Short-term HRV metrics as a method for intraoperative assessment of cardiac parasympathetic response to rapid atrial pacing

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.