Differences between gap-related persistent conduction and carina-related persistent conduction during radiofrequency pulmonary vein isolation

Abstract

Background: During pulmonary vein isolation (PVI), nonisolation after initial encircling of the pulmonary veins (PVs) may be due to gaps in the initial ablation line, or alternatively, earliest PV activation may occur on the intervenous carina and ablation within the wide-area circumferential ablation (WACA) circle is needed to eliminate residual conduction. This study investigated prognostic implications and predictors of gap-related persistent conduction (gap-RPC) and carina-related persistent conduction (carina-RPC) during PVI.

Methods and results: Two hundred fourteen atrial fibrillation (AF) patients (57% paroxysmal, 61% male, mean age 62 ± 9 years) undergoing first contact force-guided radiofrequency PVI were studied. Preprocedural cardiac computed tomography imaging was used to assess left atrial and PV anatomy. PVI was assessed directly after initial WACA circle creation, after a minimum waiting period of 30 minutes, and after adenosine infusion. Persistent conduction was targeted for additional ablation and classified as gap-RPC or carina-RPC, depending on the earliest activation site. The 1-year AF recurrence rate was higher in patients with gap-RPC (47%) compared to patients without gap-RPC (28%; P = .003). No significant difference in 1-year recurrence rate was found between patients with carina-RPC (37%) and patients without carina-RPC (31%; P = .379). Multivariate analyses identified paroxysmal AF and WACA circumference as independent predictors of gap-RPC, whereas carina width and WACA circumference correlated with carina-RPC.

Conclusions: Gap-RPC is associated with increased AF recurrence risk after PVI, whereas carina-RPC does not predict AF recurrence. Moreover, gap-RPC and carina-RPC have different correlates and may thus have different underlying mechanisms.

Keywords: atrial fibrillation; carina; catheter ablation; persistent conduction; pulmonary vein isolation.

Figure 1

CT image analysis. A, Three‐dimensional reconstruction of the left atrium (LA) and pulmonary veins (PV) allows for assessment of global PV anatomy. B, PV diameters were obtained after orienting a view perpendicular to the centerline of the PV. C, Carina width, defined as the distance between ipsilateral superior and inferior PV ostia, was measured on the reconstruction of the LA. D, After cutting off left PVs and left atrial appendage (LAA), the average width of the PV‐LAA ridge was calculated by averaging measurements on the level of left superior PV, carina and left inferior PV. CT, computed tomography; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein

Figure 2

Schematic illustration of WACA segments and measurement of WACA circumference. Schematic illustration showing left (L) and right (R) wide‐area circumferential ablation (WACA) and measurement of WACA circumference. Yellow tags represent additional ablation of carina‐related persistent conduction (carina‐RPC) in the left WACA and additional ablation of gap‐related persistent conduction (gap‐RPC) in the right WACA. Mean/minimum contact force and impedance drop were recorded for each ablation lesion tag and all tags were categorized according to a 16‐segment model. A, anterior; AI, anterior inferior; AS, anterior superior; carina‐RPC, carina‐related persistent conduction; I, inferior; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; P, posterior; PI, posterior inferior; PS, posterior superior; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein; S, superior; WACA, wide‐area circumferential ablation

Figure 3

Kaplan‐Meier survival analyses for freedom of atrial tachyarrhythmias. Kaplan‐Meier survival analyses for freedom of atrial tachyarrhythmias divided by occurrence of (A) gap‐related persistent conduction (gap‐RPC) and (B) carina‐related persistent conduction (carina‐RPC)