FACTORS AFFECTING THE POSTOPERATIVE EXERCISE CAPACITY OF PATIENTS WITH MITRAL-STENOSIS AND AORTIC REGURGITATION

Factors affecting the exercise capacity of patients with mitral stenos is (MS) and aortic regurgitation (AR) are incompletely understood. Acc ordingly, exercise capacity was assessed in 13 patients with MS and in 13 with AR by means of cardiopulmonary exercise testing before as wel l as 3, 6 and 12 months after valve replacement. Left- and right-ventr icular function were evaluated echocardiographically. Both in MS and i n AR exercise capacity expressed by maximal oxygen consumption (V-O2ma x) increased significantly after valve replacement and was directly re lated to right ventricular (RV) function assessed by the ratio of RV a cceleration time to RV ejection time (r = 0.87, p < 0.001 and r = 0.74 , p < 0.001, respectively) and inversely related to left atrial diamet er (r = -0.72, p < 0.001 and r = -0.76, p < 0.001, respectively). No r elation between V-O2max and resting left-ventricular function was foun d. Thus, the postoperative improvement in the exercise capacity both i n mitral stenosis and in aortic regurgitation is associated with an im provement in right-ventricular function and a decrease in left-atrial size.