ABSTRACT
Introduction: Menstrual cycle is a physiological cyclical occurrence in women. This is associated with variations in metabolism and associated endocrine fluctuations. Among other things, the cardio respiratory changes too have been observed. In the present study, we investigated the autonomic control of heart, and concurrent changes in the respiratory system. Material and methods: Forty seven normally menstruating women were recruited from a group of 80 subjects reported for this study voluntarily. ECG was recorded from limb lead II time domain and frequency domain analysis of Heart rate Variability (HRV) was done. Their respiratory parameters namely PEFR, FEV1 were determined. Results: The results of this study were analysed by applying Wilcoxon’s signed rank sum test. In Time domain analysis RMSSD (36.91±2.73, p<0.05) showed significant decrease during ovulation, while other parameters did not show significant variation among the three phases. Frequency domain analysis yielded results to suggest that there is increased variability during Ovulatory and Luteal phase (p<0.05). PEFR and FEV1 increased in luteal phase (p<0.05).Conclusions: The results of our study reiterated the findings of reports of previous studies on the heart rate variability suggesting that the HRV was more during ovulatory and luteal phase. This is suggestive of the role of Progesterone on the HRV. Similarly the respiratory parameters too showed an increased PEFR and FEV1 suggesting a decreased airway resistance, while other parameters remained unchanged.