The Effects of 6 Minutes Walking Exercise on the Secondary Mitral Regurgitation

Özet

Background: Mitral Regurgitation (MR) is usually insidious due to progressive remodeling of atrial and left ventricle (LV). In secondary MR, the mitral valve apparatus are structurally normal but dysfunctional because of ischemic or non-ischemic cardiomyopathy. The aim of this study was to identify echocardiographic MR variables associated with 6 Minute Walk (6MW) exercise in patients with non-ischemic cardiomyopathy. Methods: This prospective study involved 81 consecutive patients with clinically stable non-ischemic LV dysfunction (ejection fraction lower than 40%) and at least mild MR who were able to perform symptom limited 6MW exercise. All the patients underwent standard Doppler echocardiography examination and each patient had a recent normal coronary angiography. All patients were evaluated for their functional capacities, stratified by New York Heart Association classification and underwent echocardiography evaluation before 6MW aerobic exercise and after 6 months. The severity of regurgitation established by a comprehensive evaluation of color and conventional Doppler criteria. Results: Proximal isovelocity surface area (PISA) decreased significantly from 42 (17-64) to 29 (12-47) mm2 (p<0.001). Regurgitant orifice area calculated by the PISA method decreased significantly from 27 (16-41) to 20 (10-34) mm2 (p<0.001). The regurgitant volume calculated by the quantitative Doppler method, and vena contracta width decreased significantly from 0.43 (0.20- 0.60) to 0.40 (0.20-0.50) cm (p<0.001). There was no significance difference at baseline and after six months for LV end diastolic diameter and diastolic function parameters. Conclusion: We conclude that a simple, easily reproducible 6MW exercise might supplement the assessment of the grade of MR in secondary MR patients.