Angiotensinogen gene M235T polymorphism predicts left ventricular hypertrophy in endurance athletes.

OBJECTIVES: We studied whether left ventricular mass in athletes associates with polymorphisms in genes encoding components of the renin-angiotensin system. BACKGROUND: Adaptive left ventricular hypertrophy is a feature of the athlete's heart. However, similarly training athletes develop left ventricular mass to a different extent, suggesting that genetic factors may modulate heart size. METHODS: We measured left ventricular mass by echocardiography in 50 male and 30 female elite endurance athletes aged 25 +/- 4 (mean +/- SD) years. Deoxyribonucleic acid samples were prepared for genotyping of angiotensinogen (AGT) gene M235T polymorphism, angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and angiotensin II type 1 receptor (AT1) gene A1166C polymorphism. RESULTS: The AGT gene M235T genotypes were significantly associated with left ventricular mass independently of blood pressure in both genders (p = 0.0036 for pooled data). TT homozygotes had greater mass compared with MM homozygotes in both men (147 +/- 12 g/m vs. 132 +/- 15 g/m, p = 0.032) and women (121 +/- 12 g/m vs. 101 +/- 13 g/m, p = 0.019). There was a gender difference in the relation between myocardial mass and AGT genotype, MT heterozygotes resembling MM homozygotes among women and TT homozygotes among men. The other studied gene polymorphisms were not associated with left ventricular mass. CONCLUSIONS: Angiotensinogen gene M235T polymorphism is associated with the variability in left ventricular hypertrophy induced by endurance training, with athletes homozygous for the T allele having the largest hearts. We found no association between ACE gene I/D or AT1 gene A1166C polymorphisms and left ventricular mass.

QT interval and QT dispersion in endurance athletes and in power athletes using large doses of anabolic steroids.

We measured electrocardiographic repolarization indexes in athletes. Physiologic adaptive cardiac hypertrophy did not increase QT dispersion in endurance athletes despite long QT intervals due to increased vagal tone. In contrast, power athletes taking large doses of anabolic steroids had increased QT dispersion despite short QT intervals, which seems to reflect altered myocardium in the hypertrophied heart.

Electrocardiographic findings in female endurance athletes.

OBJECTIVE: To determine the prevalence of aberrations in the resting electrocardiogram (ECG) in female athletes. DESIGN: Case-control study. PARTICIPANTS: Thirty female endurance athletes and 30 age-matched nonobese nonathletic control subjects. MAIN OUTCOME MEASURES: Different measurements based on resting ECGs. MAIN RESULTS: The athletes had lower heart rate (mean 53 +/- SD 7) than the controls (67 +/- 11; p < 0.0001), but no group difference was found in atrioventricular conduction (PQ interval). Cornell voltage (RaVl + SV3) reflecting left ventricular mass was higher in athletes (1.18 +/- 0.58 mV vs. 0.78 +/- 0.41 mV; p = 0.0030), but the deviations from normal limits were small. The index reflecting right ventricular mass (RV1 + SV5) was higher in athletes (0.58 +/- 0.23 mV) than controls (0.45 +/- 0.23 mV; P = 0.036) but did not exceed the criterion for right side hypertrophy. QRS duration was slightly prolonged in athletes (99 +/- 10 ms vs. 92 +/- 9 ms; p = 0.010), as were rate-adjusted QT intervals (p < 0.05). J-point elevations (p = 0.0062) and ST-segment elevations (p = 0.013) were seen more frequently in athletes, but were usually small. CONCLUSIONS: The female athlete's ECG differs less from control subjects than has been reported in male athletes. Extrathoracal anatomic considerations may explain some of the sex differences. However, when clear-cut ECG abnormalities are observed in female athletes, organic heart disease must be carefully excluded.

Left ventricular mass, geometry and filling in elite female and male endurance athletes.

We compared echocardiographic findings in female (n=30) and male (n=30) endurance athletes to age-matched female (n=15) and male (n=15) sedentary controls. The differences between athletes and controls were similar in both sexes; only left ventricular (LV) mass and septum thickness differed slightly more in men than in women (67% vs 55%, P=0.004, and 36% vs 30%, P=0.03, respectively). LV wall thicknesses were in the normal range in all women, while four (13%) male athletes exceeded 13 mm. In conclusion, the effects of endurance training on echocardiographic findings appear to be quite similar in women and men. However, in female athletes with an abnormally thick left ventricular wall a thorough cardiac evaluation is indicated. This contrasts with male athletes, in whom LV wall thicknesses of over 13 mm are a not uncommon finding.