Abstract

Background: Electrocardiogram (ECG) waveforms are influenced by physiological, pathological, and psychological factors. Acute mental stress affects the hypothalamic–pituitary–adrenal axis resulting in alterations in various physiological functions of the body particularly the cardiovascular system.

Objective: To study the ECG changes during acute mental stress and also to understand the reasons for the changes in ECG caused by acute mental stress.

Materials and Methods: ECG was recorded in relaxed state and in acute stress state in healthy male subjects in the age group of 18–24 years. ECG recordings in relaxed state were compared with those in acute stress state.

Result: Increased heart rate, decreased PR interval, decreased QT interval, and prolonged QTc interval were observed in ECGs in acute stress state which were statistically significant. Also an increase in QRS duration and change in QRS axis were observed during acute stress which were statistically not significant.

Conclusion: Increased sympathetic activity caused by acute mental stress may be the cause for this altered electrical activity of the heart.

Key words: ECG; acute stress; sympathetic activity; vagus nerve