Rapid resolution of hyperkinesis after exercise. Two-dimensional echocardiographic studies in normal subjects.

Abnormal wall motion detected with exercise echocardiography identifies ischemic myocardium, while normal myocardium exhibits hyperkinetic motion. The normal, hyperkinetic response to exercise is transient and is predictive of an excellent prognosis. However, there are few data on the duration of the hyperkinesis after peak exercise. Our purpose was to determine the time course of wall thickening after exercise in eight normal subjects with two-dimensional echocardiography. Percentage of wall thickening increased from 53 +/- 24 percent at baseline to 82 +/- 24 percent at 0 to 2 min postexercise (p < 0.001 vs baseline) and then decreased to 64 +/- 27 percent at 2 to 4 min, and 54 +/- 20 percent at 5 to 7 min (both NS vs baseline). We conclude that (1) systolic wall thickening is maximal within the initial 2 min following peak exercise, and (2) accurate identification of hyperkinetic, normal myocardium with exercise echocardiography requires immediate postexercise imaging.