Effect of mental stress on autonomic nervous function in young adults

Introduction: Autonomic imbalance is one of the important pathways through which psychological stress contributes to cardiovascular diseases/sudden death. Stress is a normal physical response to events that make us feel threatened or upset our balance in some way. There is a major role of mental stress in provoking silent myocardial ischemia, cardiac arrhythmia, catecholamine induced increase in heart rate, increase in blood pressure that result in enhanced myocardial oxygen demand and sometimes sudden death. In this study an attempt is made to study the variations in electro cardiogram (ECG) after inducing mental stress in normal subjects. Materials and Methods: The study included 50 healthy medical students in the age group of 18-25 studying in VIMS, Bellary. Following an explanation about the nature and purpose of the study, those subjects who are willing to participate were included after obtaining their consent. Blood pressure and ECG was recorded at rest in supine position. Then mental stress was induced on each by a no. of mental tasks and ECG was recorded in them immediately. The stressed subjects were evaluated with Speilberger’s State and Trait Anxiety Inventory (STAI) score. Blood pressure and ECG results were evaluated for different parameters and the data collected was tabulated and subjected to statistical analysis. Results: There was statistically significant increase in heart rate, systolic BP, diastolic BP, decrease in PR interval and QRS interval, increase in QTc interval, T wave pattern changes, ST segment depression found after inducing mental stress. Conclusion: The study shows that there were varieties of ECG changes in mental stress that may affect the health of human beings.