Electrical connection between ipsilateral pulmonary veins : prevalence and implications for ablation and adenosine testing.

BACKGROUND: Anatomic studies have reported the presence of shared myocardial fibers between approximately half of ipsilateral pulmonary veins (IPVs). OBJECTIVE: The purpose of this study was to assess the prevalence of electrical connection between IPVs and the impact of antral isolation with or without carina ablation on IPV connection. METHODS: Thirty consecutive patients undergoing atrial fibrillation (AF) ablation (14 redo) were included. Wide antral pulmonary vein isolation (PVI) was performed with or without carina lesions. For each PV set, IPV electrical connection was assessed before and after PVI by pacing and recording from the ostium of both IPVs using a circular mapping catheter and the ablation catheter. Adenosine was given after PVI to assess for acute PV reconnection. RESULTS: Before PVI without preceding AF ablation procedure, all the PVs had ipsilateral connection albeit frequently via the left atrium. After PVI, 65.6% of the IPVs were connected without carina ablation vs 17.7% if prior carina ablation (P = .001). Left vs right IPVs were connected in 57.1% and 72.2% of the cases without carina ablation, respectively, vs 30% and 0% of cases with carina ablation (P = .19 and P = .001). When transient PV reconnection was demonstrated during adenosine challenge, connected IPVs uniformly demonstrated simultaneous reconnection. CONCLUSION: Electrical connection between IPVs is uniformly demonstrated before any ablation. Two-thirds of the IPVs are connected after antral PVI, and carina ablation decreases IPV connection. Connected IPVs consistently show the same response to adenosine challenge; therefore, a single catheter positioned in either of the IPVs with electrical connection is sufficient to confirm reconnection in both veins.