Left Ventricular Structure and Function in Exercise-Induced Eccentric Hypertrophy

Abstract

The influence of exercise training on left ventricular (LV) geometry and function was studied by 2Dguided M-mode computerized echocardiography in 14 athletes who underwent a predominantly endurance training program. Twenty age-matched untrained subjects served as controls. After a rigorous 28-week training, LV mass was increased (159 ± 27 g/m^2, p < 0.001 vs. 95 ± 20 of controls), with normal values of relative wall thickness (Th/R) and end-systolic meridional wall stress (ESS), suggesting an adequate LV eccentric hypertrophy. Fractional shortening values and the relation between LV ESS and fractional shortening excluded alterations in systolic pump performance. Also, no impairment in LV relaxation and filling indices was observed. When restudied 8 weeks after interruption of exercise, when the reconditioning had just begun, LV mass was still increased, though to a smaller degree (117 ±21 g/m^2, p < 0.001 vs. control values). Eccentric LV hypertrophy was adequate in 9 athletes, whereas 5 athletes showed low Th/R and high LV ESS values. This inadequate LV eccentric hypertrophy was probably due to an abrupt increase in workload. However, systolic and diastolic LV function analysis showed no abnormalities in any subject. We conclude that LV myocardial properties are not affected in exercise-induced LV eccentric hypertrophy. Our results provide new information on the regression of LV hypertrophy after cessation of training.