[Long-term effect of medical treatment in patients with chronic aortic regurgitation].

We often experience patients with chronic severe aortic regurgitation (AR) whose cardiac function significantly improves by medications, especially by vasodilator therapy. To find the factors determining the response to pharmacologic treatment, we studied 20 patients with chronic AR with dilated left ventricle (end-diastolic dimension > or = 55 mm) using echocardiography; 9 patients with significant improvement (delta Ds < or = -3 mm: improved group) and 11 without improvement (unchanged group). In the initial evaluation, systolic blood pressure and left ventricular relative wall thickness (Thd/Dd) were greater and left ventricular end-diastolic dimension was smaller in the improved group than in the unchanged group. During the follow-up period, systolic blood pressure and end-systolic wall stress decreased significantly and absolute and relative wall thickness increased significantly in the improved group, however, they remained nearly the same in the unchanged group. Significant negative correlation was observed between Thd/Dd and delta Ds. In conclusion, cardiac function in some patients with chronic AR can be improved by pharmacologic treatment, and in such cases, the Thd/Dd ratio could be a parameter of the response to pharmacologic treatment.