B-PO05-138 CATHETER ABLATION OF ATRIAL FIBRILLATION IS NOT ASSOCIATED WITH DESTRUCTION OF CARDIAC AFFERENTS DRIVING VOLUME-REGULATING AUTONOMIC REFLEXES

Abstract

We have previously shown abnormal cardiac volume-sensitive reflexes (whose receptors are co-located in veno-atrial tissue) in AF patients. Whether unintended nerve disruption from Pulmonary Vein Isolation (PVI) could also occur is unknown. To evaluate whether PVI disrupts afferent volume-sensitive reflexes. We consecutively studied paroxysmal/persistent AF patients pre-PVI (n =18) and recontacted them for a post-PVI visit. We excluded those with AF recurrence/procedural complications, allowing redo procedures if AF-free >6 months. A cohort of 9 patients consented to both visits. We measured beat-to-beat mean arterial pressure (MAP) and heart rate (HR) continuously while testing reflex vasoconstriction from Lower Body Negative Pressure (LBNP), which offloads veno-atrial volume receptors, using forearm blood flow (FBF∝1/vascular resistance), at 0, -20 & -40 mmHg LBNP by venous occlusion plethysmography. We withheld anti-hypertensives/arrhythmics (5 half-lives). Mean age was 64±3 years; 78% male; BMI 28±1 kg/m2; LA size 37±2 ml/m2; and left ventricular function 65±3 %. We performed single ring radiofrequency PVI (PV and posterior wall, n=7); cryoablation (n=1) and wide antral PVI (n=1). Redo in n=2. During LBNP, MAP decreased slightly both pre (-1.6±3%) and post-PVI (-2.8±1.8%); P=0.7. HR increased similarly (P=0.7) pre (10.6±6.4%) and post-PVI (7.2±1.5%). FBF was unchanged (P=0.8), Figure. The reflex response to decreased cardiac volume is not altered by PVI. More work to assess other lesion sets or ganglionated plexi ablation is needed to ensure absence of adverse autonomic remodelling due to catheter ablation for AF.