Evaluation of Subclinical Left Ventricular Dysfunction in Diabetic Patients: Longitudinal Strain Velocities and Left Ventricular Dyssynchrony by Two‐Dimensional Speckle Tracking Echocardiography Study

Abstract

We evaluated left ventricular (LV) subclinical systolic dysfunction in diabetes mellitus patients using two-dimensional speckle tracking echocardiography (STE) for early detection of changes in LV longitudinal strain (ST) or synchronized contraction. To determine ST and LV dyssynchrony, 37 normal coronary and normotensive diabetes mellitus patients with LV ejection fraction >50% were enrolled and compared to 39 nondiabetic normal coronary and LV function subjects. The cases underwent standard conventional transthoracic echocardiography and tissue Doppler imaging (TDI) and STE. End-systolic ST and time-to-peak systolic strain (Ts) were measured in 18 LV segments. Conventional parameters were similar between diabetic and nondiabetic subjects. In diabetic patients, significant reduction in global and segmental ST adjusted for age and body mass index, independently correlated with early diastolic velocity at the septal mitral valve annulus by TDI (P = 0.001), ratio of transmitral early and late diastolic velocities (P < 0.001), relative wall thickness (P = 0.014), glycosylated hemoglobin (P < 0.001), and fasting blood sugar (P < 0.001). These correlations were not found in the nondiabetic patients. After adjustment, presence of diabetes mellitus remained an independent correlate of reduced LV global longitudinal ST (R = 0.688, P = 0.003). Delay of Ts between the anteroseptal and posterior walls and all the LV segments was markedly higher in the diabetic group regardless of diastolic dysfunction. In diabetic patients with normal coronary and ejection fraction, segmental and global end-systolic longitudinal ST decreased and differences between Ts among LV segments increased irrespective of diastolic dysfunction at early stage. These results suggest that there might be early detectable changes in systolic function in the natural course of diabetes mellitus by STE study.