Value of isometric exercise testing in the optimal timing of aortic valve replacement in aortic regurgitation

To evaluate the possible irreversibility of isometric exercise-induced left ventricular dysfunction in aortic regurgitation, we performed handgrip exercise tests during cardiac catheterization on 17 patients with chronic aortic regurgitation (AR-group), both preoperatively and one year after successful aortic valve replacement. Nine normal subjects served as a control group. Preoperatively, the ejection fraction decreased from 59 +/- 7% to 53 +/- 8% (P less than 0.001) in the AR-group while it remained unchanged in the control group during exercise. A positive correlation existed between the changes in the ejection fraction during pre- and postoperative exercise tests (r = 0.85, P less than 0.001), which revealed that in patients with severely depressed ejection fraction during the preoperative exercise test, the ventricular response to exercise was not totally corrected after surgery. The regression of left ventricular mass was also smaller in the patients with most depressed ventricular response to exercise preoperatively. As the isometric exercise-induced left ventricular dysfunction appears to be partly irreversible, we conclude that the valve replacement should perhaps be performed before stress-induced ventricular dysfunction has occurred. Non-invasive monitoring of ventricular response to exercise might be helpful in optimizing the timing of valve replacement in aortic regurgitation.