Pulmonary Vein Region Ablation in Experimental Vagal Atrial Fibrillation

Abstract

Background-Pulmonary vein (PV) -encircling radiofrequency ablation frequently is effective in vagal atrial fibrillation (AF), and there is evidence that PVs may be particularly prone to cholinergically induced arrhythmia mechanisms. However, PV ablation procedures also can affect intracardiac autonomic ganglia. The present study examined the relative role of PVs versus peri-PV autonomic ganglia in an experimental vagal AF model. Methods and Results-Cholinergic AF was studied under carbachol infusion in coronary perfused canine left atrial PV preparations in vitro and with cervical vagal stimulation in vivo. Carbachol caused dose-dependent AF promotion in vitro, which was not affected by excision of all PVs. Sustained AF could be induced easily in all dogs during vagal nerve stimulation in vivo both before and after isolation of all PVs with encircling lesions created by a bipolar radiofrequency ablation clamp device. PV elimination had no effect on atrial effective refractory period or its responses to cholinergic stimulation. Autonomic ganglia were identified by bradycardic and/or tachycardic responses to high-frequency subthreshold local stimulation. Ablation of the autonomic ganglia overlying all PV ostia suppressed the effective refractory period-abbreviating and AF-promoting effects of cervical vagal stimulation, whereas ablation of only left-or right-sided PV ostial ganglia failed to suppress AF. Dominant-frequency analysis suggested that the success of ablation in suppressing vagal AF depended on the elimination of high-frequency driver regions. Conclusions-Intact

2012 HRS/EHRA/ECAS Expert Consensus Statement on Catheter and Surgical Ablation of Atrial Fibrillation: Recommendations for Patient Selection, Procedural Techniques, Patient Management and Follow-up, Definitions, Endpoints, and Research Trial Design

“…103,105,114,116,124,355,576,577,578,579,580,581,582 Because the GP are consistently located within areas of highly fractionated atrial potentials (FAPs), also referred to as CFAEs, 103,105,114,116,124,355,576,577,578,579,580,581,582,583,584 it is useful to begin with a fractionation map of the LA and PVs during AF. The LA FAPs are usually located in four areas: (1) LAA ridge FAP area (between LAA and left PVs); (2) superior left FAP area; (3) inferoposterior FAP area; and (4) anterior right FAP area (Figure 4).…”

Differences in atrial fibrillation properties under vagal nerve stimulation versus atrial tachycardia remodeling

“…An interesting correlation of CFAEs with DFs and consequently vagal ganglia was also suggested by the electroanatomical mapping performed in our study. Therefore, based also on previous observations 72,73,138,143 , ablation of vagal ganglia during AF ablation could also be advantageous.…”

“…Our results are similar to previous work where AFCL was examined 71,117 . Moreover, recent studies showed high DF values after electric or ACh induced stimulation of cardiac autonomic ganglia 38,53,73,134,135 . However, to our knowledge this is the first study comparing the spectral properties of VS AF with ATR AF.…”

Combined Effect of Pulmonary Vein Isolation and Ablation of Cardiac Autonomic Nerves for Atrial Fibrillation

“…Relation of GP ablation to outcome: Catheter ablation of GP has been shown to prevent vagal AF in canine models. 8,11,21) In recent clinical studies, vagal denervation was induced by targeted GP ablation 9,11,13,17) or inadvertently by standard circumferential or segmental PVI. 16,22) However, only limited data have been available on the long-term benefit of vagal denervation.…”