Relation of Mitral Annular Dilation with Dynamic Mitral Regurgitation in Patients with Rheumatic Mitral Regurgitation

Introduction: Dynamic mitral regurgitation (MR) is frequently investigated in patients with left ventricular systolic dysfunction (LVSD). Data about the dynamic MR in patients with organic valve disease are limited. The aim of this study was to evaluate the alteration of MR by exercise in patients with rheumatic valve disease (RVD). Methods: Asymptomatic patients with rheumatic MR and normal left ventricular function had been included in our study. Transthoracic echocardiography and Doppler measurements were performed at rest and just after submaximal exercise test performed with treadmill. Severity of MR was evaluated quantitatively by measuring effective regurgitant orifice area (EROA) with flow convergence method. Results: A total of 34 patients with rheumatic MR had been included. Severity of MR increased in 10 patients with exercise (Group 1) and decreased in 24 of them (Group 2). When the variables of two groups were compared; diastolic blood pressure after exercise, EROA, left atrial volume, left ventricular diastolic volume and mitral annular area values were significantly higher in Group 1 patients. A linear regression model was constructed by considering change of EROA by exercise the dependent, and the variables showing significant differences as the independents. Mitral annular area was found to be independently associated with EROA increase with exercise (R2= 0.499; P < 0.001). Conclusion: Mitral annular dilation is independently associated with increase of MR with submaximal exercise in asymptomatic patients with MR due to RVD with normal left ventricular function.