A simple pacing maneuver to unmask an epicardial connection involving the right‐sided pulmonary veins

Abstract

Introduction An epicardial connection (EC) between the right‐sided pulmonary venous (PV) carina and right atrium (RA) is one of the mechanisms for which carinal ablation is required for right‐sided PV isolation. The purpose of the study was to devise a simple pacing maneuver to differentiate an EC from a residual conduction gap on the antral ablation line during radiofrequency catheter ablation. Methods and Results This study included 133 consecutive patients. After one round of ablation, electrograms at the posterior antrum outside the ablation line were recorded during sinus rhythm (SR) and coronary sinus (CS) pacing, and intervals between the antral and PV potentials were measured in each rhythm. The ΔintervalSR‐CS was calculated as the difference between the interval during SR and that during CS pacing. Presence of an EC was confirmed by observation of a RA posterior wall breakthrough during right‐sided PV pacing, which was then targeted for ablation. Patients with nonachievement of first‐pass isolation (N = 35) and with PV reconnection during the procedure (N = 9) were classified into the EC‐group (N = 20) and gap‐group (N=24), respectively. The prevalence of carina breakthrough during SR was higher in the EC‐group than the gap‐group (18 [95%] vs. 1 [4%] patients, p < .0001). The ΔintervalSR‐CS was larger in the EC‐group versus gap‐group (71 [interquartile range, 57–97] vs. 6 [2–9] ms, p < .0001). In all patients with an EC, RA ablation resulted in delay (32 [20–40] ms) (N = 15) or elimination of PV potentials (N = 5). Conclusion An EC can be efficiently discriminated from a conduction gap by a simple pacing maneuver.

An Epicardial Connection With a Unidirectional Conduction Property From the Left Atrium to Pulmonary Vein

“…Recent studies have suggested the presence of an epicardial connection involving the PVs as one of the mechanisms for failure of isolation by circumferential lesion sets. 1 , 2 , 3 , 4

Learning Objectives

To recognize the presence of epicardial connections as a possible cause of failure of first-pass isolation. To recognize an epicardial connection between the pulmonary veins and the left atrium in addition to Marshall bundle and coronary sinus musculature.

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Distinct propagation patterns of right pulmonary veins through multiple epicardial connections during right atrial pacing and sinus rhythm

“…A wide area circumferential ablation (WACA) at the antrum has increasingly replaced the pulmonary vein (PV) ostial ablation because of a higher success rate and reduced risk of PV stenosis 1 . However, epicardial connections with intercaval fibers between the right atrium (RA) and right pulmonary vein (RPV) can bridge the WACA lesions, which could lead to a challenging RPV antral ipsilateral isolation only with a continuous linear ablation encircling the RPV 2,3 …”

“…The earliest activation was observed at the anterior RIPV inside the WACA, which was identical to the LA breakthrough during RA pacing distant from the WACA line (Figure 2A,C). Pacing maneuvers 2 to differentiate epicardial connections from gaps on the WACA line (The Δinterval SR‐CS at posterior antrum was 94 ms), suggested there was an epicardial connection. Once the RPV was isolated by an RF application at that epicardial connection (Epi‐connection 2 in Figure 1), an acute reconnection occurred again (the earliest activation was found on the anterior carina [Epi‐connection 1 in Figure 1], which was the LA breakthrough site during sinus rhythm far from the WACA line; Figure 2B,D).…”

Epicardial Connections as Intra-Atrial Conduction Routes in a Patient With Advanced Atrial Remodeling

“…Spontaneous recovery of the PQ interval was noted after cardioversion. Although PV potentials were found in the RtPV carina, gap conduction was unlikely, on the basis of careful PV antral mapping and the pacing study ( 8 ). Thus, we decided to create an activation map of the RA during pacing from a LASSO catheter (Biosense Webster, Inc.) placed in the right superior PV ( 5 , 8 ).…”

“…Although PV potentials were found in the RtPV carina, gap conduction was unlikely, on the basis of careful PV antral mapping and the pacing study ( 8 ). Thus, we decided to create an activation map of the RA during pacing from a LASSO catheter (Biosense Webster, Inc.) placed in the right superior PV ( 5 , 8 ). The earliest activation site was found in the right atrial posteroseptal wall ( Figure 2A ), and ablation of that site achieved RtPV isolation ( Figure 2B ).…”