 (1): 158-163
Abstract
Over the past few years, the clinical use of echocardiography has continued to expand. Echocardiographic techniques are used widely to define normal and abnormal cardiac anatomy, evaluate cardiac chamber sizes and dynamics, assess valvular and pericardial diseases, detect intracavitary masses, measure pressure gradients across discrete stenoses, determine flow volumes, detect and assess the severity of valvular regurgitation, demonstrate and quantitate intracardiac shunts, and measure the timing of cardiac events. These and related applications have led to the increasing use of echocardiography in the diagnostic evaluation of many cardiac disorders. Echocardiography requires considerable theoretical knowledge, technical skill and practical experience to be used in an optimal manner. Previous publications have suggested guidelines for physician training in the techniques of M-mode and 2-dimensional echocardiography. The clinical applications of echocardiography continue to grow, however, and Doppler techniques for evaluating blood flow have become an established component of the echocardiographic evaluation of many disorders. This article presents the current recommendations of the American Society of Echocardiography as to the background knowledge, the nature and amount of practical experience, and the type of training site that are optimal for the training of physicians who take responsibility for the conduct and interpretation of echocardiographic studies.
View details for Web of Science ID A1987J057400033
View details for PubMedID 3604931
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WHEN SHOULD DOPPLER-DETERMINED VALVE AREA BE BETTER THAN THE GORLIN FORMULA - VARIATION IN HYDRAULIC CONSTANTS IN LOW FLOW STATES
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1987; 9 (6): 1294-1305
Abstract
In low flow states, underestimation errors occur when the Gorlin formula is used to calculate valve area. A model of valvular stenosis designed to examine changes in the hydraulic discharge coefficient (Cd) and coefficient of orifice contraction (Cc) may explain these errors. Unsteady flow was examined in a pulsatile pump model and in a dog model. Valve areas were calculated from pressure and flow data using: a modified form of the Gorlin formula (assuming constant values for Cd and Cc) and a corrected formula (with values of Cd and Cc obtained from steady state data). Valve area was also calculated using the continuity equation with velocity and flow data (constant Cc). Flow velocities were measured using a newly designed ultrasound Doppler catheter capable of resolving flow velocities of up to 5.5 m/s. Both the corrected formula and continuity equation were highly predictive of actual valve area (r = 0.99, slope or M = 0.96 and r = 0.99, M = 1.06, respectively). The modified Gorlin equation was less accurate and tended to underestimate valve areas (r = 0.87, M = 0.83). This underestimation was most notable at low rates of flow (Gorlin: r = 0.94, M = 0.53; continuity: r = 0.93, M = 0.81 and r = 0.94, M = 0.89, respectively) more accurately than the modified Gorlin formula (r = 0.69, M = 0.49). In patients with low cardiac output, hemodynamic formulas, such as the Gorlin formula, which assume a constant value for the hydraulic discharge coefficient (Cd), may be less accurate than formulas using either a corrected value of Cd or Doppler-determined flow velocity and mean systolic flow.
View details for Web of Science ID A1987H646300013
View details for PubMedID 3294968
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THEORETICAL-ANALYSIS OF A TECHNIQUE FOR THE CHARACTERIZATION OF MYOCARDIUM CONTRACTION BASED UPON TEMPORAL CORRELATION OF ULTRASONIC ECHOES
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
1987; 34 (3): 368-375
View details for Web of Science ID A1987H114500011
View details for PubMedID 18291859
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INFLUENCE OF RECIPIENT ATRIAL CONTRACTION ON LEFT-VENTRICULAR FILLING DYNAMICS OF THE TRANSPLANTED HEART ASSESSED BY DOPPLER ECHOCARDIOGRAPHY
AMERICAN JOURNAL OF CARDIOLOGY
1987; 59 (12): 1159-1163
Abstract
Recipient atrial remnants retain electrical and mechanical activity after orthotopic cardiac transplantation. This study investigated the influence of recipient atrial contraction timing on Doppler ultrasound mitral flow velocity curves, isovolumic relaxation time, peak early mitral flow velocity (M1), mitral valve pressure half-time and peak mitral flow velocity due to atrial systole (M2). Clearly identifiable recipient atrial electrical activity (P waves) was present in 7 of 10 patients studied early postoperatively 2 to 6 months (mean 2.5) (early group) and in 20 of 24 patients seen 1 to 11 years (mean 3) after transplantation (late group). Median age and gender distribution were similar in both groups. For analysis of its influence on isovolumic relaxation time, pressure half-time and M1, recipient atrial contraction was classified by its position in the cardiac cycle as early systole, late systole or diastole. For analysis of M2, it was classified as early diastole, late diastole or systole. Compared with its occurrence in diastole, recipient atrial contraction in late systole was associated with a shorter isovolumic relaxation time, shorter pressure half-time and higher M1. In early systole it was associated with a longer pressure half-time and lower M1 than in diastole; isovolumic relaxation time was unchanged. Recipient atrial contraction in early diastole resulted in a lower M2 than in systole, whereas simultaneous contraction of recipient and donor atria in late diastole resulted in an increase in M2. These results indicate that the timing of recipient atrial contraction and relaxation significantly influences left ventricular filling dynamics.
View details for Web of Science ID A1987H365700028
View details for PubMedID 3554953
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DOPPLER ECHOCARDIOGRAPHIC INDEXES OF DIASTOLIC FUNCTION AS MARKERS OF ACUTE CARDIAC REJECTION
TRANSPLANTATION PROCEEDINGS
1987; 19 (1): 2556-2559
View details for Web of Science ID A1987G101500265
View details for PubMedID 3547937
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ECHOCARDIOGRAPHIC EVALUATION OF SPACE-SHUTTLE CREWMEMBERS
JOURNAL OF APPLIED PHYSIOLOGY
1987; 62 (1): 278-283
Abstract
Echocardiographic measurements were obtained before and after space flight from 17 members of four shuttle crews. Measurements obtained 1 h after landing (L+0) compared with preflight values (n = 7) demonstrated an increase in heart rate (HR) (16 beats/min, 30.5%, P less than 0.05), mean arterial pressure (12%, P less than 0.05), and systemic vascular resistance (34%, P less than 0.05). End-diastolic volume index (EDVI) fell 17 ml/m2 (-23%, P less than 0.005) and stroke volume index (SVI) fell 15 ml/m2 (-28%, P less than 0.05). Repeat measurements taken 1-2 wk later (n = 17) demonstrated that HR had returned to normal (4 beats/min, P less than 0.05); however, EDVI remained significantly below preflight levels (-11%, P less than 0.005). End-systolic volume index (ESVI) was also still significantly lower (-23%, P less than 0.01). This delayed recovery occurred despite ability of the subjects to fully ambulate and exercise during the postflight period. These results indicate that spaceflight induces significant changes in heart volume affecting left ventricular function. The exact reasons for these specific changes remain unknown and will require additional measurements before, during, and after flight. The prolonged recovery period for the present subject group probably relates to their high level of aerobic conditioning.
View details for Web of Science ID A1987G454400039
View details for PubMedID 3558187
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Ultrasonic characterization of acute cardiac rejection from temporal evolution of echocardiograms.
journal of heart transplantation
1986; 5 (6): 425-429
Abstract
Two ultrasonic parameters that characterize cardiac contractile performance were tested for their ability to detect the early stages of acute rejection. Five dogs received heart transplants with a heterotopic abdominal model and were given echographic examinations 1, 4, and 8 days after surgery. The ultrasonic measurements were extracted from pairs of cross-sectional echocardiograms, separated in time by approximately half of a cardiac cycle. The contraction-related changes in the portions of the images corresponding to myocardium were characterized by ratio of mean video amplitude and image-pair correlation. Full-thickness biopsies were taken from the left and right ventricles after each examination so that the correlations between the ultrasonic measurements and the histologic state of the tissue could be determined. Each biopsy was ranked according to the following scale of increasing levels of rejection: 0 (normal), 1 (lymphocyte infiltration), 2 (focal necrosis), 3 (diffuse necrosis), 4 (presence of hemorrhages). The average histologic state for the left ventricle increased from 0.2 +/- 0.4 for the first examination, to 2.0 +/- 0.7 for the second, and 3.6 +/- 0.5 for the third. Similar results were obtained for the right ventricle. The progressions of mean amplitude ratio and correlation were 1.55 +/- 0.14, 1.49 +/- 0.17, 1.19 +/- 0.15, and 0.22 +/- 0.10, 0.28 +/- 0.10, 0.74 +/- 0.25, respectively. Thus in this experiment, these parameters were useful for distinguishing advanced stages of rejection from the normal state and from mild rejection.
View details for PubMedID 3302175
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DOPPLER ECHOCARDIOGRAPHIC MEASUREMENT OF AORTIC-VALVE AREA IN AORTIC-STENOSIS - A NONINVASIVE APPLICATION OF THE GORLIN FORMULA
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1986; 8 (5): 1059-1065
Abstract
Thirty adult patients with aortic stenosis had Doppler echocardiography within 1 day of cardiac catheterization. Noninvasive measurement of the mean transaortic pressure gradient was calculated by applying the simplified Bernoulli equation to the continuous wave Doppler transaortic velocity recording. Stroke volume was measured noninvasively by multiplying the systolic velocity integral of flow in the left ventricular outflow tract (obtained by pulsed Doppler ultrasonography) by the cross-sectional area of the left ventricular outflow tract (measured by two-dimensional echocardiography). Non-invasive measurement of aortic valve area was calculated by two methods. In method 1, the Gorlin equation was applied using Doppler-derived mean pressure gradient, cardiac output and systolic ejection period. Method 2 used the continuity equation. These noninvasive measurements were compared with invasive measurements using linear regression analysis, and mean pressure gradients correlated well (r = 0.92). Aortic valve area by either noninvasive method also correlated well with cardiac catheterization values (method 1, r = 0.87; method 2, r = 0.88). The sensitivity of Doppler detection of critical aortic stenosis was 0.86, with a specificity of 0.88 and a positive predictive value of 0.86. Cardiac output measured nonsimultaneously showed poor correlation (r = 0.51). Doppler echocardiography can distinguish critical from noncritical aortic stenosis with a high degree of accuracy. Measurement of aortic valve area aids interpretation of Doppler-derived mean pressure gradient data when the gradients are in an intermediate range (30 to 50 mm Hg).
View details for Web of Science ID A1986E614200009
View details for PubMedID 3760380
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PATTERNS AND TIMING OF DOPPLER-DETECTED INTRACAVITARY AND AORTIC FLOW IN HYPERTROPHIC CARDIOMYOPATHY
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1986; 8 (5): 1047-1058
Abstract
This study describes the velocity characteristics of left ventricular and aortic outflow in 25 patients with hypertrophic "obstructive" cardiomyopathy. Systematic pulsed and continuous wave Doppler analysis combined with phonocardiography and M-mode echocardiography was used to establish the pattern and timing of outflow in the basal and provoked states. This analysis suggests that 1) the high velocity left ventricular outflow jet can be reliably discriminated from both aortic flow and the jet of mitral regurgitation using Doppler ultrasound; 2) the Doppler velocity contour responds in a characteristic fashion to provocative influences including extrasystole and Valsalva maneuver; 3) the onset of mitral regurgitation occurs well before detectable systolic anterior motion of the mitral valve; 4) left ventricular flow velocities are elevated at the onset of systolic anterior motion of the mitral valve, suggesting a significant contribution of the Venturi effect in displacing the leaflets and chordae; 5) the high velocities of the outflow jets are largely dissipated by the time flow reaches the aortic valve; and 6) late systolic flow in the ascending aorta is nonuniform, with formation of distinct eddies that may contribute to "preclosure" of the aortic valve.
View details for Web of Science ID A1986E614200008
View details for PubMedID 2876020
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ULTRASONIC CHARACTERIZATION OF CANINE MYOCARDIUM CONTRACTION
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
1986; 33 (4): 347-353
View details for Web of Science ID A1986C424400001
View details for PubMedID 18291795
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TIMING OF ABNORMAL INTERVENTRICULAR SEPTAL MOTION AFTER CARDIOPULMONARY BYPASS OPERATIONS - LACK OF INJURY PROVED BY PREOPERATIVE, INTRAOPERATIVE, AND POSTOPERATIVE ECHOCARDIOGRAPHY
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
1986; 91 (4): 619-623
Abstract
Abnormal interventricular septal motion after cardiopulmonary bypass is a widely known occurrence. The cause and exact timing of this phenomenon remain unclear. We have studied 21 patients prospectively with preoperative, intraoperative, and postoperative two-dimensional and M-mode echocardiograms. Intraoperative studies were obtained with the pericardium closed and open and after completion of procedures performed with cardiopulmonary bypass. Fourteen patients had coronary artery bypass graft operations alone. Six patients had valve replacement with or without coronary bypass, and one patient had removal of a left atrial myxoma. All patients had normal interventricular septal motion before the operation, and none had abnormal septal motion intraoperatively. Four to eight days postoperatively, the septum still thickened normally in all patients, with five patients having normal, nine patients abnormal, and seven patients paradoxical interventricular septal motion. Studies in 11 patients 1 to 4 months postoperatively showed no change from the early postoperative study. The pericardium was left open postoperatively in all patients. Six patients were studied a few hours after sternal closure and all had abnormal interventricular septal motion. We conclude that abnormal interventricular septal motion after cardiac operations is not due to injury of the septum, adhesion formation, or loss of pericardial constraint. Closure of the chest wall itself, with the pericardium left open, is associated with this abnormality.
View details for Web of Science ID A1986A823600019
View details for PubMedID 3959582
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COMPARISON OF DOPPLER-DERIVED PRESSURE-GRADIENT TO THAT DETERMINED AT CARDIAC-CATHETERIZATION IN ADULTS WITH AORTIC-VALVE STENOSIS - IMPLICATIONS FOR MANAGEMENT
AMERICAN JOURNAL OF CARDIOLOGY
1986; 57 (8): 644-648
Abstract
Over a 1-year period cardiac catheterization was performed in 58 patients, mean age 66 years, who had elevated aortic blood flow velocity (more than 1.7 m/s) by continuous-wave Doppler echocardiography. Doppler echo signals were initially judged acceptable for quantitative analysis in 95% of patients, usually from the apical transducer position. Cardiac catheterization was performed within a mean of 8 days (60% within 1 day) of the Doppler echo study. The aortic valve mean pressure gradients at catheterization ranged from 0 to 93 mm Hg. The linear correlation coefficient (r value) between the mean pressure gradient determined by Doppler echocardiography and catheterization was 0.87. The correlation was maintained in 15 patients with aortic regurgitation (r = 0.91) and in 16 patients with significant coronary artery disease (r = 0.93). In the 16 patients with reduced cardiac output (mean 3.2 liters/min, range 2.2 to 3.9) the correlation was 0.81. A strategy for using the Doppler echo-calculated pressure gradient to manage patients with valvular aortic stenosis (AS) was derived by investigating the relation of the Doppler echo gradient to the aortic valve area in 35 patients with no aortic regurgitation detected at catheterization. All 12 patients with a Doppler echo mean gradient of less than 30 mm Hg had an aortic valve area of more than 0.75 cm2 and all 11 patients with a Doppler echo mean gradient of more than 50 mm Hg had an aortic valve area of less than 0.75 cm2.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1986A393000027
View details for PubMedID 3953450
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EFFECT OF VARIATION IN PQ INTERVAL ON PATTERNS OF ATRIOVENTRICULAR VALVE MOTION AND FLOW IN PATIENTS WITH NORMAL VENTRICULAR-FUNCTION
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1986; 7 (3): 595-602
Abstract
M-mode echocardiography and Doppler ultrasonography were used to study patterns of atrioventricular (AV) valve motion and flow in five patients with complete heart block, normal ventricular function and an implanted dual chamber pacemaker with programmable PQ intervals. Changes in AV valve motion and flow patterns resulting from steady state changes in PQ interval over the range studied (75 to 250 ms) were similar in all patients. Events reflecting AV valve opening and rapid ventricular filling bore a constant temporal relation to the Q wave and were unaffected by changes in PQ interval. Events reflecting atrial contraction occurred progressively earlier in diastole with lengthening of the PQ interval, until superimposition of atrial contraction on rapid ventricular filling at a PQ interval of 250 ms. The duration of mid-diastolic slow ventricular filling and overall diastole, defined with respect to an open valve, decreased with lengthening of the PQ interval. The onset of AV valve closure (A point) bore a constant temporal relation to the P wave, indicating that atrial systole initiated valve closure. However, completion of AV valve closure occurred progressively earlier with respect to the P wave as the PQ interval was decreased. This suggests an increasing contribution of ventricular systole to completion of AV valve closure with decreasing PQ interval. End-diastolic and end-systolic ventricular and atrial dimensions were independent of the PQ interval.
View details for Web of Science ID A1986A298300018
View details for PubMedID 3950239
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Beta blockade in the compensation for bed-rest cardiovascular deconditioning: physiologic and pharmacologic observations.
American journal of cardiology
1985; 55 (10): 114D-119D
Abstract
Beta-adrenergic blockade using intravenous propranolol was evaluated as a countermeasure for bedrest-induced cardiovascular deconditioning. After propranolol administration, tolerance to a maximal lower body negative pressure (LBNP) test after bed rest improved to at least the -70 mm Hg level; following this, there was a sharp decrease in tolerance time. Propranolol decreased mean tolerance time by 36% (17.7 +/- 2.4 to 11.5 +/- 2.3 minutes) before bed rest, and by only half as much (16.6%) after bed rest (14.4 +/- 2.2 to 12.0 +/- 2.3 minutes). Systemic vascular resistance was maintained and even slightly increased after propranolol despite a decrease in cardiac output, indicating beta 2-adrenergic blockade. Heart rates at all levels of LBNP were lower during beta blockade, yet increases occurred with successive LBNP steps, both before and after bed rest, indicating withdrawal of parasympathetic nervous system influences. Results support the use of propranolol in small dosages as a countermeasure after bed rest, and the findings may also be extrapolated to space-flight deconditioning.
View details for PubMedID 3993544
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BETA-BLOCKADE IN THE COMPENSATION FOR BED-REST CARDIOVASCULAR DECONDITIONING - PHYSIOLOGIC AND PHARMACOLOGIC OBSERVATIONS
AMERICAN JOURNAL OF CARDIOLOGY
1985; 55 (10): D114-D119
View details for Web of Science ID A1985AGH4300019
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DETECTION OF ENDOCARDITIS-ASSOCIATED PERIVALVULAR ABSCESSES BY TWO-DIMENSIONAL ECHOCARDIOGRAPHY
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1985; 5 (3): 647-653
Abstract
The development of a perivalvular abscess as a complication of infective endocarditis adds appreciably to the expected morbidity and mortality of patients, but such abscesses are seldom recognized by available noninvasive techniques. Therefore, two-dimensional echocardiographic findings in 22 patients with perivalvular abscess found at surgery or necropsy were compared with those in 24 patients without abscess in a retrospective but blinded study. Forty-six valves were examined (31 aortic and 15 mitral, 35 prosthetic and 11 native); 4.0 +/- 2.4 days (range 0 to 7) elapsed between echocardiography and surgery or necropsy. Patients with perivalvular abscess had a somewhat higher incidence of serious complications (emergency repeat valve replacement or death) than did patients with endocarditis alone (63 versus 35%, respectively, p less than 0.05). No single echocardiographic finding was frequently seen with a perivalvular abscess. A "typical" echo-free abscess was noted in only one patient; however, the presence of one or more of the following had a positive predictive value of 86% and a negative predictive value of 87% for the presence of perivalvular abscess: prosthetic valve rocking; sinus of Valsalva aneurysm, anterior aortic root thickness of 10 mm or greater, posterior aortic root thickness of 10 mm or greater or perivalvular density in a septum of 14 mm or greater. These predictive values, of course, apply only to patients with infective endocarditis going to surgery, and may assist the surgeon in knowing whether or not to expect an abscess.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1985ADP2100011
View details for PubMedID 3973262
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NONINVASIVE EVALUATION OF INTRACARDIAC PRESSURES USING DOPPLER ULTRASOUND - A CASE-STUDY OF PANVALVULAR REGURGITATION
CLINICAL CARDIOLOGY
1985; 8 (11): 565-571
Abstract
Doppler velocity signals from regurgitant valve flow can be used to calculate pressure gradients across incompetent valves by a modification of the Bernoulli equation. Analysis of these gradients provides clinically useful, noninvasive information about cardiac chamber pressures. This study presents an unusual case of cardiomyopathy with panvalvular regurgitation which demonstrates the major methods of pressure analysis using Doppler signals from regurgitant valves.
View details for Web of Science ID A1985ATD7800002
View details for PubMedID 4064381
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ECHOCARDIOGRAPHIC RECOGNITION OF PARASEPTAL STRUCTURES
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1985; 6 (4): 913-919
Abstract
Improved echocardiographic equipment provides detailed images of the heart and shows anatomic paraseptal structures previously not well defined. Echocardiograms were analyzed from 33 patients who later underwent cardiac transplantation, and the paraseptal structures noted were correlated with the pathologic specimens. Patterns associated with right ventricular chordae tendineae, the moderator band and the posterior papillary muscle are illustrated. Hypertrophic and fibrotic right ventricular trabeculae and left ventricular paraseptal bands are noted. These structures can be specifically sought and identified using the current generation of echocardiographs, thereby avoiding potential problems of septal definition and measurement.
View details for Web of Science ID A1985ASE5100034
View details for PubMedID 4031307
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MILDLY DILATED CONGESTIVE CARDIOMYOPATHY
CIRCULATION
1985; 72 (2): 302-309
Abstract
Five patients with only mildly dilated ventricles but other features typical of congestive cardiomyopathy underwent cardiac transplantation for class IV NYHA heart failure. The findings of clinical studies, cardiac catheterization, endomyocardial biopsy, and pathologic examination of the removed hearts in this group with mildly dilated congestive cardiomyopathy (MDCM) were compared with similar data in four patients with idiopathic restrictive cardiomyopathy (IRCM) and in 10 patients with typical dilated congestive cardiomyopathy (DCM). In comparison with the other groups, patients with MDCM had a higher incidence of familial cardiomyopathy (p = .02) and a shorter symptomatic period than patients with IRCM (p less than .02). Patients with both MDCM and DCM had globular hearts (with predominant left ventricular dilatation), congestive hemodynamics and poor left ventricular contractility (ejection fraction 12% to 19%), and high incidence of ventricular thrombi. Patients with IRCM showed normal ventricular size, marked atrial dilatation, restrictive hemodynamics, mild-to-moderate decrease in left ventricular contractility (ejection fraction 29% to 55%), and absence of ventricular thrombi. Cardiac index, ventricular wall thickness, and light microscopic findings were similar in the three groups of patients. Electron microscopy showed no myofibrillar loss in patients with IRCM but mild (partial) or moderate-to-severe (almost total) myofibrillar loss in those with MDCM and DCM, respectively. We conclude that end-stage congestive cardiomyopathy may occur without significant ventricular dilatation and patients with MDCM have heart sizes intermediate between those found in IRCM and DCM but their clinical, hemodynamic, and pathologic findings are virtually identical to those of patients with typical DCM.
View details for Web of Science ID A1985AMX1500009
View details for PubMedID 3159508
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THE ACCURACY OF DOPPLER ULTRASOUND MEASUREMENT OF PRESSURE-GRADIENTS ACROSS IRREGULAR, DUAL, AND TUNNEL-LIKE OBSTRUCTIONS TO BLOOD-FLOW
CIRCULATION
1985; 72 (3): 577-584
Abstract
The accuracy of Doppler-estimated pressure gradients in the setting of irregular, multiple, and tunnellike stenoses was investigated. An in vitro model of the left ventricular outflow tract was designed to allow pulsatile flow of red cells in saline across valve orifices from 0.01 to 2.5 cm2. Simultaneous pressure gradients were estimated by both Doppler and direct-pressure manometer techniques. Gradients obtained by the two methods correlated well for valve areas in the range of clinical stenoses at pressure gradients of 10 to 150 mm Hg (r = .97 to .99). Model valves were constructed with a large orifice (0.75 to 1.25 cm2) placed beside a small orifice (0.02 to 0.25 cm2) in the same outflow tract. A distinct jet was recorded when the Doppler transducer was aligned with each orifice. Doppler-estimated gradients for each pair of large and small orifices were identical and correlated well with those measured by manometer (r = .97 to .99). Irregularly shaped orifices also provided good correlation between the two methods (r = .98 to .99). Pulsatile flow was generated through long tunnellike obstructions with cross-sectional areas varying from 0.06 to 1.25 cm2. Tunnel length varied from 0.1 to 4 cm. Tunnel areas above 0.25 cm2 gave good Doppler-to-manometer correspondence at all tunnel lengths. Doppler underestimated manometer-determined values in the 0.25 cm2 tunnel by 8% at 3 cm and by 15% at 4 cm. In the 0.06 cm2 tunnel, Doppler underestimated manometer gradients by 12%, 15%, 32%, and 42% at lengths of 1, 2, 3, and 4 cm, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
View details for Web of Science ID A1985APY7700020
View details for PubMedID 3893794
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ULTRASONIC TISSUE CHARACTERIZATION - DETECTION OF ACUTE MYOCARDIAL ISCHEMIA IN DOGS
CIRCULATION
1985; 72 (1): 193-199
Abstract
Ultrasonic tissue characterization is a new area of investigation in the field of cardiac ultrasound. The amplitude and frequency of the ultrasound signal are normally altered as the signal penetrates through tissue. It is assumed that the amplitude distribution and frequency shift of diseased or edematous tissue are different than those of normal tissue. A statistical approach to the analysis of the unprocessed radiofrequency signal in the amplitude domain was used to study the effect of acute myocardial ischemia on the parameter mean amplitude/standard deviation of the amplitude (MSR). Ten dogs were anesthetized and underwent left lateral thoracotomy. Baseline mean MSR from the interventricular septum was 1.99 +/- 0.05, but increased by 30 min after coronary artery occlusion and started to plateau at 1 hr (mean 2.24 +/- 0.06). Reproducibility in noninfarcted myocardium (left ventricular inferoposterior wall) was good, with a mean MSR of 2.00 +/- 0.05 at baseline and 1.98 +/- 0.04 3 to 4 hr later. There was no difference in mean MSR when data were obtained through chest wall and when they were obtained directly from the surface of the heart. We conclude that statistical analysis in the amplitude domain of the unprocessed radiofrequency signal can detect acute myocardial ischemia within 30 min after coronary artery occlusion, provides reproducible measurements, and is unaffected by chest wall filtering.
View details for Web of Science ID A1985ALE0300025
View details for PubMedID 3891130
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COMPARATIVE RECOGNITION OF LEFT-VENTRICULAR THROMBI BY ECHOCARDIOGRAPHY AND CINEANGIOGRAPHY
BRITISH HEART JOURNAL
1985; 53 (1): 36-42
Abstract
Studies performed in 47 patients, 11 of whom underwent surgery for aneurysmectomy and 36 of whom underwent cardiac transplantation, were reviewed to assess the diagnostic accuracies of cross sectional echocardiography and cineangiography in detecting left ventricular mural thrombi and the effect of anticoagulation treatment on the incidence of such thrombi. Cross sectional echocardiography in 37 patients and cineangiography in 26 (16 patients were examined by both methods) were analysed independently by sets of two observers experienced in the respective methods. All four observers were blinded to the pathological or surgical findings regarding mural thrombus. Mural thrombus was confirmed by pathological investigation in 14 of 47 (30%) cases; 11 of these 14 patients had intra-aneurysmal thrombi. The negative predictive value was quite good for both methods, but cross sectional echocardiography had a superior positive predictive value. This was due both to detailed soft tissue resolution by cross sectional echocardiography and to overdetection of mural thrombi by cineangiography in cases of aneurysms without mural thrombi. Mural thrombi were present in three of 20 patients with preceding anticoagulation and in 10 of 19 patients without anticoagulation. The results emphasise that cross sectional echocardiography is more reliable than cineangiography in recognising thrombi.
View details for Web of Science ID A1985AAK3700007
View details for PubMedID 3966950
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A NEW METHOD FOR ASSESSING RIGHT-SIDED HEART PRESSURES USING ENCAPSULATED MICROBUBBLES - A PRELIMINARY-REPORT
WESTERN JOURNAL OF MEDICINE
1985; 143 (4): 463-468
Abstract
A new noncatheter method for measuring pressures of the right side of the heart uses specially manufactured microbubbles of carbon dioxide injected into the peripheral venous system. Sudden expansion of these bubbles in the cardiac chambers causes bubble oscillations at a frequency that is primarily a function of surrounding pressure. The oscillations are recordable by a microphone on the chest wall. The preliminary experience has been in dogs and further development is needed before we can begin clinical testing of the method. In its current form, the potential for measuring higher systolic pressures seems better than that for lower diastolic pressures.
View details for Web of Science ID A1985ASH4000001
View details for PubMedID 3937336
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NONINVASIVE INTRACARDIAC PRESSURE MEASUREMENT USING DOPPLER ULTRASOUND
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1985; 6 (4): 757-758
View details for Web of Science ID A1985ASE5100007
View details for PubMedID 3897341
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AN IMPROVED STOCHASTIC APPROACH TO RF AMPLITUDE ANALYSIS IN ULTRASONIC CARDIAC TISSUE CHARACTERIZATION
ULTRASONIC IMAGING
1984; 6 (2): 139-151
Abstract
We carried out a series of studies to improve the reproducibility of methods for ultrasonic myocardial tissue characterization using a stochastic approach to amplitude analysis of radiofrequency signals previously reported from our laboratory. Analysis of transducer scanner characteristics, data acquisition and processing, and data display from studies in tissue phantoms permit us to define some features of a parameter for expression of tissue character. The ratio of mean to standard deviation of the amplitude histogram from our system is explored as now implemented in our laboratory for reproducible measurements. The theoretical basis for understanding the utility of this method in defining tissue architecture and pathologic conditions requires further work.
View details for Web of Science ID A1984SU51800003
View details for PubMedID 6539976
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COMPUTERIZED QUANTITATIVE-ANALYSIS OF LEFT-VENTRICULAR WALL MOTION BY TWO-DIMENSIONAL ECHOCARDIOGRAPHY
CIRCULATION
1984; 70 (2): 242-254
Abstract
Quantitative detection of left ventricular segmental wall motion abnormalities by any modality depends on the reference system used because of the dynamic geometry of contraction and cardiac motion within the thorax. To assess the feasibility and accuracy of quantitative analysis of left ventricular wall motion by two-dimensional echocardiography, we studied 61 subjects with the use of 44 different reference methods in each of three echocardiographic views: the parasternal short-axis view at the levels of the mitral valve and of the papillary muscles and an apical four-chamber view. The three major groups of reference systems used were those with a fixed external reference, a floating reference correcting for translation, and systems correcting for both translation and rotation. In the first part of this study the end-diastolic and end-systolic outlines of 20 normal subjects were stored in a computer and composite data of these 20 subjects were plotted to obtain a 95% confidence interval for measured normal fractional change for each reference method. In the second part of the project an additional prospective group of 10 normal subjects and a group of 31 "abnormal" patients had their left ventricular wall motion analyzed by similar methods and the results were compared with all the confidence intervals. One reference method was selected for each two-dimensional echocardiographic view based on the highest sensitivity and specificity found by statistical analysis; a floating-reference system including translation was found to be optimal for the apical four-chamber and parasternal short-axis views at the level of the mitral valve and a fixed external reference system was optimal for the short-axis view at the papillary level. The percent fractional shortening of radial dimensions (radial methods) and the percent fractional change in area measurements (area methods) during the cardiac cycle were also calculated at 5, 10, 20, 30 and 45 degree intervals around the outline perimeter for each subject according to each of the 44 different methods. Area methods yielded the same specificity and sensitivity as radial dimension analysis methods at 5 to 45 degree intervals. Ten normal subjects underwent repeat echocardiography within 2 days of their first study to examine day-to-day variation. Average change in mean contraction from day to day was 7% to 9% for radial methods and 9% to 13% for area methods. In conclusion, we present a computerized system for unbiased selection of optimal methods of analysis of left ventricular wall motion by two-dimensional echocardiography.(ABSTRACT TRUNCATED AT 400 WORDS)
View details for Web of Science ID A1984TB41300013
View details for PubMedID 6733880
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ECHOCARDIOGRAPHIC RECOGNITION AND IMPLICATIONS OF VENTRICULAR HYPERTROPHIC TRABECULATIONS AND ABERRANT BANDS
CIRCULATION
1984; 70 (5): 836-842
Abstract
The accuracy of two-dimensional echocardiography in the recognition of aberrant ventricular bands and pathologic trabeculations (hypertrophic, fibrotic, or both) was assessed in 35 patients who underwent cardiac transplantation and pathologic examination. At pathologic study the prevalence of specific intracavitary structures ranged from 28% to 43%. Left ventricular thrombi were found in 12 patients (34%) and right ventricular thrombi in three (9%). Echocardiography accurately defined left ventricular aberrant bands and left ventricular thickened or fibrotic trabeculations. Bands, trabeculations, and thrombi each showed characteristic echocardiographic patterns. In the right ventricle, these structures were recognized, but accurate discrimination among them was not possible by echocardiography. Aberrant bands and pathologic trabeculations mimicked or obscured fresh or organized thrombi in three patients on two-dimensional echocardiography. Left ventricular longitudinal bands and pathologic right ventricular trabeculations obscured the interventricular septal border in four patients; the presence of these abnormalities could lead to the erroneous diagnosis of asymmetric septal hypertrophy on M mode echocardiography. By expressing the accuracy of two-dimensional echocardiography in the recognition of left ventricular anomalous bands, our results support the feasibility of prospective studies to clarify their clinical significance.
View details for Web of Science ID A1984TQ91400010
View details for PubMedID 6488497
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NONINVASIVE ESTIMATION OF RIGHT VENTRICULAR SYSTOLIC PRESSURE BY DOPPLER ULTRASOUND IN PATIENTS WITH TRICUSPID REGURGITATION
CIRCULATION
1984; 70 (4): 657-662
Abstract
We evaluated the accuracy of a noninvasive method for estimating right ventricular systolic pressures in patients with tricuspid regurgitation detected by Doppler ultrasound. Of 62 patients with clinical signs of elevated right-sided pressures, 54 (87%) had jets of tricuspid regurgitation clearly recorded by continuous-wave Doppler ultrasound. By use of the maximum velocity (V) of the regurgitant jet, the systolic pressure gradient (delta P) between right ventricle and right atrium was calculated by the modified Bernoulli equation (delta P = 4V2). Adding the transtricuspid gradient to the mean right atrial pressure (estimated clinically from the jugular veins) gave predictions of right ventricular systolic pressure that correlated well with catheterization values (r = .93, SEE = 8 mm Hg). The tricuspid gradient method provides an accurate and widely applicable method for noninvasive estimation of elevated right ventricular systolic pressures.
View details for Web of Science ID A1984TN45300019
View details for PubMedID 6478568
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A PHYSICIANS VIEW OF ECHOCARDIOGRAPHIC IMAGING
HEWLETT-PACKARD JOURNAL
1983; 34 (10): 13-16
View details for Web of Science ID A1983RN44700005
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STANDARDIZED INTRACARDIAC MEASUREMENTS OF TWO-DIMENSIONAL ECHOCARDIOGRAPHY
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1983; 2 (5): 934-938
Abstract
Thirty-five healthy adults were studied by two-dimensional echocardiography to attempt to standardize a simple method for measurement of intracardiac dimensions. Both ventricles and the atria and aorta were measured in five different views: parasternal long-axis, parasternal short-axis at the level of the aortic valve, the chordae tendineae and the papillary muscles and an apical four chamber view. The minor axis of each chamber was measured in all five views; the major axis in the apical four chamber view also was measured. All measurements are presented as a range of values (mean and 2 standard deviations about the mean); the mean value is given as well as the absolute range of values measured. Normalization according to body surface area is also presented. Data from these multiple views allow assessment of asymmetry of cardiac chambers in normal subjects. The mean minor axis dimension at end-diastole of the right ventricle in the parasternal long-axis view (1.9 to 3.8 cm) was 13.6% smaller than in the four chamber view (2.2 to 4.4 cm), whereas the minor axis dimension of the left ventricle in the parasternal long-axis view (3.5 to 6.0 cm) was only 1.1% larger than in the four chamber view (3.3 to 6.0 cm). Therefore, the right ventricular minor axis dimensions are not interchangeable. Reproducibility in 10 subjects for all dimensions showed a maximal variability of 4.8%. These values permit a standardized and expeditious method for measuring intracardiac dimensions by two-dimensional echocardiography.
View details for Web of Science ID A1983RN88600019
View details for PubMedID 6630768
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RAPID, SEMIAUTOMATED TECHNIQUE FOR ESTIMATING LEFT-VENTRICULAR VOLUME
AMERICAN HEART JOURNAL
1983; 106 (3): 521-527
Abstract
A new system for rapidly quantitating left ventricular volume using two-dimensional echocardiography is tested. This system relies on a microprocessor built into a sector scanner that immediately calculates the length, area, and volume of the chamber being imaged using the mathematical model of an ellipsoid of revolution. The calculations are made after the observer superimposes a smooth calibrated ellipse outline on the endocardium imaged with the sector scanner. We report our experience with this system in 50 patients with a variety of cardiac disorders and compare the left ventricular volumes measured with those obtained using cineangiography, M-mode, and more detailed light pen tracing techniques. Correlations between volumes measured with the elliptical calipers and angiography were good (r = 0.820, SEE +/- 38.8 ml) (n = 100), but not as good as that between light pen tracing of the echo images and angiography (r = 0.847, SEE +/- 27.8 ml) (n = 22). M-mode correlated less well with angiography (r = 0.789; SEE +/- 42.1 ml) (n = 90). We conclude that the calibrated ellipse system is rapid and simple to use, while its accuracy matches previous studies using two-dimensional echocardiography to quantitate left ventricular volume.
View details for Web of Science ID A1983RE66300014
View details for PubMedID 6881026
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REPRODUCIBILITY OF LEFT-VENTRICULAR VOLUMES BY TWO-DIMENSIONAL ECHOCARDIOGRAPHY
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1983; 2 (3): 506-513
Abstract
Reproducibility may be as important as absolute accuracy in assessing the utility of an echocardiographic method of left ventricular volume estimation for epidemiologic or physiologic studies. The magnitude of differences between measurements in the same subjects from day to day must be defined before any quantitative technique can be used reliably to document "real" changes in heart volume over time. Two-dimensional echocardiograms were performed serveral days apart in 30 subjects, including 20 normal subjects and 10 patients with stable coronary heart disease. Analyses of light-pen tracings provided measurements of end-diastolic volume, endsystolic volume and derived ejection fraction on both days, and differences in individual subjects between days were quantitated. Beat to beat, interobserver and intraobserver variability also were assessed. Although group values changed little from day to day, individual volume changes were substantial in some cases. Confidence limits for individual measurements were derived from analyses of intrasubject variability and were as follows: end-diastolic volume +/- 15%, end-systolic volume +/- 25%, ejection fraction +/- 10%. Confidence limits in a larger group of subjects were narrower; in a group of 30 subjects, changes of greater than 2% in end-diastolic volume, 5% in end-systolic volume and 2% in ejection fraction most likely represent real change. Intraobserver variability was minimal, but interobserver and beat to beat variability were of sufficient magnitude to suggest that serial measurements on a given subject be made ideally by a single person and that several cycles be averaged for a given measurement.
View details for Web of Science ID A1983RE86300014
View details for PubMedID 6875114
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INVIVO ULTRASONIC TISSUE CHARACTERIZATION OF HUMAN INTRACARDIAC MASSES
AMERICAN JOURNAL OF CARDIOLOGY
1983; 51 (1): 231-236
Abstract
Interactions between an ultrasonic signal and cardiac tissue have been used to characterize the histologic state of myocardium in vitro. To assess the utility of in vivo ultrasonic tissue characterization, stochastic analysis was applied to the digitized echocardiographic signals from 15 patients with 2-dimensional echocardiograms suggesting intracardiac masses. Ten subjects with echocardiograms suggesting mural thrombi underwent subsequent surgery or necropsy, which confirmed thrombi in 6 and revealed no thrombi (designated artifact) in 4. Five other patients had intracardiac tumors. The amplitudes within the digitized ultrasonic signals were displayed as histograms, which were described by a parameter k that represented the degree to which each histogram departed from a totally random probability density function. In 5 of 6 thrombi, k = 0, but in all 4 artifacts, k greater than 0. The sixth thrombus had k = 0.5 due to the specular effect of the interface between the thrombus' 2 lobes. All 5 tumors had k greater than 0. Ultrasonic tissue characterization using a stochastic analysis of backscatter can be performed in vivo and helps differentiate thrombus from artifact and tumor in the heart.
View details for Web of Science ID A1983PV79600039
View details for PubMedID 6849262
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VARIABILITY OF DIGITIZED ECHOCARDIOGRAPHY - SIZE, SOURCE, AND MEANS OF REDUCTION
AMERICAN JOURNAL OF CARDIOLOGY
1983; 51 (3): 576-582
Abstract
Digitization of M-mode echocardiograms provides useful information on left ventricular function, but its variability has been assessed rarely. Inter- and intraobserver (technical) variability of readers digitizing the same cardiac cycles, and variability between beats, days, and subjects (biologic) was determined. Technical variability was small for both standard dimensions (correlation coefficient r values 0.82 to 1.00) and rates of change (r values 0.70 to 0.98). Biologic variability was large with expected normal differences between 2 measurements (95% confidence limits) of 11 to 55% and 37 to 106% for standard dimensions and rates of change, respectively. By averaging measurements of 5 beats from each of 2 days, the expected normal differences are reduced to 6 to 32% and 23 to 63% for standard dimensions and rates of change. This study emphasizes the large biologic variability in rates of change of digitized left ventricular measurements. Normal variation between studies can be reduced and real physiologic or pathologic changes perceived best if many beats from more than 1 day are measured.
View details for Web of Science ID A1983QB10100037
View details for PubMedID 6823872
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TWO-DIMENSIONAL ECHOCARDIOGRAPHIC ASSESSMENT OF BIOPROSTHETIC VALVE DYSFUNCTION AND INFECTIVE ENDOCARDITIS
JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY
1983; 2 (4): 597-606
Abstract
Two-dimensional echocardiography of Hancock porcine heterograft valves was evaluated by correlation with clinical, hemodynamic, angiographic and pathologic findings in 80 patients. Ninety-five aortic and mitral bioprostheses were categorized by the type of valvular abnormality: group I, dysfunction due to primary tissue failure (41 valves); group II, dysfunction due to paravalvular leakage without infection (5 valves); group III, infective endocarditis with or without hemodynamic dysfunction (28 valves); and group IV, control cases without dysfunction or infection (21 valves). Increased size of a bioprosthetic leaflet image (minimal dimensions 3 x 5 mm) was observed in 46% (19 of 41) of cases with primary tissue failure and in 62% (10 of 16) of cases with leaflet vegetations due to endocarditis. Prolapse of leaflet echoes to below the level of the bioprosthetic sewing ring occurred in 76% (28 of 37) of cases with torn leaflets and also in 46% (6 of 13) of valves with vegetations on intact leaflets. Antegrade extension of leaflet echoes to beyond the level of the stents, observed in 4 of 16 cases with leaflet vegetations, was the only echocardiographic sign distinguishing leaflet infection from leaflet degeneration. Aortic bioprostheses with ring dehiscence affecting 40 to 90% of the anular circumference showed motion discordant with the motion of the adjacent aortic root and native anulus. Although echocardiographic abnormalities are frequently observed with bioprosthetic leaflet degeneration or infection, the echocardiographic appearance often does not distinguish between these two major complications and is best interpreted concurrently with other clinical and laboratory assessment.
View details for Web of Science ID A1983RJ81500001
View details for PubMedID 6886226
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CONDUCTION DISTURBANCES RELATED TO THE SITE AND SEVERITY OF MITRAL ANULAR CALCIFICATION - A TWO-DIMENSIONAL ECHOCARDIOGRAPHIC AND ELECTROCARDIOGRAPHIC CORRELATIVE STUDY
AMERICAN JOURNAL OF CARDIOLOGY
1983; 51 (10): 1644-1649
Abstract
To investigate an apparent association of mitral anular calcium (MAC) and electrocardiographic abnormalities, the relation between location of 2-dimensional (2-D) echo-quantified MAC and conduction disturbances was studied in 140 patients with MAC (MAC group) and in 135 age- and sex-matched patients without MAC (control group). The MAC group was subclassified regarding site and severity of calcium in the mitral anulus. The site of MAC was defined as Type I, near the primary conduction system--MAC located in the medial segment and/or extending to the anterior mitral leaflet; and Type II--MAC located at the central and/or lateral segments away from the primary conduction system. The severity of MAC was graded on 2-D echocardiography as mild (localized within 1 segment) and moderate to severe (greater than 1 segment). Seven patients with MAC, and only 1 control subject, had pacemakers in place. Conduction disturbances were present in 44 (31%) of 140 patients with MAC, and in 37 (27%) of 135 control patients (difference not significant). But there were more conduction disturbances in patients with Type I MAC (53%) than in those with Type II MAC (26%) (p less than 0.01). Specifically, complete left bundle branch block and intraventricular conduction delay were more prevalent when MAC was near the conduction system. Conduction disturbances also were more prevalent in patients with Type I MAC than in the control group: intraventricular conduction delay (Type I, 12% versus control, 4%; p less than 0.05) and total conduction disturbances (53 versus 28%; p less than 0.01). These data suggest that moderate to severe degrees of MAC located near the conduction system are associated with conduction disturbances, especially intraventricular conduction delay.
View details for Web of Science ID A1983QS52700014
View details for PubMedID 6858870
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PREOPERATIVE INVASIVE TESTING IN MITRAL-STENOSIS - INDICATIONS BASED ON ASSESSMENT OF DIAGNOSTIC YIELD
AMERICAN JOURNAL OF CARDIOLOGY
1983; 51 (7): 1116-1121
Abstract
The role of preoperative invasive testing in mitral stenosis was assessed in 82 patients undergoing cardiac catheterization for isolated mitral stenosis. The patients were diagnosed by physical examination and echocardiography and were considered for surgical treatment primarily to relieve dyspnea. They had no precordial murmur attributable to an aortic valvular lesion and had no history of chest pain. The presence of mitral stenosis was confirmed at catheterization in all patients. All 38 patients in New York Heart Association functional class III and 8 of 9 patients in class IV had hemodynamic confirmation of mitral disease warranting operation. Although a mitral gradient was present in all 35 patients in class II, operation was not recommended in 9 (26%) of 35 with normal or mildly elevated pulmonary arterial wedge pressure. Invasive testing did not increase preoperative knowledge of aortic. tricuspid, or pulmonary valvular lesions which required surgical treatment. Coronary arteriography was performed in 44 patients (54%) and identified 4 patients with luminal narrowing (greater than 70% diameter reduction) affecting 1 or 2 arteries. These results suggest that preoperative invasive testing in patients with mitral stenosis is unnecessary when symptoms are moderate to severe and clinical evidence of aortic valvular or coronary artery disease is absent. However, preoperative cardiac catheterization is indicated in patients with mild symptoms to avoid unnecessary or premature mitral valve operations.
View details for Web of Science ID A1983QH81400014
View details for PubMedID 6837456
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CARDIAC LOCALIZATION OF TRANS-VASCULAR BIOPTOME USING TWO-DIMENSIONAL ECHOCARDIOGRAPHY
AMERICAN JOURNAL OF CARDIOLOGY
1983; 51 (1): 219-223
Abstract
Two-dimensional (2-D) echocardiography was added to standard fluoroscopic localization of transvascular endomyocardial biopsy in 7 children with heart muscle disease whose ages were 6 months to 18 years. One left ventricular and 11 right ventricular biopsies were carried ot without complications using the fluoroscopic-echocardiographic technique. Two-dimensional echocardiographic monitoring has the advantages of reducing radiation exposure and providing anatomic information about intracardiac structures as well as bioptome localization. Lateral beam spread and reverberation artifacts represent potential problems with 2-D echocardiography, but they did not cause significant difficulties in this study.
View details for Web of Science ID A1983PV79600037
View details for PubMedID 6849260
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ECHOCARDIOGRAPHY IN ACQUIRED HEART-DISEASE
CIRCULATION
1983; 67 (4): 935-938
View details for Web of Science ID A1983QG71000033
View details for PubMedID 6337743
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NON-INVASIVE DIAGNOSIS OF LEFT ATRIAL-MYXOMA
WESTERN JOURNAL OF MEDICINE
1983; 138 (5): 722-725
View details for Web of Science ID A1983QR18200026
View details for PubMedID 6603714
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INTRODUCTION - ECHOCARDIOGRAPHIC EVALUATION OF VENTRICULAR-FUNCTION - AN OVERVIEW
AMERICAN JOURNAL OF CARDIOLOGY
1982; 49 (5): 1311-1312
View details for Web of Science ID A1982NH12800031
View details for PubMedID 7064855
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MITRAL AND AORTIC-VALVE ORIFICE AREA IN NORMAL SUBJECTS AND IN PATIENTS WITH CONGESTIVE CARDIOMYOPATHY - DETERMINATION BY 2 DIMENSIONAL ECHOCARDIOGRAPHY
AMERICAN JOURNAL OF CARDIOLOGY
1982; 49 (5): 1191-1196
Abstract
Previous determinations of normal valve orifice areas have been mainly from postmortem studies. In this study mitral and aortic valve orifice area were determined from two dimensional echocardiograms in 20 normal subjects and 20 patients with congestive cardiomyopathy. Mitral valve orifice area was larger than quoted in standard textbooks. Both mitral and aortic valve orifice area were reduced in patients with cardiomyopathy. Valve opening was assessed relative to left ventricular and aortic root size. The ratio of mitral valve orifice area to left ventricular cross-sectional area was markedly reduced in patients with cardiomyopathy compared with normal subjects. The ratio of aortic valve orifice area to aortic root size also was reduced in patients with cardiomyopathy. Anterior mitral leaflet E point-septal separation was similar to that in previous reports contrasting normal subjects with patients with myopathy. Among patients with cardiomyopathy, mitral E point-septal separation was primarily a function of left ventricular size and was not significantly correlated with fractional shortening or ejection fraction within this group having uniformly poor systolic function.
View details for Web of Science ID A1982NH12800013
View details for PubMedID 7064844
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RELATION OF P-S4 INTERVAL TO LEFT-VENTRICULAR END-DIASTOLIC PRESSURE
BRITISH HEART JOURNAL
1982; 47 (3): 270-276
Abstract
Reports have suggested that the interval between P wave onset and the fourth heart sound (P-S4 interval) reflects changes in left ventricular myocardial stiffness. We made simultaneous measurements of the P-S4 or atrial electrogram to S4 (A-S4) interval and left ventricular pressure in 19 patients with coronary artery disease who were studied before and after atrial pacing. Thirteen patients developed angina accompanied by significant rises in their end-diastolic pressure and a consistent decrease in P-S4 or A-S4 interval; whereas the six patients who had atrial pacing without the development of angina had no change in end-diastolic pressure, P-S4, or A-S4 interval. The resting data showed in inverse correlation between left ventricular end-diastolic pressure and the P-S4 interval. In addition, the P-S4 interval let us discriminate between patients with normal and abnormal end-diastolic pressure (greater than 15 mmHg).
View details for Web of Science ID A1982NE68300011
View details for PubMedID 7059403
View details for PubMedCentralID PMC481133
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CARDIOVASCULAR PHYSIOLOGY IN A CASE OF HETEROTOPIC CARDIAC TRANSPLANTATION
AMERICAN JOURNAL OF CARDIOLOGY
1982; 49 (5): 1301-1307
Abstract
Successful heterotopic cardiac transplantation in a 24 year old man with end stage cardiomyopathy provided an opportunity to study cardiovascular physiology. The donor and native hearts, functioning independently in parallel, were studied by serial physical examination, electrocardiography, echocardiography, nuclear angiography and cardiac catheterization. Results indicated that the donor left heart assumed the predominant role in supplying systemic output, possibly contributing to decreasing function of the patient's own (native) heart. Analysis of serial nuclear angiograms revealed an initial postoperative ejection fraction of 52 and 21 percent in the donor and the native left ventricle, respectively; repeat studies 3 months postoperatively showed values of 50 and 9 percent, respectively, indicating significant deterioration in native left ventricular cardiac function. Observation of valve motion of the native heart showed major irregularities of the aortic valve in contrast to seemingly normal, regular mitral valve motion. These data rise interesting questions regarding interpretation of valve motion as an indicator of ventricular function.
View details for Web of Science ID A1982NH12800029
View details for PubMedID 7039290
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AORTITIS IN ANKYLOSING-SPONDYLITIS - EARLY DETECTION OF AORTIC ROOT ABNORMALITIES WITH 2 DIMENSIONAL ECHOCARDIOGRAPHY
AMERICAN JOURNAL OF CARDIOLOGY
1982; 49 (4): 680-686
Abstract
Mild aortic root dilatation, cusp thickening and subvalvular fibrous ridges have been reported as characteristic in patients with ankylosing spondylitis and aortic regurgitation. Thirty-five patients with ankylosing spondylitis (10 also had Reiter's syndrome) without clinically apparent cardiac involvement were studied using phased array two dimensional and sector-directed M mode echocardiography to determine the prevalence of aortic abnormalities. Aortic root dimensions were measured at the aortic anulus, at the tip of the cusps and 0.5 to 1.5 cm above the cusps. The two dimensional echocardiographic study was also analyzed for qualitative abnormalities. The dimensions were compared with those in 20 normal men and among patient subgroups separated according to age, duration and severity of ankylosing spondylitis and presence of qualitative abnormalities. With one exception, no abnormally increased aortic dimensions suggestive of aortic dilatation were found in any group. However, two patients had aortic dimensions greater than 4.2 cm at the valve (normal 4.0 cm or less). Also, six patients had discrete areas of increased bright echoes below the left or noncoronary cusps suggestive of a subaortic "bump" and two of the six patients had increased aortic cusp echoes suggestive of thickening or fibrosis, or both. These changes tended to occur more commonly in older patients and those with more severe disease. It is concluded that aortic root changes suggestive of inflammation or fibrosis, or both, occur in asymptomatic patients with ankylosing spondylitis and are detectable on two dimensional echocardiography. Dilatation usually does not occur without aortic regurgitation.
View details for Web of Science ID A1982NF97900007
View details for PubMedID 7064818
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ADVANCING THE DIAGNOSIS OF LEFT ATRIAL-MYXOMA
CHEST
1982; 82 (5): 522-524
View details for Web of Science ID A1982PP55200005
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INVITRO EVALUATION OF AN ULTRASONIC 3-DIMENSIONAL IMAGING AND VOLUME SYSTEM
ULTRASONIC IMAGING
1982; 4 (2): 126-139
View details for Web of Science ID A1982NQ95600003
View details for PubMedID 7201694
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M-MODE ECHOCARDIOGRAPHIC ASSESSMENT OF LEFT-VENTRICULAR FUNCTION
AMERICAN JOURNAL OF CARDIOLOGY
1982; 49 (5): 1312-1318
View details for Web of Science ID A1982NH12800032
View details for PubMedID 7064856
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THE CARDIAC EFFECTS OF D-DISOPYRAMIDE AND L-DISOPYRAMIDE IN NORMAL SUBJECTS - A NON-INVASIVE STUDY
CIRCULATION
1982; 66 (2): 447-453
Abstract
Commercially available disopyramide is a racemic mixture of equal parts of dextrorotatory (d-) and levorotatory (l-) optical isomers. We studied the cardiac effects of i.v. administration of each isomer and the racemic mixture (dl-) in six normal males by digitized echocardiography, systolic time intervals and ECG. Both isomers and the racemic mixture produced equally marked dose-dependent negative inotropic effects (28.1 +/- 11.8% mean maximal reduction in fractional shortening of left ventricular dimension) and diastolic effects (28.6 +/- 24.1% mean maximal reduction in peak left ventricular filling rate). However, only the d-isomer prolonged QTc duration (by 13.6 +/- 5.2% at maximum, p less than 0.001 vs l-isomer). We conclude that disopyramide, in the doses used, produces marked adverse effects on left ventricle systolic and diastolic function in normal subjects independent of optical rotation. The production of these effects by the l-isomer without affecting QTc duration suggests different subcellular mechanisms for the myocardial depressant effects and some of the electrophysiologic effects of disopyramide.
View details for Web of Science ID A1982NY67700029
View details for PubMedID 7094252
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TWO-DIMENSIONAL ECHOCARDIOGRAPHIC ANALYSIS OF SEGMENTAL LEFT-VENTRICULAR WALL MOTION BEFORE AND AFTER CORONARY-ARTERY BYPASS-SURGERY
CIRCULATION
1982; 66 (5): 1025-1035
Abstract
Twenty patients with coronary artery disease were studied with two-dimensional echocardiography the day before saphenous vein bypass graft surgery. Serial studies were obtained 7.4 +/- 2.5 (+/- SD) and 43.4 +/- 13.1 days postoperatively to qualitatively assess the effect of bypass surgery on regional wall motion. Changes in segmental wall motion were assessed semiquantitatively by assigning a segmental wall motion score to each of nine echocardiographically defined segments. Preoperatively, 18% of the segments moved abnormally. The mean overall segmental wall motion score did not change significantly, as shown by comparing the postoperative studies with the preoperative study. However, there was a significant worsening in the septal motion (apical and basal) and a significant improvement in posterior wall motion (apical and basal) after bypass surgery. Anterior and lateral wall motion were not significantly changed. Nonseptal segments that were normal preoperatively usually remained normal; abnormal nonseptal segments usually improved or were unchanged by surgery. The motion of septal segments, however, generally worsened postoperatively whether they were normal or abnormal preoperatively. We conclude that segmental wall motion assessed by two-dimensional echocardiography may improve after revascularization surgery, but the interventricular septum shows impaired motion. This effect of coronary artery bypass on wall motion is better demonstrated relatively late after operation than early in the postoperative course, as has been done in some previous studies.
View details for Web of Science ID A1982PM98800018
View details for PubMedID 6982113
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THE CONCEPT OF 3 DIMENSIONAL RESOLUTION IN ECHOCARDIOGRAPHIC IMAGING
ULTRASOUND IN MEDICINE AND BIOLOGY
1982; 8 (3): 237-247
View details for Web of Science ID A1982NP24300001
View details for PubMedID 7101572
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LIMITATIONS OF COMPARING LEFT-VENTRICULAR VOLUMES BY 2 DIMENSIONAL ECHOCARDIOGRAPHY, MYOCARDIAL MARKERS AND CINEANGIOGRAPHY
AMERICAN JOURNAL OF CARDIOLOGY
1982; 50 (3): 512-519
View details for Web of Science ID A1982PE99400013
View details for PubMedID 7113934
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SCREENING FOR ATRIAL SEPTAL-DEFECTS WITH ECHOCARDIOGRAPHY
JOURNAL OF CARDIOVASCULAR MEDICINE
1981; 6 (5): 490-?
View details for Web of Science ID A1981LQ98800006
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THE RELATIONSHIP OF PULMONARY VALVE MOTION TO THE MOTION OF SURROUNDING CARDIAC STRUCTURES - A TWO-DIMENSIONAL AND DUAL M-MODE ECHOCARDIOGRAPHIC STUDY
CIRCULATION
1981; 64 (1): 107-112
Abstract
To assess the relationship of late diastolic pulmonary valve motion to motion of adjacent cardiac structures, we performed two-dimensional and dual M-mode echocardiography on 15 pulmonary normotensive (group A) and nine pulmonary hypertensive subjects (group B). Simultaneous pulmonary valve and posterior aortic wall a-waves were less prominent in group B than in group A (p less than 0.001), and their amplitudes were linearly related within each group (r = 0.83). Analysis of two-dimensional studies confirmed a relationship between pulmonary valve and posterior aortic wall late diastolic motion. No subject had independent presystolic motion of the pulmonary valve within the pulmonary artery. Subjects with shallow a-waves had impaired left atrial emptying compared with those with normal a-wave amplitudes (p less than 0.01). We conclude that the pulmonary valve a-wave does not represent independent valvular displacement, but rather, reflects motion of the entire cardiac base. Variations in a-wave morphology may result, at least in part, from the effects of altered ventricular geometry and compliance on left atrial emptying.
View details for Web of Science ID A1981LU46100016
View details for PubMedID 7237706
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SPONTANEOUS DISSECTION OF THE ASCENDING AORTA DIAGNOSED BY TWO-DIMENSIONAL ECHOCARDIOGRAPHY
CHEST
1981; 80 (5): 587-591
Abstract
In two patients with acute dissection of the ascending aorta, the diagnosis was made with two-dimensional echocardiography and confirmed by aortography. The echocardiograms localized the intimal flap and false channel in both cases. Although clinical evaluation and indicated radiologic studies remain the primary modalities of diagnosis in acute aortic dissection, two-dimensional echocardiography may be a useful additional diagnostic technique.
View details for Web of Science ID A1981MP64800015
View details for PubMedID 7297150
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THE USE OF ECHOCARDIOGRAPHY IN DIAGNOSING CULTURE-NEGATIVE ENDOCARDITIS
CIRCULATION
1981; 64 (3): 641-646
Abstract
We reviewed M-mode and two-dimensional echocardiographic findings in 11 patients with abacteremic endocarditis to study the application of echocardiography in this setting. All patients had negative blood cultures but underwent surgery that confirmed the presence of active infective endocarditis. The infection involved native valves in five patients and prosthetic valves in six patients. Valvular masses were identified in eight patients. The other three patients, who had prosthetic aortic valves, had diastolic mitral valve vibration characteristic of aortic regurgitation. One of these also showed dehiscence of the prosthesis. Three patients had poorly defined clinical illnesses and echocardiography was a prime element in the diagnosis because valvular masses were identified. The operation was facilitated by knowledge of the mass indicated by echocardiography in these eight cases. Also, the surgical approach was affected by knowledge of dehiscence and perivalvular abscess formation in two cases each.
View details for Web of Science ID A1981MB94200028
View details for PubMedID 7020979
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INVITRO QUANTITATION OF CANINE LEFT-VENTRICULAR VOLUME BY PHASED-ARRAY SECTOR SCAN
CARDIOLOGY
1981; 67 (1): 1-11
Abstract
Ultrasonic sector-scan images can delineate the entire circumference of the canine left ventricle in vitro. This study was undertaken to (1) assess the accuracy of sector scanning for estimating canine left ventricular volume in vitro compared to volume estimates by M-mode echo in the same hearts and (2) determine the optimal techniques for estimating left ventricular volume with sector scanning. 16 volumes (1 volume from 8 hearts and 2 volumes from 4 hearts) were estimated by obtaining sector-scan images from orthogonal long-axis, short-axis and apical views. The sector-scan volumes were calculated by single and biplane area-length methods, as well as biplane Simpson's rule methods, and compared to measured left ventricular volumes. M-mode echo volumes were calculated by cubing the mid-ventricular minor-axis diameter. Sector-scan views containing a long-axis dimension plus the short-axis dimension of the left ventricle had a high correlation with true left ventricular volume while sector-scan views not containing a long-axis view showed only a fair correlation with volume. M-mode echo produced a poor estimate of the true left ventricular volume. It is concluded that (1) sector scanning can provide highly accurate in vitro volume estimates of canine left ventricles which is superior to estimates derived by M-mode echocardiographic methods and (2) the optimal sector-scan views for estimating left ventricular volume are those that make the fewest assumptions about left ventricular geometry and have the greatest amount of dimensional information.
View details for Web of Science ID A1981KV35600001
View details for PubMedID 7459904
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CARDIAC DIMENSIONS AND PERFORMANCE AFTER EITHER ARM OR LEG ENDURANCE TRAINING
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
1981; 13 (5): 303-309
Abstract
We have recently reported improved exercise performance with untrained limbs in 10 men after 11 wk of either arm (N = 5) or leg (N = 5) endurance training. To examine the changes in cardiac function produced by short-term training, we used echocardiography to measure cardiac function at rest, and systolic time intervals (STIs) to measure cardiac function during trained and untrained limb exercise. We repeated all studies after autonomic blockade with atropine and propranolol in order to observe non-autonomic changes in cardiac function. Training had little effect on cardiac size or performance at rest, although with autonomic blockade, cardiac mass increased in the leg-training group and resting left ventricular ejection time (LVET) was prolonged when the two training groups were combined. During submaximal exercise with both trained and undrained limbs and at similar heart rates before and after training, LVET for the combined groups was increased with and without autonomic blockade. This increase in LVET is most consistent with an increased cardiac stroke volume. Short-term endurance training appears to result in improved exercise cardiac function that is in part independent of altered autonomic control or adaptations in trained skeletal muscle.
View details for Web of Science ID A1981MX86900006
View details for PubMedID 7321827
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ROLE OF ECHOCARDIOGRAPHY IN DIAGNOSIS AND MANAGEMENT OF VALVULAR HEART-DISEASE
MODERN CONCEPTS OF CARDIOVASCULAR DISEASE
1981; 50 (6): 31-36
View details for Web of Science ID A1981LS86500001
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APPARENT ASYMMETRIC SEPTAL HYPERTROPHY DUE TO ANGLED INTER-VENTRICULAR SEPTUM
AMERICAN JOURNAL OF CARDIOLOGY
1980; 46 (3): 386-392
View details for Web of Science ID A1980KG48100005
View details for PubMedID 7191198
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DIAGNOSIS OF LEFT-VENTRICULAR THROMBUS BY TWO-DIMENSIONAL ECHOCARDIOGRAPHY
EUROPEAN JOURNAL OF CARDIOLOGY
1980; 11 (3): 235-239
View details for Web of Science ID A1980JZ68700007
View details for PubMedID 7389805
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INTRA-PERICARDIAL ABNORMALITIES IN PATIENTS WITH PERICARDIAL-EFFUSION - FINDINGS BY TWO-DIMENSIONAL ECHOCARDIOGRAPHY
CIRCULATION
1980; 61 (3): 568-572
Abstract
Ten patients with pericardial fluid who also had striking band-like intrapericardial echoes by two-dimensional ultrasonic sector scanning are reported. Four patients had prior mediastinal radiation and four patients had severe renal disease. One patient had purulent pericarditis and one patient had traumatic hemopericardium. The two-dimensional images permitted recognition of loculation of fluid and led to the suspicion of thickened pericardial membranes. Three postradiation patients had both tamponade and constriction; tamponade alone was present in four additional patients. These data are preliminary but suggest that such findings by two-dimensional echocardiography should alert us to consider an effusive-constrictive form of pericardial disease.
View details for Web of Science ID A1980JG17000016
View details for PubMedID 7353247
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MITRAL ANNULAR CALCIFICATION - CLINICAL AND ECHOCARDIOGRAPHIC FEATURES
ACTA CARDIOLOGICA
1980; 35 (3): 189-201
Abstract
One hundred records from patients with the single or two-dimensional echocardiographic (2DE) diagnosis of mitral annular calcification (MAC) were analyzed. 2DE manifestations of MAC included a characteristic bright structure located at the junction of the A-V groove and posterior mitral leaflet. Sixteen of the 100 patients had idiopathic hypertrophic subaortic stenosis (IHSS), a 44% (16/36) incidence in all patients with IHSS having echoes during the study period. IHSS patients with MAC were significantly older (mean 61 years vs. 43 years, p < .005) than 20 other IHSS patients without MAC studied during the same period. Both IHSS patients and non-IHSS patients with MAC had significantly lower serum calcium levels than normals or the IHSS patients without MAC. These observations support the view that the pathogenesis of MAC is related to degenerative changes from aging and increased stress on the mitral apparatus. Alterations in calcium metabolism possibly contribute to calcium deposition in the mitral annulus.
View details for Web of Science ID A1980KL84600003
View details for PubMedID 6969962
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NON-INVASIVE QUANTIFICATION OF EXPERIMENTAL CANINE MYOCARDIAL INFARCT SIZE USING TWO-DIMENSIONAL ECHOCARDIOGRAPHY
EUROPEAN JOURNAL OF CARDIOLOGY
1980; 11 (3): 215-225
Abstract
In order to study whether wall motion abnormalities detected by two-dimensional (2D) echocardiography can be quantified and correlated with infarct size, we compared wall motion abnormalities viewed by 2D echocardiography in experimental canine infarction with post-mortem infarct size. Nineteen mongrel dogs underwent left anterior descending coronary artery snare occlusion. They were sacrificed 6 h later. Infarct sizing was done by technetium 99-m stannous pyrophosphate scintigraphy of the excised, sliced left ventricles. Fourteen dogs had both 2D echo wall motion abnormalities and infarctions. Four dogs failed to develop infarction and had no or minimal wall motion abnormalities. Inter-observer variation in 2D echocardiographic measurements was small. Wall motion abnormalities correlated with infarct size both in the 14-dog subgroup with infarction (r = 0.75, P less than 0.003) and all the 18 dogs that completed the protocol (r = 0.87, P less than 0.001). Thus, wall motion abnormalities in experimental canine myocardial infraction can be roughly quantified by 2D echocardiography and correlated with post-mortem infarct size measured by scintigraphy.
View details for Web of Science ID A1980JZ68700005
View details for PubMedID 7389803
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THE SOURCE OF ULTRASOUND CONTRAST EFFECT
JOURNAL OF CLINICAL ULTRASOUND
1980; 8 (2): 121-127
Abstract
Evidence that microbubbles are the main sources of ultrasound contrast in injected solutions has been largely indirect. To investigate this directly, we examined freshly agitated indocyanine green, freshly agitated water, commercially prepared precision microbubbles (diameter 75 +/- 25 mu) in gelatin, carbonated water, "degassed" indocyanine green solution, and "degassed" water in one or more of four different assay systems. Only fluids with microbubbles produced ultrasound contrast. Injected contrast material rose in a water bath at a rate that identified it as being caused by microbubbles. Indocyanine green and gelatin surface tensions were measured and found to be low (43 dynes/cm2), thus explaining their tendency to stabilize the microbubbles that cause ultrasound contrast effect when injected and to hold foam after agitation. The force of hand injections (force similar to that used clinically through catheters and 19-gauge or 23-gauge needles) was below the force needed to cause cavitation or ultrasound contrast effect. Microbubble content could be quantified by the decrease in amplitude of the echo from a structure distant to the microbubbles. We conclude that that the ultrasound contrast effect seen in peripherally injected fluids is caused by microbubbles present in the injectant. The contrast is not due to cavitation at needle tips, and it can be quantified over a limited range. Improved design for a peripheral contrast agent is suggest.
View details for Web of Science ID A1980JP18500004
View details for PubMedID 6767744
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ECHOCARDIOGRAPHY - M-MODE AND TWO-DIMENSIONAL METHODS
ANNALS OF INTERNAL MEDICINE
1980; 93 (6): 844-856
Abstract
We review the basic similarities and differences of currently used M-mode and two-dimensional (2D) echocardiography. Discrete categories of disease are used to show the relative strengths of M-mode and 2D methods. The format of 2D echocardiography is well suited to analyze congenital heart disease, consequences of coronary artery disease, and distortions of anatomy due to acquired heart disease. Rapid structure movement is preserved with M-mode recording, facilitating detailed analysis of motion. The vast clinical experience with M-mode echocardiography can now be augmented by 2D echocardiography, but combination of 2D and M-mode methods is optimal for understanding each type of ultrasound recording and for best serving the patient.
View details for Web of Science ID A1980KV10800018
View details for PubMedID 7447194
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CLINICAL UTILITY OF 2 DIMENSIONAL ECHOCARDIOGRAPHY IN INFECTIVE ENDOCARDITIS
AMERICAN JOURNAL OF CARDIOLOGY
1980; 46 (3): 379-385
View details for Web of Science ID A1980KG48100004
View details for PubMedID 7415982
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Two dimensional echocardiographic quantification of infarct size alteration by pharmacologic agents.
American journal of cardiology
1979; 44 (2): 257-262
Abstract
In 27 closed chest dogs left ventricular wall motion abnormalities assessed quantitatively with two dimensional echocardiography were used as a measure of myocardial infarct size, and the change in extent of segmental wall motion abnormalities due to drug intervention early after infarction was evaluated. The extent of wall motion abnormalities was measured with echocardiography before and at 20 and 40 minutes and 5 1/2 hours after coronary occlusion. Three subgroups of dogs received, respectively, an infusion of nitroglycerin, phenylephrine or saline solution. Infarct size was measured with technetium pyrophosphate scintigraphy of the excised left ventricle. The infarct size correlated well with the extent of wall motion abnormalities before death. Wall motion was initially similar among the three groups but was significantly improved after treatment with nitroglycerin (P less than 0.025), remained stable with continued saline infusion and worsened significantly (P less than 0.05) after treatment with phenylephrine. Two dimensional echocardiography can be used to quantify experimental canine myocardial infarction and assess the effect of nitroglycerin.
View details for PubMedID 223427
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VENTRICULAR SEPTAL-DEFECT NOTED BY 2-DIMENSIONAL ECHOCARDIOGRAPHY
CHEST
1979; 76 (4): 455-457
View details for Web of Science ID A1979HP30400020
View details for PubMedID 477436
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2-DIMENSIONAL ECHOCARDIOGRAPHIC FEATURES OF BICUSPID AORTIC-VALVE
CHEST
1979; 75 (4): 434-440
Abstract
The two-dimensional cross-sectional echocardiographic diagnosis of bicuspid aortic valves is described and compared with results of M-mode echocardiograms. Aortic valve anatomy was determined in 19 selected patients by angiography, and confirmed in five by direct surgical visualization. Using an eccentricity index (EI) of 1.3 or greater as diagnostic of bicuspid aortic valve, M-mode correctly identified anatomy in 14 of 19 valves (74 percent), although EI varied in several patients. For two-dimensional diagnosis of bicuspid aortic valve, short axis cross section was preferred, and criteria included number of cusps seen in real time motion, irregularity of folding of cusp margins, and location of commissural insertions. Two-dimensional echocardiography correctly identified anatomy in 18 of 19 valves (95 percent). Long axis cross section disclosed valvular doming in all 8 patients in whom doming was observed angiographically, correlating with hemodynamic findings. Two-dimensional echocardiography aids in the detection of bicuspid aortic valve in a suspected population, can give an estimate of valve gradients, and explains variability in M-mode findings. As such, two-dimensional echocardiography is a valuable tool in the noninvasive diagnosis of the bicuspid aortic valve.
View details for Web of Science ID A1979GR06600008
View details for PubMedID 446130
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DIAGNOSIS OF LEFT-VENTRICULAR THROMBI BY 2-DIMENSIONAL ECHOCARDIOGRAPHY
BRITISH HEART JOURNAL
1979; 42 (3): 261-265
Abstract
Sixteen patients had two-dimensional echocardiographic diagnosis of the presence or absence of left ventricular thrombi and anatomical, radiological, or clinical confirmation of the diagnosis. Eleven patients had positive diagnoses, which were confirmed in 10 and possibly incorrect in one. Five other records were reviewed because the patients had undergone aneurysmectomy after two-dimensional echocardiograms: three were true negative and two were false negative studies.
View details for Web of Science ID A1979HP17600003
View details for PubMedID 508446
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CARDIAC ANATOMY VIEWED SYSTEMATICALLY WITH 2-DIMENSIONAL ECHOCARDIOGRAPHY
CHEST
1979; 75 (5): 579-585
Abstract
The details of three-dimensional cardiac anatomy are complex, and structure recognition is difficult in tomograms produced with recently developed two-dimensional ultrasonic sector scanners. This article presents a method we have found useful for systematic inclusion of most cardiac structures during such echocardiographic examinations. Orthogonal planes, aligned parallel and perpendicular to the long or major left ventricular axis, are obtained from each of three transducer positions on the body surface. Moving this X-Y image plane through the heart perpendicular to the plane (z axis) allows the viewer to integrate the images into a mental picture of the whole structure. The illustrations are oriented as they are displayed by ultrasonic sector scanners so they aid rapid recognition of cardiac structures.
View details for Web of Science ID A1979GU61100014
View details for PubMedID 436487
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2 DIMENSIONAL ECHOCARDIOGRAPHIC ASSESSMENT OF PATIENTS WITH BIO-PROSTHETIC VALVES
AMERICAN JOURNAL OF CARDIOLOGY
1979; 43 (3): 510-519
Abstract
The clinical utility of two dimensional echocardiography in assessing bioprosthetic and left ventricular function was studied in 40 consecutive patients 1 week to 60 months after valve replacement surgery. These patients were referred to obtain normal baseline studies as well as to evaluate complications:suspected endocarditis, embolic phenomena and congestive heart failure of unknown cause. Independent M mode echocardiograms were also obtained in each patient. Confirmation of ultrasonic studies was by cardiac catheterization with angiography, surgery and pathologic study in 10 patients; cardiac catheterization with angiography alone in 7 patients; surgery and pathologic study in 3 patients; autopsy in 3 patients; blood cultures to confirm or exclude endocarditis in 10 patients; and confirmation on clinical grounds in 7 patients. Technically adequate two dimensional studies were recorded in 39 of 40 subjects. Two dimensional echocardiography accurately assessed 15 of 16 patients with an abnormal bioprosthetic valve and a normal left ventricle (1 of 16 patients had a false positive two dimensional echocardiogram); 8 of 8 patients suspected to have prosthetic valve or left ventricular dysfunction but who were normal; 7 of 7 patients with a normal prosthesis and an abnormal left ventricle; the one patient with an abnormal valve and left ventricle; and 7 of 7 clinically normal patients who were referred for baseline studies. In summary, the two-dimensional echocardiogram demonstrated a 97 percent diagnostic accuracy rate which was significantly greater than the 67 percent (P less than 0.001) for M mode echocardiography in the same group of patients. It is concluded that two dimensional echocardiography has excellent diagnostic accuracy in assessing bioprosthetic and left ventricular function and is superior to M mode echocardiography in evaluating patients after such valve replacement.
View details for Web of Science ID A1979GL34000007
View details for PubMedID 420102
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ACUTE MITRAL VALVULAR OBSTRUCTION FROM INFECTIVE ENDOCARDITIS - ECHOCARDIOGRAPHIC DIAGNOSIS AND REPORT OF THE 2ND SUCCESSFULLY TREATED CASE
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
1979; 78 (1): 128-130
Abstract
Severe mitral stenosis of rapid onset and progression was observed in a patient with infective endocarditis superimposed upon mild rheumatic mitral valvular stenosis. This severe stenosis resulted from large vegetations impinging upon the mitral valve orifice. Preoperative studies indicating mitral stenosis with vegetations and pulmonary edema were followed by emergency mitral valve replacement, which was sucessful.
View details for Web of Science ID A1979HC45000023
View details for PubMedID 449378
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SINGLE AND 2 DIMENSIONAL ECHOCARDIOGRAPHIC FEATURES OF THE INTER-ATRIAL SEPTUM IN NORMAL SUBJECTS AND PATIENTS WITH AN ATRIAL SEPTAL-DEFECT
AMERICAN JOURNAL OF CARDIOLOGY
1979; 43 (4): 816-819
Abstract
The interatrial septum is one of the least studied structures in M mode echocardiography. Two dimensional echocardiography has made it possible to record simultaneous M mode and two dimensional echocardiograms. Such studies were performed in 10 normal subjects and in 9 patients with a secundum atrial septal defect. In the short axis view of the base of the heart, the interatrial septum was visualized in the two dimensional studies as a linear echo running from the posterior aortic wall to the posterior atrial wall and in the M mode records as a series of dense echoes posterior to the aorta. The great variability in echo dropout of the interatrial septum made it impossible to distinguish the normal subjects from the patients with atrial septal defect. The dense echoes of the interial septum in the M mode records gave the false impression that they were filling the left atrium. These data indicate that (1) a secundum atrial septal defect cannot be reliably differentiated from a normal septum using these echocardiographic methods, and (2) the medial location of the interatrial septum should be appreciated so that it will not be confused with a left atrial mass.
View details for Web of Science ID A1979GP81100019
View details for PubMedID 425919
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EVALUATION OF THE ECHOCARDIOGRAM AS AN EPIDEMIOLOGIC TOOL IN AN ASYMPTOMATIC POPULATION
CIRCULATION
1979; 60 (4): 921-929
Abstract
An asymptomatic adult population of 196 men and women was studied with the echocardiogram to derive age- and sex-specific "normal" values for a number of clinically used echocardiograhic variables. The results are in general agreement with previously published normal values. Body position during the examination, age and sex influence the echocardiographic results; body surface area correction normalized most of these effects. The prevalence of occult abnormalities determined by the echocardiogram is 7%; the most common finding was mitral valve prolapse. Inter- and intraobserver variability was assessed. The interobserver differences found on analysis are statistically, but not clinically , significant. The echocardiogram appears to be a suitable tool to use in epidemiologic studies to detect selected cardiac abnormalities, but is limited for this purpose because some subjects in such a population cannot be adequately examined.
View details for Web of Science ID A1979HN05700026
View details for PubMedID 476895
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IDIOPATHIC HYPERTROPHIC SUB-AORTIC STENOSIS VIEWED BY WIDE-ANGLE, PHASED-ARRAY ECHOCARDIOGRAPHY
CIRCULATION
1979; 59 (6): 1206-1217
View details for Web of Science ID A1979GX15600016
View details for PubMedID 571310
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ECHOCARDIOGRAPHY IN DISCRETE SUB-AORTIC STENOSIS
CIRCULATION
1979; 59 (3): 506-513
View details for Web of Science ID A1979GK12000012
View details for PubMedID 761330
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CLINICAL UTILITY OF 2-DIMENSIONAL ECHOCARDIOGRAPHY
ACTA MEDICA SCANDINAVICA
1979: 68-78
View details for Web of Science ID A1979GY67500006
View details for PubMedID 286521
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RELIABILITY AND REPRODUCIBILITY OF 2 DIMENSIONAL ECHOCARDIOGRAPHIC MEASUREMENT OF THE STENOTIC MITRAL-VALVE ORIFICE AREA
AMERICAN JOURNAL OF CARDIOLOGY
1979; 43 (3): 560-568
View details for Web of Science ID A1979GL34000014
View details for PubMedID 420105
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2-DIMENSIONAL ECHOCARDIOGRAPHIC QUANTIFICATION OF INFARCT SIZE ALTERATION BY PHARMACOLOGIC AGENTS
AMERICAN JOURNAL OF CARDIOLOGY
1979; 44 (2): 257-262
View details for Web of Science ID A1979HE94300011
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LEFT-VENTRICULAR FUNCTION - ASSESSMENT BY WIDE ANGLE 2-DIMENSIONAL ULTRASONIC SECTOR SCANNING
ACTA MEDICA SCANDINAVICA
1979: 105-111
View details for Web of Science ID A1979GY67500010
View details for PubMedID 286501
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PERICARDIAL-EFFUSIONS IN PATIENTS WITH END-STAGE RENAL-DISEASE
BRITISH HEART JOURNAL
1978; 40 (2): 190-193
Abstract
Echocardiography has greatly increased the accurate recognition of pericardial effusion. Echocardiograms were performed prospectively on the total group of 35 stable asymptomatic patients on chronic haemodialysis to determine the incidence of pericardial effusion. Effusions were shown in 11 per cent (4/35); only 6 per cent (2/35) were estimated as greater than 100 ml. For comparison, records were reviewed retrospectively from 41 haemodialysis patients referred during a 27-month period for echocardiographic assessment of suspected pericardial effusion. These 41 patients came from a total group of 108 patients treated with chronic dialysis over this interval. Of 41 examined, 21 (51%) or 21 of 108 (19%) of the population at risk had an effusion. Of 21 with echocardiographic effusions, 15 (71%), or 15 of 41 (37%) of those with clinically suspected effusion, had more than 100 ml fluid. Gross (greater than 100 ml) pericardial effusions are infrequent in stable, asymptomatic patients with end-stage renal disease. When clinical findings suggest pericardial disease, the echocardiographic demonstration of over 100 ml pericardial fluid is indicative of new effusion, rather than coincidental pre-existing effusion.
View details for Web of Science ID A1978ET58700015
View details for PubMedID 637968
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LOCALIZATION OF PERICARDIAL-EFFUSION WITH WIDE ANGLE PHASED-ARRAY ECHOCARDIOGRAPHY
AMERICAN JOURNAL OF CARDIOLOGY
1978; 42 (6): 904-912
Abstract
Twenty-eight patients with proved pericardial effusions were studied in the left lateral decubitus position with an 80 degrees phased array sector scanner to determine the distribution of pericardial effusions of various sizes. Twenty-one of 28 patients were studied 2 minutes after assuming the sitting position to determine the change in the distribution of the effusions with postural change. In small volume effusions, the fluid was truly posterior at and below the atrioventricular groove. With moderate-sized effusions a more uniform distribution of the fluid was found, and with large effusions more fluid was visualized apically, posteromedially, laterally and anteriorly. Upright redistribution of the fluid was seen with moderate to large nonloculated effusions. Assumption of a uniform distribution of pericardial effusion used for M mode quantification is most valid for moderate effusions and less valid for small and large effusions. Imaging was performed in two additional patients with cardiac tamponade to assess qualitative changes in short axis ventricular volumes with respiration. The introduction of a pericardiocentesis needle was visualized. Clinical implications are discussed.
View details for Web of Science ID A1978GA77400003
View details for PubMedID 727141
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SINGLE AND 2-DIMENSIONAL ECHOCARDIOGRAPHIC VISUALIZATION OF EFFECTS OF SEPTAL MYECTOMY IN IDIOPATHIC HYPERTROPHIC SUB-AORTIC STENOSIS
CIRCULATION
1978; 58 (5): 850-860
Abstract
Although the postoperative hemodynamic and echocardiographic features of idiopathic hypertrophic subaortic stenosis have been studied, the expected consistent postoperative thinning of the interventricular septum has not been reported. In this study, the short-term effects of septal myectomy were evaluated in 16 patients. All patients were assessed with pre- and postoperative hemodynamic studies and M-mode echocardiograms, and six of the 16 patients had pre- and postoperative two-dimensional echocardiograms. The mean resting preoperative gradient of 74 mm Hg (range 10--190 mm Hg), which fell to a mean resting postoperative gradient of 8 mm Hg (range 0--25 mm Hg), was associated with decreased end-diastolic interventricular septal thickness at the midventricular level in 14 of 16 patients and at the subaortic level in 16 of 16 patients by M-mode echocardiography. The group also demonstrated changes in left ventricular outflow tract configuration and dimension, mitral valve systolic anterior motion, mitral E-F0 slope and left ventricular percent fractional shortening by both M-mode and two-dimensional studies. In the two patients who did not show midventricular septal thinning on M-mode echocardiography, the two-dimensional echocardiograms revealed that the area of myectomy extended only through the subaortic region and not down to the midventricular septum. Thus, we have observed consistent postmyectomy septal thinning at both the midventricular and subaortic levels by M-mode echo. By defining the geometry of the septal myectomy in vivo with two-dimensional echocardiography, we can better interpret M-mode studies and identify factors that influence echocardiographic visualization of the region of myectomy.
View details for Web of Science ID A1978FT99700012
View details for PubMedID 568040
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ECHOCARDIOGRAPHY-PERICARDIAL THICKENING AND CONSTRICTIVE PERICARDITIS
AMERICAN JOURNAL OF CARDIOLOGY
1978; 42 (3): 388-395
Abstract
A total of 167 patients with pericardial thickening noted on M node echocardiography were studied retrospectively. After the echocardiogram, 72 patients underwent cardiac surgery, cardiac catheterization or autopsy for various heart diseases; 96 patients had none of these procedures. In 49 patients the pericardium was directly visualized at surgery or autopsy; 76 percent of these had pericardial thickening or adhesions. In another 8 percent, pericardial adhesions were absent, but no comment had been made about the appearance of the pericardium itself. In the remaining 16 percent, no comment had been made about the pericardium or percardial space. Cardiac catheterization in 64 patients revealed 24 with hemodynamic findings of constrictive pericarditis or effusive constrictive disease. Seven echocardiographic patterns consistent with pericardial adhesions or pericardial thickening are described and related when possible to the subsequent findings at heart surgery or autopsy. The clinical diagnoses of 167 patients with pericardial thickening are presented. The hemodynamic diagnosis of constrictive pericardial disease was associated with the echocardiographic finding of pericardial thickening, but there were no consistent echocardiographic patterns of pericardial thickening diagnostic of constriction. However, certain other echocardiographic abnormalities of left ventricular posterior wall motion and interventricular septal motion and a high E-Fo slope were suggestive of constriction.
View details for Web of Science ID A1978FQ60000008
View details for PubMedID 685851
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CURRENT CONCEPTS IN CARDIOLOGY - ECHOCARDIOGRAPHIC EVALUATION OF LEFT-VENTRICULAR FUNCTION
NEW ENGLAND JOURNAL OF MEDICINE
1977; 296 (15): 856-858
View details for Web of Science ID A1977DB25800006
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ECHOCARDIOGRAPHIC DETECTION OF PERICARDIAL-EFFUSION AND PERICARDIAL THICKENING IN MALIGNANT-LYMPHOMA
RADIOLOGY
1977; 123 (1): 161-164
Abstract
Serial echocardiographic examinations of the heart were obtained for 13 patients undergoing irradiation for malignant lymphoma. Eleven of these had been shown to have mediastinal adenopathy; none had clinically detectable pericardial disease. The pericardial effusion which had been echocardiographically evident in 6 patients prior to treatment disappeared during or subsequent to the course of radiotherapy. Small asymptomatic effusions appeared in 5 patients during the follow-up period. Pericardial effusions, detected easily by echocardiography, occur more commonly than hed been previously thought in patients with malignant lymphoma.
View details for Web of Science ID A1977CZ41400034
View details for PubMedID 847144
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ASSESSMENT OF MITRAL-STENOSIS AND PROSTHETIC MITRAL-VALVE OBSTRUCTION, USING POSTERIOR AORTIC-WALL ECHOCARDIOGRAM
CIRCULATION
1977; 55 (6): 885-891
Abstract
The echocardiographic motion of the aortic root reflects, in part, left atrial filling and emptying. Patients with mitral valve obstruction were studied to determine whether clinically important alterations in patterns of left atrial emptying would alter motion of the posterior aortic wall. Patients with mitral stenosis had a characteristic pattern of slowing of left atrial emptying in early diastole, with loss of the conduit phase in mid-diastole. The atrial emptying index, defined as the fraction of passive posterior aortic wall motion occurring in the first third of diastole, was significantly related to the mitral valve area index (r = 0.86), and thus provides a noninvasive quantitation of the degree of mitral stenosis. Determination of the atrial emptying index also proved useful in the evaluation of patients with prosthetic mitral valve obstruction and in documenting improvement in left atrial emptying after mitral valve surgery.
View details for Web of Science ID A1977DG59900012
View details for PubMedID 870246
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MITRAL-VALVE PROLAPSE AND INFECTIVE ENDOCARDITIS
AMERICAN JOURNAL OF MEDICINE
1977; 63 (2): 215-222
View details for Web of Science ID A1977DR94700007
View details for PubMedID 888845
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Effect of transducer placement on echocardiographic mitral valve systolic motion.
European journal of cardiology
1976; 4 (3): 359-366
Abstract
The influence of transducer position and angulation upon the mitral systolic echo was studied in 100 presumably healthy females. Echocardiographic studies were performed from the second, third, fourth and fifth intercostal spaces (ICS). The role of the sound beam's path relative to cardiac motion was assessed by analyzing the recorded mitral valve pattern as a function of transducer orientation, independent of the absolute ICS used. With the transducer directed caudally when both mitral leaflets and left atrium were recorded, holosystolic or midsystolic posterior motion of the mitral valve leaflet echo was seen in 59% of the subjects. These patterns, recorded this way, were not related to phonocardiographic signs suggesting mitral valve prolapse. Best correlation with phonocardiographic findings was obtained when the echocardiographic examination was performed with the transducer either perpendicular to the chest in the sagittal plane, or pointing slightly cephalad ('perpendicular' position). With the transducer in 'perpendicular' position, both holosystolic and midsystolic posterior motion of the mitral systolic echo, deviating more than 2 mm from a line joining the C and D points, were highly related statistically to phonocardiographic findings suggesting mitral valve prolapse. This study demonstrates that transducer position and angulation on the chest wall are important determinants of echocardiographic appearance of mitral valve during systole. Only the 'perpendicular' transducer position should be used when analyzing echocardiograms for the presence of mitral valve prolapse.
View details for PubMedID 964284
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MITRAL-VALVE PROLAPSE SYNDROME
JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION
1976; 236 (7): 867-870
View details for Web of Science ID A1976CA63400032
View details for PubMedID 947271
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ECHOCARDIOGRAPHIC AND PHONOCARDIOGRAPHIC CONFIRMATION OF SUSPECTED CAGED MITRAL-VALVE MALFUNCTION
CHEST
1976; 70 (2): 221-230
Abstract
Seven patients studied by echocardiography with and without simultaneous phonocardiography for suspected malfunction of a caged mitral valve prosthesis are presented. In case 1, with inaudible prosthetic clicks, thrombosis of the cage and immobility of the ball were suggested by echocardiographic studies and confirmed at surgery. In case 2, simultaneous echocardiographic and phonocardiographic studies demonstrated wide and variable intervals between the aortic second sound the the opening click and also "sticking" of the ball. In case 3 a thrombus prevented full motion of the ball to the apex of the cage, which was seen on the echocardiogram, while in case 4, with a thrombus within the ventricle and prosthesis, the prosthetic opening click was present intermittently and was associated with only subtle echocardiographic changes. In case 5, echocardiographic studies demonstrated abnormal rocking of the cage secondary to severe prosthetic dehiscence. In case 6, dul prosthetic clicks were to be secondary to a low cardiac-output state. In case 7, with multiple valve prostheses, simultaneous echocardiographic and phonocardiographic studies allowed identification of individual valve sounds and abnormal timing of valve opening. Based on these studies, we believe that echocardiography and simultaneous phonocardiography can yield very useful information in the evaluation of patients with suspected malfunction of a caged mitral valve prosthesis.
View details for Web of Science ID A1976CA27300008
View details for PubMedID 947687
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ECHOCARDIOGRAPHIC EVALUATION OF PROPRANOLOL THERAPY FOR MITRAL-VALVE PROLAPSE
BRITISH HEART JOURNAL
1976; 38 (2): 129-134
Abstract
This study evaluates the effect of propranolol on the echocardiogram of 8 patients with late systolic mitral value prolapse. Echocardiograms were performed with the patients on no medication and again while on oral propranolol therapy. Propranolol caused a statistically significant increase in left ventricular volume; however, neither the echocardiographic pattern nor the timing of mitral valve prolapse was altered by propranolol. These findings suggest that factors in addition to left ventricular volume play a role in regulating valvular dysfunction in this condition.
View details for Web of Science ID A1976BH52500003
View details for PubMedID 1259827
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MITRAL-VALVE PROLAPSE IN 100 PRESUMABLY HEALTHY YOUNG FEMALES
CIRCULATION
1976; 53 (3): 464-473
Abstract
Clinical, electrocardiographic, phonocardiographic, and echocardiographic examinations were performed in 100 presumably healthy young females. Treadmill testing and ambulatory electrocardiographic monitoring were performed in a selected group of these subjects. Phonocardiograms, recorded with the subjects supine at rest, after inhalation of amyl nitrite, and in the upright position, revealed a 17% incidence of nonejection clicks and/or late or mid- to late systolic murmurs (PHONO-MSCLSM). Echocardiographic studies were performed in the second, third, fourth, and fifth intercostal space with emphasis on the importance of transducer angulation on the chest. Studies obtained with the transducer perpendicular to the chest in the sagittal plane, or pointing cephalad at a time when both mitral leaflets and left atrium are recorded, are optimal to study the mitral valve systolic motion. With the transducer in this position, 21 subjects were found to have pansystolic or late systolic prolapse, as previously defined on the echocardiogram. The presence of these echocardiographic findings was statistically related to the presence of PHONO-MSCLSM. Other echocardiographic patterns were identified and their relation to PHONO-MSCLSM and transducer position is discussed. Ten subjects with both echocardiographic evidence of mitral valve prolapse and PHONO-MSCLSM were identified (group EP), while 18 other subjects had either echocardiographic or phonocardiographic findings suggestive of mitral valve abnormality (group EorP). Seventy-two subjects had no abnormality (group noEP). The incidence of various clinical, electrocardiographic, and echocardiographic findings in these three groups was determined. Some findings said to be common in patients with proven mitral valve prolapse were seen more frequently in group EP subjects. Echocardiographic and phonocardiographic findings suggesting mitral valve abnormalities were found more commonly than expected in a population of presumably healthy young females.
View details for Web of Science ID A1976BG97200012
View details for PubMedID 1248078
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NONINVASIVE DIAGNOSIS OF COMPLICATIONS OF MITRAL BIOPROSTHESIS
JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
1976; 71 (3): 450-457
Abstract
The echophonocardiographic diagnoses of valvular and paravalvular insufficiency, calcific stenosis, and thrombolic occlusion of the stent-mounted aortic homograft or heterograft in the mitral position are described. Paravalvular and valvular insufficiency were associated with apical systolic murmurs which decreased in intensity after amyl nitrite inhalation and with echocardiograms which showed initial diastolic slopes of the stents in excess of the normal range (1.9 to 3.3 cm. per second). In clinically improved and stable patients, amyl nitrite inhalation resulted in increased intensity of the commonly heard systolic ejection type murmur at the left sternal border and echocardiographic evidence of further narrowing of the outflow tract measured between the interventricular septum and the anterior portion of the stent. Calcific homograpft stenosis was associated with a decreased diastolic stent slope (0.4 cm. per second) and increased echo density from the tissue leaflets. Thrombus formation on the sewing ring caused fatal inflow occlusion in 2 patients. The condition was characterized by an echocardiogram showing decreased ratio of internal-to-external stent diameter, 0.47 (normal range 0.56 to 0.74), decreased diastolic stent slope, and decreased leaflet excursion.
View details for Web of Science ID A1976BK05500023
View details for PubMedID 1249979
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LIFE-THREATENING ARRHYTHMIAS IN MITRAL-VALVE PROLAPSE SYNDROME
AMERICAN JOURNAL OF MEDICINE
1976; 60 (7): 961-967
Abstract
This study describes seven patients with the mitral valve prolapse or click-murmur syndrome who have survived one or more episodes of life-threatening ventricular arrhythmias. These arrhythmias include cardiac arrest due to ventricular fibrillation, recurrent ventricular tachycardia causing syncope or sustained ventricular tachycardia requiring electroversion. These patients were seen over a two-year period in a single medical center. Five of the seven had repolarization abnormalities in the resting electrocardiogram. Premature ventricular contractions were present in the routine resting electrocardiograms of six of the seven patients and were frequent during treadmill testing and ambulatory electrocardiographic monitoring in all six tested. There were electrolyte abnormalities or changes in medications known to affect myocardial repolarization during the week before the episode in three of the four patients with cardiac arrest. The diagnosis of mitral valve prolapse click-murmur syndrome was made prior to the episode of life-threatening arrhythmia in only two of the seven patients. Varying forms of antiarrhythmic therapy were given to these patients during follow-up periods of five to 26 months. Although the incidence of fatal arrhythmias in the mitral prolapse syndrome is probably small, we suggest that such arrhythmias may not be extremely rare, particularly among those patients who have repolarization abnormalities in the resting electrocardiogram and frequent premature beats. Patients with unexplained ventricular arrhythmias should be screened for mitral valve prolapse.
View details for Web of Science ID A1976BU68600006
View details for PubMedID 937357
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ECHOCARDIOGRAPHIC EVALUATION OF STENT MOUNTED AORTIC BIOPROSTHETIC VALVE IN MITRAL POSITION - INVITRO AND INVIVO STUDIES
CIRCULATION
1976; 54 (1): 91-96
Abstract
Echocardiograms were performed on 20 clinically stable patients following mitral valve replacement with glutaraldehyde-preserved porcine aortic heterografts and three patients with antibiotic sterilized aortic homografts mounted in the mitral position. Such valves were evaluated in a test chamber at varied flow rates resulting in improved understanding of movements seen with the echocardiogram in vivo. The technique for recording the valvular stent and leaflets is described and a method for measuring several parameters is demonstrated. Initial diastolic slope averaged 2.4 +/- 0.5 cm/sec (range 1.9 to 3.3 cm/sec). Left ventricular outflow tract measured from the anterior portion of the stent to the interventricular septum averaged 1.5 +/- 0.5 cm at end-diastole and 1.3 +/- 0.6 cm at end-systole. Leaflet excursion averaged 1.5 +/- 0.3 cm (with a range from 1.0 to 2.1 cm). The ratio of internal to external stent diameters averaged 0.66 +/- 0.05 (with a range from 0.56 to 0.74).
View details for Web of Science ID A1976BV45600015
View details for PubMedID 1277434
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POSTERIOR AORTIC-WALL ECHOCARDIOGRAM ITS RELATIONSHIP TO LEFT ATRIAL VOLUME CHANGE
CIRCULATION
1976; 54 (5): 744-750
Abstract
The normal posterior aortic wall echocardiogram shows anterior motion during left ventricular systole and predominantly posterior motion in three phases during left ventricular diastole. In six patients undergoing simultaneous left atrial angiograms and posterior aortic wall echocardiograms, there was excellent correlation between the posterior aortic wall motion and the change in the left atrial angiographic area showing the value of the posterior aortic wall echocardiogram in describing the left atrial volume curve. Left atrial and left ventricular pressures were measured with manometer tip catheters and correlated with simultaneous posterior aortic wall and mitral valve echocardiograms in four patients with atrial septal defects. These echocardiographic, angiographic, and hemodynamic correlations, as well as other evidence reported in this paper suggest that a major portion of posterior aortic wall motion is related to left atrial events and describes the left atrial volume curve.
View details for Web of Science ID A1976CJ65800007
View details for PubMedID 975469
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ECHOCARDIOGRAPHIC ASSESSMENT OF CARDIAC DISEASE
CIRCULATION
1976; 54 (4): 538-552
View details for Web of Science ID A1976CE72200003
View details for PubMedID 786497
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PHONOCARDIOGRAPHIC AND ECHOCARDIOGRAPHIC FEATURES OF RUPTURED AORTIC VALVULAR CUSP
CHEST
1976; 69 (5): 669-671
View details for Web of Science ID A1976BQ69700020
View details for PubMedID 1269278
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Report of the inter-Society Commission for Heart Disease Resources. Optimal resources for ultrasonic examination of the heart.
Journal of clinical ultrasound
1975; 3 (2): 145-151
Abstract
The echocardiographic examination is described and the current status of ultrasound in cardiac diagnosis is summarized. Planning guidelines are provided for hospital based echocardiography laboratories including resource criteria for professional personnel and training, equipment, space, and support systems. Minimal case loads for maintaining quality performance of the examiner are recommended and various administrative patterns for organizing an echocardiography service are discussed. Approaches for establishing professional fees and emerging applications of diagnostic ultrasound in cardiovascular medicine are briefly reviewed. There is a description of the procedure for conducting an adequate echocardiographic examination in children and adults.
View details for PubMedID 829505
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ECHOCARDIOGRAPHIC FEATURES OF SUPRAVALVULAR AORTIC-STENOSIS
CIRCULATION
1975; 52 (5): 817-822
Abstract
A method for the echocardiographic detection of supravalvular aortic stenosis (SVAS) is described and the findings in a series of patients are presented. When compared to angiography, the echo tended to underestimate the severity of the supravalvular aortic obstruction. However, echocardiography appears to be a valuable, noninvasive method for detecting SVAS.
View details for Web of Science ID A1975AT26800010
View details for PubMedID 1175262
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DIAGNOSTIC ACCURACY OF AN ULTRASONIC MULTIPLE TRANSDUCER CARDIAC IMAGING SYSTEM
AMERICAN HEART JOURNAL
1975; 90 (3): 329-334
Abstract
Eighty patients with various forms of heart disease were studied with the use of a newly developed ultrasonic system having 20 transducers arranged in a linear array. This system allows visualization of the heart in two dimensions in real time. All 15 patients with the mitral valve prolapse syndrome, 13 patients with mitral stenosis, five patients with pericardial effusion, four patients with atrial septal defect, and one patient with left ventricular dyssynergy were properly recognized with this system. One of five patients with hypertrophic myopathy and one of four patients with congestive myopathy were not recognized with this system. Criteria for the recognition of these system. Criteria for the recognition of these conditions are presented as well as the probable cause for false-positive and false-negative diagnoses in this series. Since only qualitative criteria were used, it was not possible to differentiate patients with coronary artery disease or patients with left ventricular volume overload from patients without cardiac pathology. The accuracy of this new system was judged against the clinical examination, conventional echocardiography, cardiac catheterization, and left ventricular angiography. It is assumed that the criteria for diagnosis developed during this study will be supplemented and the equipment improved in the future; however, the ease of operation of this system and the relative accuracy of diagnosis at this stage of its development are extremely interesting. It presents an excellent opportunity to obtain additional information about the cardiac patient without using invasive procedures and without risk.
View details for Web of Science ID A1975AN58400008
View details for PubMedID 126012
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EFFECT OF TRANSDUCER PLACEMENT ON ECHOCARDIOGRAPHIC MEASUREMENT OF LEFT-VENTRICULAR DIMENSIONS
AMERICAN JOURNAL OF CARDIOLOGY
1975; 35 (4): 537-540
Abstract
An echocardiogram from the left ventricle may be used to estimate left ventricular volume and rate of circumferential fiber shortening, to measure posterior wall and interventricular septal thickness and to evaluate the normality of septal motion. Extended application of this technique in this laboratory has emphasized the need for a more standardized means of transducer location and direction. The effect of placing the ultrasonic transducer in several intercostal spaces along the left sternal border was tested in 14 patients. Variability in the left ventricular dimension and the difference in this dimension from end-diastole to end-systole were greater than for duplicate measurements from the same interspace. A system has been developed for more consistent placement of the transducer in each patient, using intracardiac landmarks and observation of transducer orientation to record specific cardiac structures.
View details for Web of Science ID A1975W105600011
View details for PubMedID 1119405
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ECHOCARDIOGRAPHIC CRITERIA FOR AORTIC ROOT DISSECTION
AMERICAN JOURNAL OF CARDIOLOGY
1975; 36 (1): 17-20
Abstract
Echocardiographic findings from 10 patients without clinical indications of aortic root dissection or aortic valve disease from 1 patient with angiographic confirmation of aortic root dissection are reported and compared. Previously reported echocardiographic findings were confirmed in the patient with aortic root dissection. These include (1) a widened posterior or anterior aortic wall, or both; (2) parallel motion of the separated margins of the aortic walls; and (3) aortic root dilatation (42 mm or more at end-systole). However, all three findings were also noted in 5 of the 10 patients without clinical indications of aortic root dissection or aortic valve disease, and at least two of the three findings were noted in the remaining 5 patients. Echocardiographic detection of aortic root dissection appears to be most reliable when clinical indications of the anomaly are present.
View details for Web of Science ID A1975AH58200003
View details for PubMedID 1146693
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SIMULTANEOUS ECHOCARDIOGRAPHIC-PHONOCARDIOGRAPHIC RECORDINGS AT REST AND DURING AMYL NITRITE ADMINISTRATION IN PATIENTS WITH MITRAL-VALVE PROLAPSE
CIRCULATION
1975; 51 (3): 522-529
Abstract
Simultaneous electrocardiograms, phonocardiograms, and echocardiograms were recorded in 21 patients with mitral valve prolapse. Four patients with holosystolic mitral valve prolapse on echocardiogram had smaller resting end-diastolic volumes than the remaining 17 patients with late systolic echocardiopraphy prolapse (p greater than 0.01). Thirteen of the 17 patients with late systolic prolapse had phonocardiograhically recorded auscultatory phenomena. The initial vibrations of the auscultatory phenomena occurred after the onset of echocardiographic prolapse, but prior to maximal echocardiographic mitral valve prolapse. Amyl nitrite was administered to all patients. Three of the 17 patients with late systolic prolapse developed holosystolic prolapse, while the remaining 14 retained the late systolic prolapse pattern during amyl nitrite inhalation. In these 14 patients, the onset of mitral prolapse occurred earlier in systole due to decrease in the duration of systole prior to onset of mitral valve prolapse (p greater than 0.001). This corresponded with the occurrence of auscultatory phenomena earlier in systole. Twelve patients had left ventricular volumes recorded during amyl nitrite inhalation and all showed a decrease in left ventricular volumes (greater than) 0.001). These findings confirm the temporal relationship of mitral valve prolapse and onset of auscultatory phenomena in these patients. It suggests that the movement of auscultatory phenomena earlier in systole during amyl nitrite inhalation is related to earlier prolapse of the mitral valve, and that a decrease in ventricular valume is a tenable explanation for the earlier onset of prolapse.
View details for Web of Science ID A1975V711600019
View details for PubMedID 1139761
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OPTIMAL RESOURCES FOR ULTRASONIC EXAMINATION OF HEART
AMERICAN JOURNAL OF CARDIOLOGY
1975; 35 (6): 898-903
View details for Web of Science ID A1975AE53700017
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VARIABILITY OF ECHOCARDIOGRAPHIC DISCONTINUITY IN DOUBLE OUTLET RIGHT VENTRICLE AND TRUNCUS ARTERIOSUS
CIRCULATION
1975; 51 (5): 848-854
Abstract
The widespread application of echocardiography to the field of congenital heart disease has led to the development of a concept of "echocardiographic discontinuity" for the diagnosis of some conditions. Although this is a valuable sign in differentiating such entities as tetralogy of Fallot, truncus arteriosus and double outlet right ventricle, the reported cases illustrate that the echocardiographic recognition of discontinuity may be complicated by technical factors. In addition, the differential diagnosis must include truncus arteriosus with coexistence of anterior and posterior discontinuity.
View details for Web of Science ID A1975AA03800012
View details for PubMedID 1122589
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Echocardiographic pseudo idiopathic hypertrophic subaortic stenosis.
Chest
1974; 66 (5): 573-574
View details for PubMedID 4473322
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NONINVASIVE LEFT VENTRICULOGRAM
NEW ENGLAND JOURNAL OF MEDICINE
1974; 291 (23): 1254-1255
View details for Web of Science ID A1974U819500014
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SOUND IN CARDIAC DIAGNOSIS
TERAPEVTICHESKII ARKHIV
1974; 46 (6): 128-135
View details for Web of Science ID A1974T693700023
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ILLUSTRATIVE ECHOCARDIOGRAM - ECHOCARDIOGRAPHIC PSEUDO IDIOPATHIC HYPERTROPHIC SUBAORTIC STENOSIS
CHEST
1974; 66 (5): 573-574
View details for Web of Science ID A1974U376900025
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[Use of ultrasonics in the diagnosis of heart diseases].
Terapevticheskii arkhiv
1974; 46 (6): 128-135
View details for PubMedID 4610874
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IMPROVED METHOD FOR ECHOGRAPHIC DETECTION OF LEFT ATRIAL ENLARGEMENT
CIRCULATION
1974; 50 (1): 58-64
View details for Web of Science ID A1974T610500010
View details for PubMedID 4276017
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ECHOCARDIOGRAPHIC CRITERIA IN DIAGNOSIS OF IDIOPATHIC HYPERTROPHIC SUBAORTIC STENOSIS
CIRCULATION
1974; 50 (4): 747-751
View details for Web of Science ID A1974U467100016
View details for PubMedID 4278516
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ECHOCARDIOGRAPHIC FINDINGS IN DISCRETE SUBVALVULAR AORTIC-STENOSIS
CIRCULATION
1974; 49 (2): 226-231
View details for Web of Science ID A1974S094200004
View details for PubMedID 4855729
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CORONARY-ARTERY DISEASE WITH IDIOPATHIC HYPERTROPHIC SUBAORTIC STENOSIS
LANCET
1974; 1 (7863): 901-903
View details for Web of Science ID A1974S944000006
View details for PubMedID 4133421
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VENTRICULAR SYSTOLIC SEPTAL THICKENING AND EXCURSION IN IDIOPATHIC HYPERTROPHIC SUBAORTIC STENOSIS
NEW ENGLAND JOURNAL OF MEDICINE
1974; 291 (25): 1317-1319
View details for Web of Science ID A1974V010300001
View details for PubMedID 4473712
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ECHOCARDIOGRAPHIC ABNORMALITIES IN MITRAL-VALVE PROLAPSE SYNDROME
CIRCULATION
1974; 49 (3): 428-433
View details for Web of Science ID A1974S351000010
View details for PubMedID 4813176
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COMPUTER-PROCESSING OF ULTRASONIC DATA FROM CARDIOVASCULAR-SYSTEM
COMPUTERS AND BIOMEDICAL RESEARCH
1973; 6 (4): 336-346
View details for Web of Science ID A1973Q621800004
View details for PubMedID 4582625
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ULTRASONIC STUDIES FOR EARLY DETECTION OF ACUTE CARDIAC REJECTION
TRANSPLANTATION
1971; 11 (6): 543-?
View details for Web of Science ID A1971J597000007
View details for PubMedID 4931455