Effect of slow breathing exercise on heart rate variability in tension-type headache female patients: A time domain analysis

Background: Tension-type headache (TTH), the most frequently occurring primary headache is associated with autonomic dysfunction. Time domain analysis of heart rate variability (HRV) is a popular tool to detect changes in cardiac autonomic nerve function (CANF) in TTH patients. Slow breathing exercise (SBE) can significantly improve HRV in patients with cardiovascular disorders. Objective: To observe the effect of SBE on HRV by time domain analysis in TTH female patients. Methods: This quasi-experimental study was conducted from March 2021 to February 2022 in the Department of Physiology, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka on 60 female TTH patients aged 20-45 years. Thirty patients performed SBE every morning and evening for 30 minutes in addition to receiving conventional treatment and 30 patients continued only conventional treatment without any exercise for 90 days. Thirty age, sex and BMI matched apparently healthy control were enrolled who did not perform SBE or any other exercise. All subjects were assessed at baseline and also after 90 days. Time domain HRV parameters were recorded by Power Lab 8/35 AD Instruments, Australia. One way ANOVA followed by post-hoc test and Paired sample t-test were performed for statistical analysis and p