Analysis of Poincare plot of heart rate variability in the assessment of autonomic dysfunction in patients with polycystic ovary syndrome

Background and Aim: Polycystic ovary syndrome (PCOS) due to its constant association with obesity poses a significant cardiovascular (CV) risk. Heart rate variability (HRV) has been a noninvasive marker of autonomic dysfunction and CV risk. This study was designed to assess the nonlinear dynamics of HRV using Poincare plot in patients with PCOS and elucidate its importance in predicting the CV risk. Methods: A total of 45 women with newly diagnosed PCOS and 45 controls were recruited for the study. Waist-hip ratio, body mass index (BMI), basal CV parameters such as basal heart rate (BHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and rate pressure product (RPP) were recorded. HRV analysis was done using both linear (time domain and frequency domain) and nonlinear measures (Poincare plot). Results: The cases had increased basal heart rate, BMI, SBP, DBP, MAP, and RPP. In linear measures of HRV, the total power (TP), which depicts overall HRV was reduced, and the ratio of low-frequency to high-frequency (LF-HF) was significantly increased in cases. In nonlinear measures, the standard descriptors (SD1 and SD2) and area of the ellipse (S) were decreased, which signifies decreased HRV. There was a significant correlation of linear measures (TP, LF-HF ratio) and nonlinear measures (SD1, SD2, S) with elevated RPP. Both linear and nonlinear measures had independent contribution to elevated RPP, observed from regression analysis. Conclusion: Decreased HRV and autonomic dysfunctions in the form of increased sympathetic drive and decreased vagal activity were observed in PCOS patients that may herald CV risks. Poincare plot analysis can independently quantify the magnitude of autonomic dysfunction in PCOS.