Echocardiography to measure fitness of elite runners.

We evaluated the echocardiograms of 134 male and 54 female elite runners who competed over different distances to observe cardiac enlargement and differences among athletes engaged in different types of training, and to relate the echographic dimension with running performance. In male runners, left ventricular (LV) internal diameter at end diastole (LVIDd), LV mass, and left atrial diameter were increased by the length of distance ( P < .001) whereas right ventricular diameter was increased only in marathon runners. In female runners, this association was found when LVIDd, LV mass, and left atrial diameter were adjusted for body surface area ( P < .001). Wall thickness was not related to distance running. Abnormal LV dilation was associated with a low LV ejection fraction for the higher values of LVIDd, but not for the higher indexed LVIDd values. In male runners, LVIDd was associated with 100 m ( r = -0.67, P < .01), 10,000 m ( r = -0.70, P < .001), and marathon ( r = -0.54, P < .001) and in female runners with a 400-m ( r = -0.84, P < .001) race time. These results show that sprint- and endurance-trained runners had an eccentric hypertrophy and that it is necessary to establish a new upper limit of abnormal cavity dilatation as indexed LVIDd. The normal systolic function and the relationship between LVIDd and performance indicate that LV enlargement in elite runners is a physiologic adaptation and that echocardiographic assessment can be used to determine the fitness of runners.