Honors & Awards
Outstanding Research Poster Award, Stanford Cardiovascular Institute (Oct 20, 2016)
B of Medicine and B of Surgery, Maharashtra University of Health Sciences (2012)
Long-Term Prognosis of Early Repolarization With J-Wave and QRS Slur Patterns on the Resting Electrocardiogram: A Cohort Study.
Annals of internal medicine
2015; 163 (10): 747-755
The prognostic value of early repolarization with J waves and QRS slurs remains controversial. Although these findings are more prevalent in patients with idiopathic ventricular fibrillation, their ability to predict cardiovascular death has varied across studies.To test the hypothesis that J waves and QRS slurs on electrocardiograms (ECGs) are associated with increased risk for cardiovascular death.Retrospective cohort.Veterans Affairs Palo Alto Health Care System.Veterans younger than 56 years who had resting 12-lead electrocardiography, 90.5% of whom were men.Electrocardiograms were manually measured and visually coded using criteria of 0.1 mV or greater in at least 2 contiguous leads. J waves were measured at the peak of an upward deflection or notch at the end of QRS, and QRS slurs were measured at the top of conduction delay on the QRS downstroke. Absolute risk differences at 10 years were calculated to study the associations between J waves or QRS slurs and the primary outcome of cardiovascular death.Over a median follow-up of 17.5 years, 859 cardiovascular deaths occurred. Of 20 661 ECGs, 4219 (20%) had J waves or QRS slurs in the inferior and/or lateral territories; of these, 3318 (78.6%) had J waves or QRS slurs in inferior leads and 1701 (40.3%) in lateral leads. The upper bound of differences in risk for cardiovascular death from any of the J-wave or QRS slur patterns suggests that an increased risk can be safely ruled out (inferior, -0.77% [95% CI, -1.27% to -0.27%]; lateral, -1.07% [CI, -1.72% to -0.43%]).The study consisted of predominantly men, and deaths could be classified as cardiovascular but not arrhythmic.J waves and QRS slurs did not exhibit a clinically meaningful increased risk for cardiovascular death in long-term follow-up.None.
View details for DOI 10.7326/M15-0598
View details for PubMedID 26501238
Surgical Unroofing of Hemodynamically Significant Left Anterior Descending Myocardial Bridges.
Annals of thoracic surgery
Left anterior descending artery myocardial bridges (MBs) range from clinically insignificant incidental angiographic findings to a potential cause of sudden cardiac death. Within this spectrum, a group of patients with isolated, symptomatic, and hemodynamically significant MBs despite maximally tolerated medical therapy exist for whom the optimal treatment is controversial. We evaluated supraarterial myotomy, or surgical unroofing, of the left anterior descending MBs as an isolated procedure in these patients.In 50 adult patients, we prospectively evaluated baseline clinical characteristics, risk factors, and medications for coronary artery disease, relevant diagnostic data (stress echocardiography, computed tomography angiography, stress coronary angiogram with dobutamine challenge for measurement of diastolic fractional flow reserve, and intravascular ultrasonography), and anginal symptoms using the Seattle Angina Questionnaire. These patients then underwent surgical unroofing of their left anterior descending artery MBs followed by readministration of the Seattle Angina Questionnaire at 6.6-month (range, 2 to 13) follow-up after surgery.Dramatic improvements were noted in physical limitation due to angina (52.0 versus 87.1, p < 0.001), anginal stability (29.6 versus 66.4, p < 0.001), anginal frequency (52.1 versus 84.7, p < 0.001), treatment satisfaction (76.1 versus 93.9, p < 0.001), and quality of life (25.0 versus 78.9, p < 0.001), all five dimensions of the Seattle Angina Questionnaire. There were no major complications or deaths.Surgical unroofing of carefully selected patients with MBs can be performed safely as an independent procedure with significant improvement in symptoms postoperatively. It is the optimal treatment for isolated, symptomatic, and hemodynamically significant MBs resistant to maximally tolerated medical therapy.
View details for DOI 10.1016/j.athoracsur.2016.08.035
View details for PubMedID 27745841
Effect of Sex Differences on Invasive Measures of Coronary Microvascular Dysfunction in Patients With Angina in the Absence of Obstructive Coronary Artery Disease
2015; 8 (11): 1433-1441
This study investigated sex differences in coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) in patients with angina in the absence of obstructive coronary artery disease.Coronary microvascular dysfunction is associated with worse long-term outcomes, especially in women. Coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR) are 2 methods of assessing the coronary microcirculation.We prospectively enrolled 117 women and 40 men with angina in the absence of obstructive coronary artery disease. We performed CFR, IMR, fractional flow reserve, and quantitative coronary angiography in the left anterior descending artery. Coronary flow was assessed with a thermodilution method by obtaining mean transit time (Tmn) (an inverse correlate to absolute flow) at rest and hyperemia.All patients had minimal atherosclerosis by quantitative coronary angiography (% diameter stenosis: 23.2 ± 12.3%), and epicardial disease was milder in women (fractional flow reserve: 0.88 ± 0.04 vs. 0.87 ± 0.04; p = 0.04). IMR was similar between the sexes (20.7 ± 9.8 vs. 19.1 ± 8.0; p = 0.45), but CFR was lower in women (3.8 ± 1.6 vs. 4.8 ± 1.9; p = 0.004). This was primarily due to a shorter resting Tmn in women (p = 0.005), suggesting increased resting coronary flow, whereas hyperemic Tmn was identical (p = 0.79). In multivariable analysis, female sex was an independent predictor of lower CFR and shorter resting Tmn.Despite similar microvascular function in women and men by IMR, CFR is lower in women. This discrepancy appears to be due to differences in resting coronary flow between the sexes. The effect of sex differences should be considered in interpretation of physiological indexes using resting coronary flow.
View details for DOI 10.1016/j.jcin.2015.03.045
View details for Web of Science ID 000361757600013
Examining QRS amplitude criteria for electrocardiographic left ventricular hypertrophy in recommendations for screening criteria in athletes.
Journal of electrocardiology
2015; 48 (3): 368-372
Current guidelines for interpretation of the ECGs of athletes recommend that isolated R and S wave amplitudes that exceed traditional criteria for left ventricular hypertrophy be accepted as a physiological response to exercise training. This is based on training and echocardiographic studies but not on long term follow up. Demonstration of the prognostic characteristics of the amplitude criteria in a non-athletic population could support the current guidelines.To evaluate the prognostic value of the R and S wave voltage criteria for electrocardiographic left ventricular hypertrophy (ECG-LVH) in an ambulatory clinical population.The target population consisted of 20,903 ambulatory subjects who had ECGs recorded between 1987 and 1999 and were followed for cardiovascular death until 2013. During the mean follow up of 17years, there were 881 cardiovascular deaths.The mean age was 43±10, 91% were male and 16% were African American. Of the 2482 (12%) subjects who met the Sokolow-Lyon criteria, 241 (1.2%) subjects with left ventricular (LV) strain had an HR of 5.4 (95% CI 4.1-7.2, p<0.001), while 2241 (11%) subjects without strain had an HR of 1.4 (95% CI 1.2-1.8, p<0.001). Of the 4836 (23%) subjects who met the Framingham voltage criteria, 350 (2%) subjects with LV strain had an HR of 5.1 (95% CI 4.0-6.5, p<0.001), while 4486 (22%) subjects without strain had an HR of 1.1 (95% CI 0.9-1.3, p=0.26). The individual components of the Romhilt-Estes had HRs ranging from 1.4 to 3.6, with only the voltage component not being significant (HR 1.1, 95% CI 0.9-1.5, p=0.35).This study demonstrates that the R and S wave voltage criteria components of most of the original classification schema for electrocardiographic left ventricular hypertrophy are not predictive of CV mortality. Our findings support the current guidelines for electrocardiographic screening of athletes.
View details for DOI 10.1016/j.jelectrocard.2014.12.012
View details for PubMedID 25661864
A New Electrocardiographic Left Ventricular Hypertrophy Prognostic Score
AMERICAN JOURNAL OF CARDIOLOGY
2015; 115 (7): 982-985
This report determines if the classic Romhilt-Estes score would predict better if points for its components were determined using a Cox hazard model and if the Cornell voltage criteria should replace the original criteria. Of the 20,903 subjects, the mean age was 43 ± 10 years and 90.6% were men. The mean follow-up for the population was 17 years, with 881 cardiovascular deaths; they were tested from 1987 to 1999 and followed until 2013. The new score was created with multipliers based on the Cox hazards of its elements with age bracket and gender included. The Cornell criteria were analyzed individually using Cox hazards with and without adjustments for age, gender, and African-American ethnicity and subsequently incorporated into the new score for analysis. For the new score, all 7 components were significant predictors of cardiovascular mortality with gender producing the greatest hazard ratio (HR) and left axis deviation and QRS duration >110 ms producing the lowest. For the original Romhilt-Estes score, 367 patients (1.8%) met the "definite" cutoff and had an HR of 5.6 (95% confidence interval 4.3 to 7.1). For the new score, 208 patients (1.0%) met the "definite" left ventricular hypertrophy cutoff and had an HR of 13.6 (95% confidence interval 10.8 to 17.3). The Romhilt-Estes had an area under the curve of 0.63, whereas the new score and new score with Cornell voltage both had an area under the curve of 0.7. In conclusion, our modified Romhilt-Estes score with new multipliers and without voltage criteria outperformed the original score.
View details for DOI 10.1016/j.amjcard.2015.01.028
View details for Web of Science ID 000352253000022
View details for PubMedID 25700803