[Left ventricular contractile reserve in asymptomatic patients with primary mitral regurgitation].

This study aimed to quantify left ventricular contractile reserve (LVCR) and to evaluate its usefulness for risk stratification in asymptomatic patients with primary mitral regurgitation (MR). Resting and exercise echocardiography including two-dimensional speckle tracking was performed in 115 consecutive asymptomatic patients with moderate to severe primary MR. LCVR was defined as an exercise-induced increase in LV ejection fraction ≥ 4% or in LV global longitudinal strain ≥ 2%. LVCR was absent in approximately one half of the population. This absence was a strong independent predictor of cardiac events when assessed by exercise-induced changes in LV longitudinal function, but not when measured by exercise-induced changes in LV ejection fraction.