Abstract 2249: Effects of Mechanical Asynchrony on Mitral Regurgitation After Acute Myocardial Infarction: The VALIANT Echo Study
Mitral regurgitation (MR), a common complication of myocardial infarction (MI), is associated with adverse outcomes. However, the association between mechanical asynchrony and MR following MI is not well understood. We examined the relationship between left ventricular (LV) asynchrony and MR in 329 patients with LV dysfunction, heart failure, or both following MI from the VALsartan In Acute myocardial iNfarcTion (VALIANT) echo study. MR was categorized by mapping jet area in the left atrium. Two-D speckle tracking utilizing velocity vector imaging (Siemens Inc) was applied to apical 4- and 2-chamber views, and the standard deviation of time to regional peak velocity among 12 LV segments was used as a measure of global asynchrony. In addition, we assessed regional asynchrony by assessing each of 4 segments within the apical, mid, and basal regions. Increased mechanical asynchrony was associated with a greater degree of MR, even after adjustment for LV ejection fraction and LV end diastolic volume (P=0.036) (Table⇓). Both mitral valve tenting area and coaptation depth were increased with greater degrees of asynchrony, particularly within the basal region of the left ventricle (P<0.02). LV asynchrony, particularly within the basal portion of the left ventricle, after MI is associated with increased MR independently of ventricular size or function, suggesting that an altered contraction pattern may be important contributor to MR following MI.