Post-exercise echocardiography in pre-pubertal boys.

Echocardiography offers many advantages for non-invasively assessing cardiac function during exercise, but the use of this technique is hampered by interference created by respirations and body motion. The persistence of alterations in ventricular dimensions in the immediate post-recovery period, however, provides an artifact-free opportunity for evaluating recovery from the inotropic response of exercise stress. To determine the feasibility of this technique for children and to examine typical values in the pre-pubertal population, 20 boys had two-dimensional directed left ventricular M-mode echocardiograms performed before and after maximal treadmill exercise. Acceptable measurements were possible by 2 min of recovery in all subjects. Mean left ventricular shortening fraction at this time was increased 10% from resting values as a result of decreased end-systolic dimension. This study demonstrated the feasibility of post-exercise echocardiography in evaluating recovery left ventricular dimensions, but further examination of specificity, validity, variability, and reproducibility of this technique will be important in assessing its clinical usefulness.