Changes in Heart Rate Variability Parameters after Elective Percutaneous Coronary Intervention

Background: Patients with chronic stable angina often have a state of sympathetic hyperactivity. It is considered associated with myocardial ischemia and disappears after ischemia elimination. The aim of this study was to investigate the changes in heart rate variability parameters, a noninvasive technique for the evaluation of the autonomic nervous system activity, after successful revascularization in these patients to evaluate this theory. Methods: The patients were enrolled among those who underwent successful percutaneous coronary intervention. Short-term heart rate variability analyses of all the patients were obtained, and time-domain indices (standard deviation of normal-to-normal intervals [SDNN], standard deviation of differences of successive R-R intervals [SDSD], root-mean square differences of successive R-R intervals [rMSSD], percentage of R-R intervals differing > 10 ms from the preceding one [PNN(10)], percentage of R-R intervals differing > 20 ms from the preceding one [PNN(20)], percentage of R-R intervals differing > 30 ms from the preceding one [PNN(30)], percentage of R-R intervals differing > 40 ms from the preceding one [PNN(40)], percentage of R-R intervals differing > 50 ms from the preceding one [PNN(50)], percentage of R-R intervals differing > 60 ms from the preceding one [PNN(60)], and percentage of R-R intervals differing > 70 ms from the preceding one [PNN(70)]) were analyzed. All the measurements were made before and after percutaneous coronary intervention. Results: This study included 64 patients, comprising 27 men and 37 women at a mean age of 56.8 ± 9.1 years. There was a significant difference only between pre- and post-revascularization SDNN (27.5 ± 19.72 vs. 41 ± 41.4; p value = 0.013). The other parameters showed no significant differences after successful coronary intervention. Conclusion : Our data indicate that the increase in SDNN in patients with stable angina pectoris undergoing percutaneous coronary intervention seems to be prominent.