Autonomic imbalance is known to play a key role in health and disease. However, there is a lack of data exploring the sympathovagal balance across the lifecycle among the healthy Asian Indians Objective: To compare the changes in HRV (Heart rate variability) indices among clusters of the healthy population across the life cycle. Methods: Analysis was performed on pooled data categorised into 4 study groups including fetal (n=90), child (n=90), young adult (n=134), and old (n=85). ECG was

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... ed and subjected to HRV power spectral analysis. Results: There was a significant difference in all log-transformed HRV indices between the study groups (p<0.01). Low frequency (LF) and high frequency (HF) HRV indices were lower in the fetal and the older adult group compared to the child and young adult (p<0.01). Effect size (Cohen's d) estimates for fetal and young adult groups for LF was 2.9 and that for HF was higher at 3.4. The effect size between young adult and old groups was 1.7 for LF and 2.1 for HF Conclusion: There was an increment in HRV indices reflecting the maturity of cardiac vagal and cardiac sympathetic control of the heart from fetal to adult life. The degree of modulation across age groups was greater for the parasympathetic compared to the sympathetic component.