Introduction: There are various physiological factors that affect ECG waveforms which include sex, age, ethnicity, height, weight, body mass index, and pregnancy and produce inter individual variability in ECGs. Hypothesis: The present study was done to find out the electrocardiographic changes in relation to body mass index. Approach: The study was conducted in the Physiology department, VIMS, Bellary. 30 normal, 30 overweight and 30 obese individuals, each between ages 18-30 years were selected from student population, VIMS, Bellary and also from general population to find out electrocardiographic changes in relation to body mass index. The ECG was recorded and was evaluated for different parameters like heart rate, P wave, PR interval, QRS complex, QRS axis, QT interval, QTcinterval, and results were drawn. Results: There was statistically significant increase in heart rate, PR interval, QT interval, QTc interval, in overweight and obese individuals when compared to normal individuals and decrease in QRS axis in overweight and obese individuals when compared to normal individuals. Conclusions: The study shows that there are a variety of adaptations/alterations in cardiovascular system with increase in body mass index which bring about changes in ECG in the absence of any cardiac disease.

Keywords: ECG; Body mass index; Physiological changes.