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

Objectives: 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.
Study design: 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.
Results: 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.
Conclusion: 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.

Keywords: Diabetes mellitus, type 2/complications, echocardiography; myocardial contraction; stress, mechanical; ventricular function