ABSTRACT
Objectives: Heart rate variability (HRV) is the beat-to-beat variation of heart rate and an important non-invasive tool to study the cardiac autonomic nervous system activity. Ischaemic heart disease (IHD) patients are often considered to have a state of sympathetic predominance. Elimination of myocardial ischaemia with percutaneous coronary intervention (PCI) could restore autonomic balance. Hence, this study aimed to evaluate HRV measures, after successful revascularisation among IHD patients. Materials and Methods: A total of 145 male IHD patients planned for coronary angiography were recruited. Fifteen minutes of electrocardiogram recording was done. Short-term HRV analyses of all the patients were acquired and time-domain indices (standard deviation of normal-to-normal intervals [SDNN], root-meansquared differences of successive R-R intervals [rMSSD]) and frequency-domain indices (low-frequency [LF] power, high-frequency [HF] power and total power [TP]) were analysed. Before and after PCI, all measurements were made. Results: This study included 145 male IHD patients with the mean age of 54.57 ± 10.81 years. There was a significant decrease in SDNN, rMSSD, LF, HF and TP whereas increase in LF/HF ratio following revascularisation. These changes in measures of neurocardiac regulation correlated with risk factors and medication on regression analysis. Conclusion: Increase in LF/HF ratio with the decrease in SDNN, rMSSD, LF, HF and TP in patients with IHD who underwent coronary intervention infers changed cardiac autonomic balance with this surgical procedure. These measures could be potentially used as prognostic measures in the future studies.