Impact of the arrhythmogenic potential of long lines of conduction slowing at the pulmonary vein area

Abstract

Background: Areas of conduction delay (CD) or conduction block (CB) are associated with higher recurrence rates after ablation therapy for atrial fibrillation (AF). Objective: Thus far, there are no reports on the quantification of the extensiveness of CD and CB at the pulmonary vein area (PVA) and their clinical relevance. Methods: Intraoperative high-density epicardial mapping of the PVA (interelectrode distance 2 mm) was performed during sinus rhythm in 268 patients (mean ± SD [minimum–maximum] 67 ± 11 [21–84] years) with and without preoperative AF. For each patient, extensiveness of CD (conduction velocity 17–29 cm/s) and CB (conduction velocity <17 cm/s) was assessed and related to the presence and type of AF. Results: CD and CB occurred in, respectively, 242 (90%) and 183 (68%) patients. Patients with AF showed a higher incidence of continuous conduction delay and block (CDCB) lines (AF: n = 37 [76%]; no AF: n = 132 [60%]; P =.046), a 2-fold number of lines per patient (CD: 7 [0–30] vs 4 [0–22], P