Effect of Reperfusion on Time Domain Parameters of Heart Rate Variability

Objective: To compare effect of reperfusion by measuring time domain parameters of heart rate variability before and after percutaneous transluminal coronary angioplasty. Study design: Quasi experimental study design Place and Duration: Department of Clinical Cardiac Electrophysiology, Armed Forces Institute of Cardiology/National Institute of Heart Diseases (AFIC/NIHD), Rawalpindi from January 2014 till January 2015. Patients and Methods: 40 patients with coronary artery disease having mean age of 55.20 ± 8.03 years were recruited by non-probability convenience sampling. DMS 300-4A Holter monitors were used to obtain 24 hours ambulatory ECG recording before and within 24 hours after percutaneous transluminal coronary angioplasty. Digital ECG data were transferred to the computer and edited with the help of DMS Cardioscan software. Heart rate variability was analysed in time domains measures. For time domain analysis normal heart rate, SDNN, SDNNi, SDANN, RMSSD and pNN50 were recorded from 12 lead digital ECG data. Results: The results of our study demonstrated significantly decreased heart rate variability in coronary artery disease patients on comparison of pre and post-angioplasty values only SDNNi was significantly reduced (p-value = 0.035) whereas the reduction in SDNN and pNN50 was statistically insignificant (p-value > 0.05). On the contrary, SDANN and RMSSD displayed slight rise after angioplasty but it was not significant (p-value > 0.05). Conclusion: Reperfusion after percutaneous transluminal coronary angioplasty decreases heart rate variability within 24 hours after the procedure. Whereas, heart rate during the same period after angioplasty increases. This reflects autonomic balance shifts towards sympathetic predominance as indicated by reduced heart rate variability and rise in heart rate. This makes the susceptible patients vulnerable for development of ventricular arrhythmias especially during 24 hours after angioplasty. Therefore, patients with decreased heart rate variability are at risk of ventricular arrhythmogenesis so they may be kept under medical surveillance for at least 24 hours after percutaneous transluminal coronary angioplasty.