Effects of isometric handgrip and dynamic exercise on left-ventricular function.

Radionuclide angiocardiography was used to assess cardiac function during isometric handgrip and bicycle exercise in ten normal volunteers and in 20 patients with documented coronary artery disease. Handgrip stress evoked a small increase in cardiac output that resulted from a concomitant increase in heart rate and no change in left-ventricular function. The most reliable criterion for diagnosis of coronary artery disease by handgrip was development of a new well-motion abnormality. However, abnormal wall motion was observed in only 45% of patients with coronary artery disease and in one of the ten normal subjects. In normal subjects, left ventricular function during bicycle exercise was characterized by an increase in left-ventricular ejection fraction with little change in cardiac volumes. The failure to increase left-ventricular ejection fraction by at least 0.05 identified 19 to 20 patients with coronary artery disease with no false positives. Therefore, bicycle exercise evokes a more dramatic cardiovascular response than handgrip stress and is the preferable stress modality for inducing abnormalities of left-ventricular function for detection of coronary artery disease.