Search

Abstract Background Focal Purkinje ventricular arrhythmias (VAs) might originate from the vicinity of the proximal portion of the cardiac conducting system. This study aimed to clarify the features associated with focal Purkinje VAs originating from the proximal conduction system. Methods A total of 18 patients with focal Purkinje VAs undergoing radiofrequency catheter ablation (RFCA) were retrospectively examined and divided into the proximal type or the non‐proximal type. The proximal type was defined as having the origin at the proximal half of the interventricular septum, or the proximal half and the septal side of the anterior wall. The 12‐lead electrocardiogram and electrophysiological findings were investigated. Results Seven patients met criteria for proximal type of focal Purkinje VA. Out of the 7, 4 patients with proximal VAs had multiple QRS morphologies of VAs clinically, whereas out of 11 patients with non‐proximal VAs, only 1 had multiple morphologies (p = .047). VA QRS duration was shorter in the proximal type than in the non‐proximal type (111.2 ± 19.8 ms vs. 135.7 ± 17.7 ms; p = .003). The absolute axis difference between sinus rhythm and VA was smaller in the proximal type (80.4 ± 46.1°vs. 138.8 ± 59.6°; p = .014). The absolute axis difference ≤134° was useful in distinguishing the two types. Recurrence of VA was recorded in 3 proximal type patients and 3 non‐proximal type patients. No procedure‐related conduction block was observed. Conclusion A VA of absolute axis difference ≤134°, and multiple QRS morphologies of clinical VAs indicate a proximal origin. Focal Purkinje VAs from proximal origins can be suppressed by RFCA without severe conduction disturbance.

Abstract Background The pulmonary veins (PVs) have unique electrophysiological properties triggering and maintaining atrial fibrillation (AF). Bigeminal PV electrical activity (PV bigeminy) during sinus rhythm has been reported; however, its mechanisms and clinical implication remain unclear. We hypothesized that PV bigeminy indicates arrhythmogenic activities and influences clinical outcome. Methods and Results We retrospectively analyzed electrophysiological studies in 465 patients with AF who underwent first session PV isolation (PVI). PV bigeminy was observed in 30 PVs of 23 patients (4.9% of patients). PV bigeminy was observed in left inferior PV (LIPV) in 15 patients, which was the most prevalent, followed by left superior in seven and right superior in seven and right inferior in one. In response to atrial extra stimulus, the second PV potentials (PV2) showed decremental conduction properties, suggesting reentrant mechanisms involved (n = 5). Interestingly, AF was initiated from the 23 PVs with bigeminy in 21 patients (76.7% of 30 PVs with bigeminy), spontaneously or in response to drugs, which was significantly more prevalent from the AF initiation rate from each PV in the control 442 patients (182 firings in 1290 PVs, 14.1%, P

Abstract Background Induction test of atrial fibrillation (AF) is one of endpoint measures in catheter ablation (CA). However, its predictive value in long‐term outcome remains controversial. Methods Ninety‐eight patients (61 years, 77 males) with persistent AF who underwent pulmonary vein antrum isolation‐based CA were retrospectively analyzed. We determined whether inducibility of AF/atrial tachyarrhythmias (AT) by atrial burst pacing at the end of CA and other characteristics were associated with the recurrence of AF/AT. Atrial burst pacing was performed with 30‐beat from the coronary sinus; increasing from 240 to 320 ppm. Inducibility was defined as AF/AT lasting ≥5 minutes following atrial burst pacing. Results AF/AT was induced in 50 patients (51%). During 1 year of follow‐up, 71 patients (72.4%) had no recurrence of AF/AT. A logistic regression analysis showed that female gender (OR 3.8; P = 0.02), multiple sessions (OR 3.5; P = 0.02), and early recurrence of AF/AT (OR 5.3; P = 0.004) were associated with clinical recurrence. AF/AT Inducibility was not associated with clinical recurrence (P = 0.65). A subanalysis in patients with enlarged LA (LA diameter ≥45 mm, n = 40) showed that AF/AT inducibility was associated with recurrence (OR 8.1; P = 0.04). The positive and negative predictive values of AF/AT inducibility for AF/AT recurrence were 41 and 89%, respectively. Negative predictive value was increased to 92.3% when the inducibility was defined as AF/AT of ≥30 seconds following atrial burst pacing. Conclusions AF/AT inducibility cannot predict long‐term clinical recurrence in patients with persistent AF. However, it may have a prognostic value especially in patients with enlarged LA.