Importance of left ventricular longitudinal function and functional reserve in patients with degenerative mitral regurgitation: assessment by two-dimensional speckle tracking.

BACKGROUND: The aim of this study was to determine whether two-dimensional speckle tracking of longitudinal myocardial deformation can detect limited contractile reserve during exercise in patients with asymptomatic degenerative mitral regurgitation (MR).

METHODS: Seventy-one patients with degenerative MR and normal left ventricular (LV) ejection fractions underwent quantitative exercise echocardiography.

RESULTS: Compared with 23 normal subjects matched for age and sex, LV volumes were greater in patients with MR. At rest, global longitudinal strain (GLS) was lower in patients, indicating subclinical LV dysfunction. During exercise, the extent and the magnitude of changes in GLS were larger in controls than in patients with MR. On multivariate regression analysis, left atrial volume at rest and changes in GLS at peak exercise were independently associated with changes in LV ejection fraction.

CONCLUSION: In asymptomatic patients with degenerative MR, subnormal LV function can be reliably identified by two-dimensional strain imaging. Limited exercise LV longitudinal contractile recruitment during exercise predicts postoperative LV dysfunction.