[Left ventricular longitudinal rotation changes in patients with dilated cardiomyopathy detected by two-dimensional speckle tracking imaging].

ABSTRACT

OBJECTIVE: To assess the left ventricular longitudinal rotation (LR) in patients with dilated cardiomyopathy (DCM). METHODS: Conventional echocardiography (GE-Vivid7) was performed in 35 healthy subjects and 42 DCM patients. Left atrial diameter was measured by M-mode echocardiography, left ventricular end-systolic, end-diastolic volume and left ventricular ejection fraction (LVEF) were calculated by bi-plane simpson's method. The peak velocity during early diastole (Ve) and late diastole (Va) of anterior mitral valve were measured by pulse-waved doppler, and the ratio Ve/Va was calculated. The peak radial systolic strain, strain rate in systolic, early and late diastolic periods were measured. Segmental LR and global LR were assessed using two-dimensional speckle tracking imaging (2D-STI). RESULTS: The peak radial systolic strain, strain rate in systolic, early and late diastolic periods in DCM group were significantly lower than in healthy subjects, the rotation degrees of the middle and base lateral, the apex and the base septum walls were significantly lower than those of the healthy subjects. A prominent counterclockwise LR (0.76° ± 2.63°) was shown in healthy subjects while prominent clockwise LR (-1.58° ± 3.42°) was present in DCM patients. The time delay between the left ventricular lateral wall and the base septum wall in DCM patients significantly correlated with the peak LR of the left ventricular (r = 0.409, P < 0.01; r = 0.396, P < 0.01). CONCLUSIONS: 2D-STI can be used to assess the LR in DCM patients and a clockwise LR is present in DCM patients which might be caused by the time delay between the left ventricular lateral wall and the base-septum wall.