Static Versus Dynamic Exercise: Effects on Doppler Echocardiographic Indices of Left Ventricular Performance

Summary : In order to compare the effects of static exercise with those of dynamic exercise on the Doppler echocardiographic measurements of ascending aortic blood flow velocity and acceleration, Doppler echocardiography was performed with sustained handgrip exercise and with supine bicycle exercise in 12 normal subjects, 12 patients with coronary artery disease, and 7 patients with heart failure. In normal subjects: peak velocity decreased by 16±11% with handgrip from the resting value and increased by 49±19% with bicycle exercise (p>0.01); mean acceleration decreased by 6±30% with handgrip and increased by 162±83% with bicycle exercise (p>0.01). In patients with coronary artery disease: peak velocity declined by 9±14% with handgrip and increased by 19± 18% with bicycle exercise (p>0.01); mean acceleration increased by 13±27% with handgrip and by 41 ±33% with bicycle exercise (NS). In patients with congestive heart failure: peak velocity decreased by 19±13% with handgrip and increased by 5±17% with bicycle exercise (p>0.01); mean acceleration decreased by 12±23% with handgrip and by 4±37% with bicycle exercise. A marked increase in afterload stress induced by static exercise presumably offsets the moderately increased contractility and accounts for the decline of peak velocity and mean acceleration with static exercise both in normals and cardiac patients. In contrast, marked increase in contractile state along with little change in afterload with dynamic exercise results in markedly increased peak velocity and mean acceleration in normal subjects. In cardiac patients, however, the increase in peak velocity and mean acceleration with dynamic exercise are blunted. The changes in peak velocity and mean acceleration with handgrip are similar in normal subjects and cardiac patients. On the other hand, changes in these variables with dynamic exercise are markedly different in normal subjects and cardiac patients. Doppler echocardiographically measured peak velocity and mean acceleration respond differently to static and dynamic exercise. Measurement of these variables with dynamic exercise is more useful in evaluating left ventricular systolic function than static exercise.