Assessment of left ventricular systolic function by tissue Doppler imaging in controlled versus uncontrolled type 2 diabetic patients

Aim

To detect and quantify early subtle left ventricular (LV) systolic dysfunction using Tissue Doppler Imaging in type 2 diabetic patients with apparently normal LV ejection fraction.

Methods

Ninety age and sex matched subjects were enrolled in the study, sixty of them were suffering from type 2 diabetes mellitus (DM) whom were divided according to HbAlc into 2 groups, 30 uncontrolled diabetic patients with HbAlc > 8% and 30 controlled diabetic patients with HbAlc < 8% and a third group of 30 normal subjects served as controls. We excluded patients with inadequate Doppler signal, all structural heart diseases, systemic disorders with cardiac involvement and patients with false positive HbAlc. Assessment of diastolic function was done by Pulsed Doppler through mitral flow and by propagation flow velocity. Assessment of left ventricular systolic function was done by conventional echocardiography by 2D Simpson method and by Tissue Doppler Imaging (TDI) through detection of mitral annular peak systolic velocities.

Results

Left ventricular diastolic function was compared between the studied groups and showed that the mean peak early mitral inflow velocity E wave and the color M-mode flow propagation velocity of early diastolic flow (Vp) were significantly lower, and the mean peak late mitral inflow velocity A wave was significantly higher in uncontrolled diabetics versus controlled diabetic patients and control group with highly significant statistical difference (p < 0.001). Assessment of global systolic function by conventional Simpson’s modified biplane method didn’t show significant difference between uncontrolled diabetic patients, controlled diabetic patients and normal individuals. However, evaluation of systolic function by Tissue Doppler Imaging showed that the mean peak longitudinal systolic velocity was significantly decreased in uncontrolled diabetic patients when compared to controlled diabetic patients and normal individuals, with highly significant statistical difference (p < 0.001). A cut-off value for systolic dysfunction detected by TDI in uncontrolled diabetic patients was calculated. The peak systolic velocities < 7 cm/s for medial mitral annulus and < 8.2 cm/s for lateral mitral annulus indicated systolic dysfunction in diabetic patients with sensitivity and specificity of 96% and 67% respectively for medial mitral annulus while 98% and 71% respectively for lateral annulus.

Conclusion

TDI is a simple and effective method for detection of subtle LV systolic dysfunction in type 2 uncontrolled diabetic patients.