Search

Background: Precise mapping of the Purkinje fiber network is essential in catheter ablation of Purkinje‐related ventricular arrhythmias (PrVAs). We sought to evaluate the mapping ability of a multi‐spline duodecapolar catheter (PentaRay) for PrVAs. Methods: Mappings of Purkinje fibers by PentaRay catheters were compared with those by conventional mapping catheters in consecutive patients undergoing catheter ablation of PrVAs from 2015 to 2022. Results: Sixteen PrVAs (7 premature ventricular contractions or non‐reentrant fascicular tachycardias [PVCs/NRFTs] and 9 fascicular ventricular tachycardias [FVTs]) were retrospectively studied. In PVCs/NRFTs, earliest preceding Purkinje potentials (PPs) could be recorded by the PentaRay catheters but not by the mapping and ablation catheters in 5 cases. At the earliest PP sites, the precedence from the QRS onset was greater, and the amplitude of the preceding potentials was higher in the PentaRay catheter compared with those in the mapping and ablation catheter (−62.0 ± 42.8 vs. −29.4 ± 34.2 ms, P = 0.02; 0.45 ± 0.43 vs. 0.09 ± 0.08 mV, P = 0.02). In FVTs, late diastolic potentials (P1) were recorded by the PentaRay catheters but not by the mapping and ablation catheters or the linear duodecapolar catheter in 2 cases. The amplitude of P1 was higher in the PentaRay catheter compared with that in the linear duodecapolar catheter and the mapping and ablation catheters (0.72 ± 0.49 vs. 0.17 ± 0.18 vs. 0.27 ± 0.21 mV, P = 0.0006, P = 0.002). The localized critical PPs, defined as the earliest preceding potentials in PVCs/NRFTs and P1 in FVTs, could be recorded in all the patients by the PentaRay catheter. The mapping ability of critical PPs of PrVAs was better with the PentaRay catheter than with the conventional mapping catheters (16/16 vs. 9/16, P = 0.004 by McNemar exact test). Conclusions: The PentaRay catheter has clinical advantages in mapping of the Purkinje fiber network to reveal critical PPs as ablation targets of PrVAs. [ABSTRACT FROM AUTHOR]

Introduction: Ectopic beats originating from the pulmonary vein (PV) trigger atrial fibrillation (AF). The purpose of this study was to clarify the electrophysiological determinant of AF initiation from the PVs. Methods: Pacing studies were performed with a single extra stimulus mimicking an ectopic beat in the left superior PVs (LSPVs) in 62 patients undergoing AF ablation. Inducibility of AF, effective refractory period (ERP), and conduction properties within the PVs were analyzed. Results: A single extra stimulus in LSPV induced AF in 20 patients (32% of all patients) at the mean coupling interval (CI) of 172 ms. A CI‐dependent anisotropic conduction at the AF onset was visualized in a three‐dimensional mapping. Onset of AF was site‐specific with reproducibility in each individual. Mean ERP in LSPV in the AF‐inducible group was shorter than that in the AF‐noninducible group (182 ± 55 vs. 254 ± 51 ms, p <.0001). LSPV ERP dispersion was greater in the AF‐inducible group than in the AF‐noninducible group (45 ± 28 vs. 27 ± 19 ms, p <.01). Circumferential intra‐PV conduction time (IPVCT) exhibited decremental properties in response to shortening of CI and the prolongation of IPVCT in the AF‐inducible site was greater than that in the AF‐noninducible site (p <.05) in each individual. Conclusions: Location and CI of an ectopic excitation ultimately determine the initiation of AF from the PVs. ERP dispersion and circumferential conduction delay may lead to anisotropic conduction and reentry within the PVs that initiate AF. [ABSTRACT FROM AUTHOR]