Assessment of cardiovascular autonomic dysfunction in untreated adult hypothyroid patients

Abstract

Introduction and Aim: Hypothyroidism is an endocrine disorder with a high prevalence worldwide in the adult population. Due to the thyroid hormone’s widespread role in controlling metabolic processes to permissive action on the heart, patients with hypothyroidism suffer from a significant chance of acquiring cardiac autonomic dysfunction which further deteriorates the prognosis. Heart rate Variation analysis can be a possible way to detect this autonomic dysfunction early and may help in patient care. This study aims to assess Heart Rate Variability (HRV) parameters in untreated overt hypothyroid patients and compare the parameters of heart rate variability test with an age and sex-matched healthy control group. Materials and Methods: With the permission from the institutional ethics committee, 50 untreated hypothyroid patients are collected from the endocrine outpatient department and 50 healthy age, sex, and matched individuals are taken, maintaining proper inclusion and exclusion criteria. HRV analysis data is collected in both time and frequency domains in both groups and compared using statistical tools. Results: In our research, it is seen that compared to healthy control group, untreated hypothyroid patients have a significant alteration in the following parameters - SDNN (p<0.005) and RMSSD (p<0.009) in the time domain and LF (nu), LF (%), HF (%), LF/HF, HF (nu)[p<0.05] in the frequency domain. Conclusion: Due to several alterations in HRV parameters indicating sympathovagal disbalance in the hypothyroid patients, it can be concluded that untreated hypothyroid patients are prone to develop cardiovascular autonomic dysfunction and HRV analysis can be a possible way to detect it early.