Evaluation of ECG Abnormalities in Patients with Asymptomatic Type 2 Diabetes Mellitus

Diabetes Mellitus (DM) is the most common chronic disease. DM is considered a Cardiovascular Disease (CVD) risk equivalent. Its macrovascular complications are associated with two-fold increased risk of premature atherosclerotic CVD. Most of the diabetics with cardiovascular involvement are asymptomatic. Electro Cardio Graph (ECG) abnormalities are found to be predictors of silent ischaemia in asymptomatic persons. An abnormal ECG response is associated with statistically significant high risk for cardiac mortality and morbidity.

The aim of the study was to evaluate ECG changes in asymptomatic Type 2 DM patients.

A cross-sectional comparative study was conducted in a tertiary care hospital in North India. One hundred diabetics presenting to Medicine OPD/IPD were included in the study who had no symptoms of heart disease and no diabetic complications. Fifty person with age and sex matched controls were included in the study. Relevant history and physical examination findings were recorded in a protocol. The variables studied were: gender, age, smoking, physical activity, and waist circumference, Body Mass Index (BMI) and blood pressure. Resting ECG was recorded.

Mean age of asymptomatic diabetic patients was 50.3±11.90 years (age range 25-75 years). In this study, none of the control group had ECG abnormality whereas, 26% asymptomatic diabetics had ECG abnormalities. Most of the asymptomatic cases with ECG changes had 5-10 year of duration of diabetes mellitus; 70% patients with ECG changes had poor glycaemic control, increased triglyceride and decreased High Density Lipoprotein (HDL) levels. Most common abnormality observed was ST-T changes, followed by Left Atrial Enlargement (LAE), Left Ventricular Hypertrophy (LVH), Left Bundle Branch Block (LBBB) and Right Bundle Branch Block (RBBB).

ECG changes are present in quarter of asymptomatic Type 2 DM patients. However, nonspecific ST-T changes, LVH and LAE are common.