Association between QTc and Poincare plot in polycystic ovary syndrome in young adolescents: A cross-sectional study.

Abstract

PCOS is one of the most neglected noncommunicable diseases, and early detection would be of great value to primary care physicians. Sympathovagal imbalance detected using heart rate variability (HRV) can be used to detect early autonomic changes if any. The present study aimed to evaluate QTc and Poincare plot (nonlinear analysis of HRV) in young adolescent PCOS patients. It was a cross-sectional study involving 25 PCOS and 25 healthy individuals of age group 12-18 years. HRV was evaluated using the lead II ECG for 10 min from which QTc was calculated manually using the Bazett formula. Student's <i>t</i>-test was used to assess differences between means. A <i>P</i> value < 0.05 was taken for statistical significance. The association between QTc and Poincare plot descriptors was assessed by Pearson's correlation analysis. HRV linear analysis domain represented as the LF/HF ratio was reported to significantly increased among the PCOS group (<i>P</i> = 0.04). Similarly, the nonlinear analysis of HRV by Poincare plot reported a significant decrease in SD1 (<i>P</i> = 0.04) and SD2 (<i>P</i> = 0.02). The heart rate was significantly increased among the PCOS group (<i>P</i> < 0.001). QTc did not show any significant increase among the PCOS group (<i>P</i> = 0.09). QTc was reported to be positively correlated with SD1 (r = 0.37, <i>P</i> < 0.01), SD2 (r-0.33, <i>P</i> = 0.02), LF HF ratio (r = 0.52, <i>P</i> < 0.001), and BMI (r = 0.92, <i>P</i> < 0.001), respectively. The study suggests that HRV nonlinear analysis can be used as a simple noninvasive tool to evaluate cardiovascular autonomic changes.