Rapid atrial pacing at 100 bpm for 30 seconds increased RMSSD from 15.7 ms to 41.7 ms and ΔPP from 33 ms to 90 ms (both p < 0.001), indicating a robust intraoperative parasympathetic response in adults without structural heart disease undergoing electrophysiological study.
Observational (n=50)
No
Does rapid atrial pacing induce measurable short-term changes in heart rate variability (RMSSD and ΔPP) in patients without structural heart disease undergoing electrophysiological study?
Rapid atrial pacing evokes a robust, repeatable parasympathetic response detectable intraoperatively using ultra-short HRV metrics (RMSSD and ΔPP), offering a potential real-time method to assess vagal modulation during electrophysiological procedures.
Effect estimate: p < 0.001 (Wilcoxon signed-rank test) for RMSSD increase; ΔPP median increased from 33 ms before pacing to 90 ms after pacing, p < 0.001
Absolute Event Rate: 41.7% vs 15.7%
p-value: p=<0.001
Introduction Heart rate variability (HRV) is widely used to assess parasympathetic influence on cardiac function and has proven useful in evaluating long-term autonomic effects of cardioneuroablation (CNA). However, HRV has not yet been used intraoperatively to quantify dynamic, short-term changes in parasympathetic tone. Rapid atrial pacing (AP) is expected to provoke a brief parasympathetic reaction, but no standardized method exists to assess this response in real time during electrophysiological procedures. Aims To evaluate HRV changes induced by rapid AP using RMSSD and the maximal-minimal PP interval difference (ΔPP), and to assess the feasibility of repeated intraoperative monitoring. Methods This prospective observational study enrolled 50 patients (median age 39 years IQR 31-52) without structural heart disease referred for electrophysiological study. RMSSD and ΔPP were calculated from four PP intervals before pacing and reassessed immediately after 30-s atrial pacing at 100 bpm. Heart rate, Sinus node recovery time, cSNRT and Wenckebach point were also measured. All measurements were repeated 2 minutes later. Results Rapid AP produced a significant increase in RMSSD (15.7 ms 9.7–23.7 vs. 41.7 ms 25.6–59.6, p 0.001) and ΔPP (33 ms 19-56 vs. 90 ms 60-152, p 0.001). The response was reproducible in the second pacing sequence (RMSSD 13.6→41.0 ms; ΔPP 24→107 ms; both p 0.001; Wilcoxon signed-rank test with Bonferroni correction). HRV changes occurred independently of sinus cycle length modifications. No significant differences were observed in SNRT, cSNRT, or Wenckebach point. Conclusion Rapid AP evokes a robust, repeatable parasympathetic response detectable using ultra-short HRV metrics-expressed as an increase in RMSSD and ΔPP. These parameters allow real-time intraoperative assessment of parasympathetic influence on the sinus node. This approach warrants validation in future studies involving CNA, atropine challenge, and ECVS.
Skoczyński et al. (Thu,) conducted a observational in Adults with palpitations without structural heart disease, normal sinus node function, and no atrioventricular conduction abnormalities undergoing invasive electrophysiological study (n=50). Rapid atrial pacing (AP) vs. Baseline sinus rhythm before pacing was evaluated on Change in short-term heart rate variability (HRV) metrics RMSSD and ΔPP (difference between longest and shortest PP intervals) before and after rapid atrial pacing (p < 0.001 (Wilcoxon signed-rank test) for RMSSD increase; ΔPP median increased from 33 ms before pacing to 90 ms after pacing, p < 0.001, p=<0.001). Rapid atrial pacing at 100 bpm for 30 seconds increased RMSSD from 15.7 ms to 41.7 ms and ΔPP from 33 ms to 90 ms (both p < 0.001), indicating a robust intraoperative parasympathetic response in adults without structural heart disease undergoing electrophysiological study.