Assessment of regional left ventricular functions by strain and strain rate echocardiography in type II diabetes mellitus patients without microvascular complications

Abstract

We evaluated regional left ventricular myocardial functions by strain (S) and strain rate (Sr) echocardiography in patients with type II diabetes mellitus (DM) without microvascular complications. The study included 40 DM patients (20 women, 20 men; mean age 52.4 ± 7.9 years) without microvascular complications, and 40 healthy controls (20 women, 20 men; mean age 52.8 ± 10.1 years). Left ventricular functions were evaluated by conventional Doppler, tissue Doppler, and S-Sr echocardiography. Longitudinal peak systolic S and Sr were measured from the basal, mid and apical segments of the left ventricle walls. Patients with DM duration of >3 years (n=24) and receiving medical therapy for DM (n=30) were also evaluated. Conventional Doppler findings were similar in the patient and control groups. Among tissue Doppler variables, only early diastolic mitral annular velocity (Em) was significantly decreased (10 ± 2.9 vs. 11.4 ± 3.2 cm/sec, p<0.05), and accordingly, mitral inflow E/Em ratio was significantly increased (7.3 ± 2.5 vs. 6.3 ± 2, p<0.05) in patients with DM. The two groups were similar with respect to systolic S and Sr values, except for apical-lateral S, mid-anterior S, basal-anteroseptal S, apical-anterior Sr, and mid-anteroseptal Sr (p<0.05, for all). Patients with DM duration of >3 years and receiving medical therapy showed similar changes as the overall patient group. The frequency of left ventricular diastolic dysfunction was higher in patients with DM. Irregular distribution of systolic S and Sr indices in the left ventricular segments may indicate that DM leads to heterogeneous myocardial involvement also in the early period.