Left ventricular functional assessment by radionuclide ventriculography during isometric handgrip and bicycle exercise in patients with aortic insufficiency.

Twelve patients with chronic aortic insufficiency underwent radionuclide ventriculography performed in conjunction with dynamic bicycle and isometric handgrip exercise. Changes in left ventricular ejection fraction (LVEF) during exercise were measured. In all patients, the degree of regurgitation was determined by catheterization, and in eight patients, left ventricular end-diastolic pressure (LVEDP) was measured. The change in LVEF during either form of exercise was inversely related to the LVEDP. This correlation was somewhat better and more linear for bicycle exercise (R=0.84, p <.005) than for handgrip (R = 0.71, p<.025). By either exercise technique, a decrease in LVEF by >4 points occurred only in patients with 3 to 4 + regurgitation. We conclude that although radionuclide ventriculography with either bicycle or handgrip exercise is useful in determining the effect of aortic insufficiency on left ventricular functional reserve, bicycle exercise correlates better with other criteria of ventricular dysfunction.