Exercise hemodynamics in aortic regurgitation

The hemodynamic response to supine exertion was studied by left heart catheterization in 23 Functional Class II and III subjects with isolated aortic regurgitation. The resting cardiac index was normal in most patients but rose insufficiently with exercise in 11. The 12 subjects with a normal cardiac index during exercise usually had elevated left ventricular end-diastolic pressures, while those with a low cardiac index usually had normal pressures. The difference was statistically significant. The explanation for this unusual finding is not clear from the data but might be forthcoming if similar studies employing quantitative angiocardiography were performed.