[Exercise echocardiography to evaluate left ventricular function in mitral and aortic regurgitation].

To assess differences in left ventricular (LV) performance between mitral regurgitation (MR) and aortic regurgitation (AR), exercise echocardiography was performed for 12 patients with MR and 18 patients with AR, and the results were compared with those of 11 normal subjects. These patients with LV volume overloads were all in the NYHA class I or II. There were no differences in age or sex distributions between the two groups. Symptom-limited submaximal exercise was performed on an ergometer in the supine position. The results obtained were as follows: LV dimensions at end-diastole (EDD) and end-systole (ESD) were greater in the diseased groups than in the normal group. Resting EDD and ESD showed no differences between the MR and the AR groups. There were no differences in exercise-induced increases in heart rates or elevations of systolic blood pressures among the three groups. During exercise, EDD increased and ESD decreased in the normal group, and similar results were obtained for the MR group. However, in the AR group, EDD and ESD remained unchanged. Ten of the 18 patients with AR had decreased ESD, and eight had unchanged or increased ESD during exercise. Resting shortening fractions were equally distributed among the three groups. During exercise, the shortening fractions were significantly increased in the normal and the MR groups. In the AR group, shortening fractions remained at resting values, with variable responses in individual cases. Systolic wall thickening of the interventricular septum and the LV posterior wall showed similar responses of shortening fractions. The relation between the peak systolic wall stress index (PSSI) and ESD, or PSSI and the shortening fraction revealed that exercise induced an afterload mismatch of LV performance in some patients with AR. Thus, though resting LV performances did not differ from each other, an afterload mismatch is more easily induced with exercise in patients with AR than in patients with MR. This may be one of the cause of the different clinical courses in these two groups with LV volume overloads.