The reinnrevation with pulmonary vein isolation associated cardiac autonomic dysfunction

Abstract Background It is well-known that cardiac autonomic nerve is impaired after Pulmonary vein isolation (PVI) for atrial fibrillation (Af), but the the long-term change in cardiac autonomic function is unclear. Objective We followed the long-term cardiac autonomic nervous function after PVI and clarified its recoverability. Subjects Of 136 patients who received 1st session PVI from 2013 to 2017, 49 patients [Male: 86%, 62±11y, Diabetes meritus: 16%, radiofrequency (RF) ablation: 59%, cryoballoontechnique (Cryo): 41%, left atrial diameter: 37.2±4.5mm, LVEF: 67.4±9.7%, BNP: 103±108pg/dl]who satisfied the Inclusion criteria (No history of cardiac surgery, no recurrence of Afafter PVI for more than 1 year, with Holter ECG record of sinus rhythm before PVI and every 3 months after PVI for 1 year or more. Method Heart rate variability (HRV) parameters for each period (before PVI and after PVI 0–3 months, 3–6 months, 6–9 months, 9–12 months) were obtained from each Holter ECG records using MemCalcsystem. We defined the HRV before PVI as 100% and examined the rate of change for each HRV (see Figure) after PVI retrospectively. Result All of HRV indicators after PVI had been decreased significantly at 0–3 months after PVI (from 21.7% to maximum of 77.9% down). Figure is a series of indexes from front to back in order of decreasing HRV at 0–3 months after PVI, and the frequency domain index concentrates on the front. These decreased HRVs gradually recovered through 12 months after PVI (shown in figure left), but this change is more responsive in the frequency domain index than in the time-domain index, and after 3–6 months, all indices has already showed a significant rise compared with 0–3 months after PVI. In any of the indices, this increase over time did not receive interaction due to the difference in the procedure (RF, Cryo). Conclusion HRV decreased by PVI showed a significant rise over time, mainly in the frequency domain, at 3–6th month after PVI, suggesting the existence of reinnervation of cardiac autonomic nerve at this period.