Electrocardiographic and echocardiographic characteristics of female athletes

This study examined electrocardiographic and echocardiographic characteristics of endurance- and resistance-trained female athletes. The subjects were 10 varsity caliber endurance-trained athletes, 10 resistance-trained athletes, and 10 nonathletes. Data collection included anthropometric measurements, VO2max, standard 12-lead ECGs and left ventricular dimensions measured by M-mode and two-dimensional echocardiography. For endurance-trained athletes, absolute left ventricular end-diastolic volume and values normalized for lean body mass were significantly greater than in nonathletes. An interstudy comparison of female vs male endurance-trained athletes from the same population also revealed significantly lower values for M-mode left ventricular mass expressed per kilogram of lean body mass in the former. Absolute and normalized wall thicknesses were not significantly greater in resistance-trained athletes compared to the other two groups. Wall thickness indexed for lean body mass was similar for the three groups. Sinus bradycardia was observed in all endurance athletes and in four resistance-trained athletes. ECG criteria were unreliable for the prediction of left ventricular enlargement. It appears that both female resistance- and endurance-trained athletes exhibit a lesser degree of enlargement of left ventricular wall thickness and mass than male athletes. A close relationship between skeletal and cardiac muscularity in resistance-trained athletes of both genders also was supported.