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Left ventricular wall tension and stress during exercise in athletes and sedentary men
J R Schairer1, S Keteyian, J W Henry
1Henry Ford Heart and Vascular Institute, Detroit, Michigan 48202.
Abstract:
This investigation examines the hypothesis that hypertrophy attenuates wall stress during exercise, when left ventricular wall tension is highest and most likely to contribute to hypertrophy. Upright bicycle exercise was performed by 17 endurance-trained male athletes and 15 sedentary men. M-mode echocardiograms were obtained during submaximal exercise at predetermined heart rates. At all levels of exercise, at a matched heart rate, wall tension was higher in athletes than in sedentary subjects. In both groups, wall tension increased with exercise, then plateaued. Wall stress did not differ significantly in athletes and sedentary subjects at rest and at heart rates of 110 and 150 beats/min, although a difference was observed at a heart rate of 130 beats/min. Wall stress decreased in both athletes and sedentary subjects with exercise. In conclusion, left ventricular hypertrophy caused wall stress in athletes to be maintained at values similar to sedentary subjects during exercise as well as at rest.