Alteration of mitral regurgitation severity by exercise in asymptomatic patients with rheumatic mitral regurgitation and normal left ventricular function

ABSTRACTALTERATION OF MITRAL REGURGITATION SEVERITY BY EXERCISEIN ASYMPTOMATIC PATIENTS WITH RHEUMATIC MITRALREGURGITATION AND NORMAL LEFT VENTRICULAR FUNCTIONDr. Çağlar Emre ÇAĞLIYAN, Residency Thesis, Department of CardiologySupervisor: Associate Prof. Dr. Vedat DAVUTOĞLUFebruary 2007, 77 pagesWe aimed to investigate the alteration of mitral regurgitation severity byexercise in asymptomatic patients with rheumatic mitral regurgitation andnormal left ventricular function. Mitral regurgitation severity was determinedprimarily by flow convergence method. Treadmill stress echocardiography hadbeen performed to 34 patients who had admitted to our study. Subjects?response to exercise was evaluated by Paired Samples T Test. Ejection fractionand cardiac output values increased significantly with exercise in all patients(p<0.001). Since systolic period shortens with tachycardia, we evaluated thepatients due to alterations in their regurgitant volume per minute to avoid theeffects of exercise on regurgitant volumeMitral regurgitation volume per minute decreased in 19 patients (Group 1)while the same parameter increased in the rest 15 patients (Group 2). Chi-square and Mann-Whitney-U tests were used to compare both groups witheach other. Eccentric jet proportion was significantly higher in Group 2(p=0.025). Regurgitant volume, mitral annular area at rest and maximalgradient between left ventricle and left atrium post-exercise values weresignificantly higher in Group 2 (in sequence: p=0.009, p=0.036 ve p=0.005).Mitral annuler area value was the only independent factor correlating withalterations in regurgitant volume per minute (R²=0,43, p<0,001) and effectiveregurgitant orifice area (R²=0.50, p<0.001).In conclusion, mitral annular dilatation is the most important predictor ofaugmentation in mitral regurgitation severity by exercise in asymptomaticpatients with rheumatic mitral regurgitation and normal left ventricular function.Regurgitant volume quantity at rest and afterload alterations by exercise mayalso contribute to augmentation of regurgitant volume per minute.Key words: Flow convergence, Treadmill stress echocardiography, Eccentricjet, Regurgitant volume, Effective regurgitant orifice area