Asynchronous Movement of Mitral Annulus: An Additional Mechanism of Ischaemic Mitral Regurgitation

Abstract

In-coordinate mitral annulus movement might participate in the pathogenesis of functional mitral regurgitation. We evaluated a relationship between indices of mitral annulus systolic asynchrony and mitral regurgitation in patients after myocardial infarction in order to determine independent determinants of effective regurgitant orifice (ERO) area in a multivariate regression model. Tissue Doppler echocardiographic studies and quantitative analysis of mitral regurgitation were performed in 40 patients (33 men, 7 women, mean age 60.1 +/- 9.2 years) with a history of Q-wave myocardial infarction, with and without significant functional mitral regurgitation.A multivariate regression model showed that mitral annulus movement asynchrony index-difference between the longest and the shortest time from the R wave in the electrocardiogram to the cessation of systolic movement of the four aspects of mitral annulus, is an independent from ejection fraction, sphericity index, tenting, annulus diameter and infarct location, determinant of mitral regurgitation ERO area (r(2) change 0.72, p <or= 0.01). The only other independent predictor of ERO area was mitral annulus diameter (r(2) change 0.79, p <or= 0.01). Other variables were predictors of ERO only in univariate analyses: ejection fraction (r(2) change 0.59, p <or= 0.01), tenting area (r(2) change 0.76, p <or=0.01 ) and sphericity index (r(2) change 0.75, p <or=0.01). In conclusion, mitral annulus asynchrony is an additional mechanism contributing to the development of functional mitral regurgitation. This suggests, that cardiac resynchronization might be considered, either as a first line intervention in patients with mitral regurgitation not considered for mitral surgery or as a supplementary measure, when results of surgery are suboptimal.