Effect of Physical Stress on Heart Rate Variability (HRV) in Subjects of Type 'A' and Type 'B' Personality: A Comparative Interventional Study

Background: Stress is an individual's inability to cope up with the altered situation. The stress may be mental or physical or both. Stress up to an optimal level is necessary to achieve the target but prolonged stress may result in illness. Individual's capacity to react with stress is varied and depends on their personality. The stress influences our autonomic functions that can be measured in term of heart rate variability (HRV). So this study is conducted to compare the effect of physical stress in subjects of Type 'A' and Type 'B' personality. Methodology: For this study, 30 participants of Type 'A' and 30 of Type 'B' personality 18-30 years aged subjects were taken. In all participants, HRV was recorded during resting state (baseline) and after physical stress for five minutes, for short-term analysis. The physical stress was subjected to 45-degree shoulder abduction of one arm with maximum extension. Results: The raised baseline heart rate was observed in Type 'A' than Type 'B' personality subjects. When the physical stress was applied, the sympathetic parameters (LF, LF: HF ratio) was decreased and the parasympathetic parameter (HF) was increased in Type 'A' whereas in Type 'B' personality subjects parasympathetic parameter (HF) was increased and sympathetic parameters (LF) was decreased. Conclusions: The physical stress is good for Type 'A' personality subjects as their parasympathetic activity are raised, while the Type 'B' personality subjects are unable to cope up with physical stress as they present raised sympathetic activity.