Myocardial Systolic Velocities and Deformation Assessed by Speckle Tracking for Early Detection of Left Ventricular Dysfunction in Asymptomatic Patients with Severe Primary Mitral Regurgitation

Abstract

In asymptomatic patients with severe primary mitral regurgitation (PMR), early detection of left ventricular (LV) dysfunction indicates the optimal timing of mitral valve surgery; however, normal ejection fraction (EF) and end-systolic diameter (ESD) can mask significant LV impairment. We studied 28 asymptomatic patients (59 ± 13 years, 18 male) with severe PMR, EF > 60%, and ESD < 45 mm, and 10 age-matched healthy subjects. All underwent echocardiography with tissue velocity imaging to assess LV geometry, EF, and longitudinal systolic function; and two-dimensional speckle tracking to assess longitudinal strain (LS) and longitudinal strain rate (LSR), and radial strain (RS) and radial strain rate (RSR). Patients were reevaluated 14 days after successful mitral valve repair and divided in: IA, with a postoperative EF reduction >10% (13 patients) and IB, with an EF reduction <10% (15 patients). Patients with PMR had longitudinal dysfunction and decreased radial systolic deformation, by comparison with controls, although EF and ESD were similar. Subgroup IA had significantly lower S(TVI) , LS, and RS than IB (7.3 ± 0.9 vs 10.8 ± 1.5 m/s; -16.0 ± 4.2% vs -21.7 ± 2.1%; and 37.4 ± 2.5% vs 41.6 ± 2.4%; all p < 0.001) although preoperative LV mass index, LV diameters, and EF were similar. Multiple stepwise regression analysis showed that S(TVI) and the combination of S(TVI) and LS represent the main independent predictors for a postoperative EF reduction >10% (r(2) = 0.52, p < 0.001; and r(2) = 0.70, p < 0.001, respectively). Myocardial systolic velocities as well as radial and longitudinal LV deformation assessed by speckle tracking can detect subclinical LV dysfunction and predict impaired postoperative LV function in asymptomatic patients with severe PMR.