Abnormal septal motion after aortic valve replacement for chronic aortic regurgitation: no evidence for myocardial ischaemia by exercise radionuclide angiography.

To evaluate interventricular septal motion and left ventricular function after aortic valve replacement for chronic aortic regurgitation, we studied 12 patients at rest and during exercise by radionuclide angiography after a mean of 19 (range 12-36) months after operation (group I). Twenty patients with chronic aortic regurgitation without aortic valve replacement served as controls (group II). None of the patients had coronary artery disease as documented by arteriography. Abnormal interventricular septal motion at rest was seen in 11 patients of group I, of whom 8 showed hypokinesis and 3 akinesis. During exercise, the interventricular septal wall motion improved in 4 patients, worsened in 3 patients and did not change in 5 patients. All patients of group II had normal interventricular septal motion at rest. During exercise, 5 patients showed septal wall hypokinesia together with apical and posterolateral wall motion abnormalities. The left ventricular ejection fraction at rest was 62% +/- 20% in group I and 66% +/- 8% in group II (not significant). During exercise, the left ventricular ejection fraction was 59% +/- 24% in group I and 68% +/- 13% in group II (not significant). We conclude that abnormal interventricular septal motion at rest is commonly found in patients with aortic valve replacement for chronic aortic regurgitation. During exercise, septal wall motion in the patients with aortic valve replacement shows a variable response from complete normalization to akinesia. These findings are mostly associated with a normal global left ventricular function both at rest and during exercise, which precludes myocardial ischaemia as a primary cause for abnormal septal wall motion after aortic valve replacement.