Chronic Hyperglycemia and Inhomogenous Ventricular Repolarisation - an Electrophysiological Approach

The QT interval expresses the myocardial depolarization and repolarisation time. QTd is regarded as an index of myocardial electrical activity. Present study was done to investigate the differences in QTd between non-diabetics, well controlled diabetes patients and poorly controlled diabetics. The study group comprised of 60 type 2 diabetes patients within the age group of 40–60 years coming to diabetic clinic and those hospitalized in medicine wards, They were further classified in to two sub-groups(n = 30 in each group), Type2 diabetes patients with good glycemic control (HbA1c < 7). And Type2 Diabetes patients with poor glycemic control (HbA1c > 7). Glycosylated hemoglobin level was detected by calorimetric method (spectronic -2). The control group consisted of 30 age matched healthy subjects (volunteers). After thorough examination of the subjects as per the proforma, 12 lead ECG was taken with (Montara instrument ELI 250), QT interval was measured on the 12 lead resting ECG. QTd was calculated manually. The value of QT dispersion was significantly high (p < 0.01) in Type2 Diabetes mellitus patients with poor glycemic control compared to well controlled diabetics and healthy subjects. Chronic hyperglycemia is associated with high QT dispersion which suggests that such patients have a greater inhomogeneity of repolarization and therefore they are more prone for adverse cardiovascular events.