Professional Education

  • Doctor of Philosophy, Linkoping University (2016)
  • Doctor of Medicine, Linkoping University (2012)
  • Bachelor of Science, Linkoping University (2009)

Stanford Advisors

All Publications

  • From guidelines to the sidelines: implementation of cardiovascular preparticipation evaluation in sports clubs is lagging. British journal of sports medicine Hedman, K., Sunnerud, S., Carlén, A., Janzon, M., Nylander, E. 2018

    View details for DOI 10.1136/bjsports-2018-099297

    View details for PubMedID 29921655

  • Vascular characteristics in young women-Effect of extensive endurance training or a sedentary lifestyle. Acta physiologica (Oxford, England) Bjarnegård, N., Länne, T., Cinthio, M., Ekstrand, J., Hedman, K., Nylander, E., Henriksson, J. 2018; 223 (2): e13041


    To explore whether high-level endurance training in early age has an influence on the arterial wall properties in young women.Forty-seven athletes (ATH) and 52 controls (CTR), all 17-25 years of age, were further divided into runners (RUN), whole-body endurance athletes (WBA), sedentary controls (SC) and normally active controls (AC). Two-dimensional ultrasound scanning of the carotid arteries was conducted to determine local common carotid artery (CCA) geometry and wall distensibility. Pulse waves were recorded with a tonometer to determine regional pulse wave velocity (PWV) and pulse pressure waveform.Carotid-radial PWV was lower in WBA than in RUN (P < .05), indicating higher arterial distensibility along the arm. Mean arterial pressure was lower in ATH than in CTR and in RUN than in WBA (P < .05). Synthesized aortic augmentation index (AI@75) was lower among ATH than among CTR (-12.8 ± 1.6 vs -2.6 ± 1.2%, P < .001) and in WBA than in RUN (-16.4 ± 2.5 vs -10.7 ± 2.0%, P < .05), suggesting a diminished return of reflection waves to the aorta during systole. Carotid-femoral PWV and intima-media thickness (IMT), lumen diameter and radial distensibility of the CCA were similar in ATH and CTR.Elastic artery distensibility and carotid artery IMT are not different in young women with extensive endurance training over several years and in those with sedentary lifestyle. On the other hand, our data suggest that long-term endurance training is associated with potentially favourable peripheral artery adaptation, especially in sports where upper body work is added. This adaptation, if persisting later in life, could contribute to lower cardiovascular risk.

    View details for DOI 10.1111/apha.13041

    View details for PubMedID 29359513

  • Lakartidningen Sunnerud, S., Nylander, E., Janzon, M., Carlén, A., Hedman, K. 2018; 115


    Low adherence to recommended pre-participation cardiac evaluation of Swedish athletes Pre-participation cardiac evaluation of athletes is recommended by international organizations like the European Society of Cardiology and the American Heart Association, as well as by the Swedish Sports Confederation. The purpose of the evaluation is to prevent sudden cardiac death in athletes by early identification of individuals at risk. To our knowledge, no previous study has been made regarding the implementation of pre-participation cardiac evaluation of athletes in Sweden. We performed an electronical survey addressing sports clubs in one out of 21 districts in which the Swedish Sports Confederation is geographically divided. Only four out of 22 responding clubs with elite athletes preformed cardiac evaluation. Lack of knowledge about the recommendations as well as how to perform the evaluation were mentioned as reasons not to evaluate the athletes. Our results indicate the need for more information about pre-participation cardiac evaluation of athletes in Sweden.

    View details for PubMedID 29381184

  • Left Ventricular Adaptation to 12 Weeks of Indoor Cycling at the Gym in Untrained Females. International journal of sports medicine Hedman, K., Bjarnegård, N., Länne, T. 2017; 38 (9): 653–58


    Cross-sectional studies provide evidence of larger cardiac dimensions and mass in endurance trained than in untrained females. Much less is known regarding adaptations in cardiac function following training in untrained subjects. We aimed to study left ventricular (LV) adaptation to indoor cycling in previously untrained females, in regard of LV dimensions, mass and function. 42 sedentary females were divided into 2 equally sized groups, either training indoor cycling at regular classes at a local gym for 12 weeks, in average 2.6 times per week, or maintaining their sedentary lifestyle. Echocardiography at rest and a maximal exercise test were performed before and after the intervention. Exercise capacity increased in average 16% in the exercise group (p<0.001), together with decreased heart rate at rest (p<0.05) and at 120 watts steady-state (p<0.001). There were no difference in systolic or diastolic function following the intervention and minimal increases in LV internal diameter in diastole (+1 mm, p<0.01). LV mass was unchanged with training (137±25 vs. 137±28 g, p=0.911). Our findings indicate that attending indoor cycling classes at a gym 2-to-3 times per week for 12 weeks is enough to improve exercise capacity, while a higher volume of training is required to elicit cardiac adaptations.

    View details for DOI 10.1055/s-0043-112341

    View details for PubMedID 28704880



    The aim of the study was to explore the long- and short-axis dimensions, shape and collapsibility of the inferior vena cava in 46 trained and 48 untrained females (mean age: 21 ± 2 y). Echocardiography in the subcostal view revealed a larger expiratory long-axis diameter (mean: 24 ± 3 vs. 20 ± 3 mm, p < 0.001) and short-axis area (mean: 5.5 ± 1.5 vs. 4.7 ± 1.4 cm2, p = 0.014) in trained females. IVC shape (the ratio of short-axis major to minor diameters) and the relative decrease in IVC dimension with inspiration were similar for the two groups. The IVC long-axis diameter reflected short-axis minor diameter and was correlated to maximal oxygen uptake (r = 0.52, p < 0.01). In summary, the results indicate that trained females have a larger IVC similar in shape and respiratory decrease in dimensions to that of untrained females. The long-axis diameter corresponded closely to short-axis minor diameter and, thus, underestimates maximal IVC diameter.

    View details for DOI 10.1016/j.ultrasmedbio.2016.07.003

    View details for Web of Science ID 000389549300008

    View details for PubMedID 27623502

  • Female athlete's heart: Systolic and diastolic function related to circulatory dimensions SCANDINAVIAN JOURNAL OF MEDICINE & SCIENCE IN SPORTS Hedman, K., Tamas, E., Henriksson, J., Bjarnegard, N., Brudin, L., Nylander, E. 2015; 25 (3): 372-381


    There are relatively few studies on female athletes examining cardiac size and function and how these measures relate to maximal oxygen uptake (VO2max). When determining sports eligibility, it is important to know what physiological adaptations and characteristics may be expected in female athletes, taking body and cardiac size into account. The purposes of this study were (a) to compare right and left heart dimensions and function in female endurance athletes (ATH) and in non-athletic female controls of similar age (CON); and (b) to explore how these measures related to VO2max. Forty-six ATH and 48 CON underwent a maximal bicycle exercise test and an echocardiographic examination at rest, including standard and color tissue Doppler investigation. All heart dimensions indexed for body size were larger in ATH (all P < 0.01). The diastolic mitral E/A ratio was 27% higher in ATH (P < 0.001) while systolic left and right atrio-ventricular longitudinal displacement was 7% (P = 0.002) and 15% (P < 0.001) larger in ATH, respectively. Half (50.3%) of the variability in VO2max could be explained by left ventricular end-diastolic volume. Our results could be useful in evaluating female endurance athletes with suspected cardiac disease and contribute to understanding differences between female athletes and non-athletes.

    View details for DOI 10.1111/sms.12246

    View details for Web of Science ID 000354568800021

    View details for PubMedID 24840312

  • Cardiac systolic regional function and synchrony in endurance trained and untrained females. BMJ open sport & exercise medicine Hedman, K., Tamás, É., Bjarnegård, N., Brudin, L., Nylander, E. 2015; 1 (1)


    Most studies on cardiac function in athletes describe overall heart function in predominately male participants. We aimed to compare segmental, regional and overall myocardial function and synchrony in female endurance athletes (ATH) and in age-matched sedentary females (CON).In 46 ATH and 48 CON, echocardiography was used to measure peak longitudinal systolic strain and myocardial velocities in 12 left ventricular (LV) and 2 right ventricular (RV) segments. Regional and overall systolic function were calculated together with four indices of dyssynchrony.There were no differences in regional or overall LV systolic function between groups, or in any of the four dyssynchrony indices. Peak systolic velocity (s') was higher in the RV of ATH than in CON (9.7±1.5 vs 8.7±1.5 cm/s, p=0.004), but not after indexing by cardiac length (p=0.331). Strain was similar in ATH and CON in 8 of 12 LV myocardial segments. In septum and anteroseptum, basal and mid-ventricular s' was 6-7% and 17-19% higher in ATH than in CON (p<0.05), respectively, while s' was 12% higher in CON in the basal LV lateral wall (p=0.013). After indexing by cardiac length, s' was only higher in ATH in the mid-ventricular septum (p=0.041).We found differences between trained and untrained females in segmental systolic myocardial function, but not in global measures of systolic function, including cardiac synchrony. These findings give new insights into cardiac adaptation to endurance training and could also be of use for sports cardiologists evaluating female athletes.

    View details for PubMedID 27900120

    View details for PubMedCentralID PMC5117015

  • Decreased aerobic capacity 4 years after aortic valve replacement in male patients operated upon for chronic aortic regurgitation CLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING Hedman, K., Tamas, E., Nylander, E. 2012; 32 (3): 167-171


    Exercise testing is underutilized in patients with valve disease. We have previously found a low physical work capacity in patients with aortic regurgitation 6 months after aortic valve replacement (AVR). The aim of this study was to evaluate aerobic capacity in patients 4 years after AVR, to study how their peak oxygen uptake (peakVO(2)) had changed postoperatively over a longer period of time. Twenty-one patients (all men, 52±13 years) who had previously undergone cardiopulmonary exercise testing (CPET) pre- and 6 months postoperatively underwent maximal exercise testing 49 ± 15 months postoperatively using an electrically braked bicycle ergometer. Breathing gases were analysed and the patients' physical fitness levels categorized according to Åstrand's and Wasserman's classifications. Mean peakVO(2) was 22·8 ± 5·1 ml × kg(-1) × min(-1) at the 49-month follow-up, which was lower than at the 6-month follow-up (25·6 ± 5·8 ml × kg(-1) × min(-1), P = 0·001). All but one patient presented with a physical fitness level below average using Åstrand's classification, while 13 patients had a low physical capacity according to Wasserman's classification. A significant decrease in peakVO(2) was observed from six to 49 months postoperatively, and the decrease was larger than expected from the increased age of the patients. CPET could be helpful in timing aortic valve surgery and for the evaluation of need of physical activity as part of a rehabilitation programme.

    View details for DOI 10.1111/j.1475-097X.2011.01072.x

    View details for Web of Science ID 000302545300001

    View details for PubMedID 22487149

    View details for PubMedCentralID PMC3489036