Vagal response during radiofrequency catheter ablation initiated from right superior pulmonary vein: Incidence, risk factors, and clinical outcomes

Background: The vagal response (VR) is unavoidable during pulmonary vein isolation (PVI) for atrial fibrillation (AF). In this study, we aimed to investigate the incidence, risk factors, and clinical outcomes of VR during PVI initiated from the right superior pulmonary vein (RSPV).

Methods: Patients with AF were consecutively enrolled. PVI was initiated from the RSPV, followed by other PVs. The VR was defined as atrioventricular block (AVB), asystole, or a 50 % increase in the R-R interval.

Results: We enrolled 702 patients with AF (paroxysmal = 380, persistent = 322). Seventy-seven (11.0 %) patients developed 81 VR episodes, which were more common in paroxysmal than persistent AF (74 [19.5 %] vs. 3 [0.9 %], P < 0.001). VR manifestations in paroxysmal AF included sinus arrest in 51 (63.0 %) patients, sinus bradycardia in 26 (32.1 %), and AVB in one (1.2 %) patient. For persistent AF, VR manifested as AVB. Most VR episodes were observed in the left superior ganglionated plexi (n = 67, 82.7 %). Body mass index (BMI) ≥28.0 kg/m² (odds ratio [OR] = 2.261, P = 0.005) and left ventricular ejection fraction (LVEF) ≥60.0 % (OR = 2.622, P = 0.018) were independent risk factors. Among patients with paroxysmal AF, seven (9.5 %) with VR and 34 (11.1 %) without VR had AF recurrence during a follow-up of 15.5 ± 4.6 months (P = 0.582).

Conclusions: VR occurred more often in paroxysmal AF than in persistent AF during RSPV-initiated PVI, with specific manifestations. Increased BMI and LVEF were independent risk factors. Inadvertent VR does not predict better clinical outcome.