Abstract
BACKGROUND: Recent studies have confirmed the feasibility and safety of cavotricuspid isthmus (CTI) ablation using either a pentaspline or a focal monopolar pulsed-field ablation catheter. However, no documented cases have reported irreversible heart block as a potential complication. CASE SUMMARY: A 62-year-old woman with persistent atrial fibrillation underwent CTI ablation using a pentaspline pulsed-field catheter after pulmonary vein isolation. Immediately postablation, third-degree atrioventricular block occurred, transiently recovering to 2:1 block before reverting to complete heart block. A permanent pacemaker was subsequently implanted given irreversible conduction impairment. DISCUSSION: We report to our knowledge the first case of irreversible heart block after CTI ablation using a pentaspline pulsed-field ablation catheter, necessitating permanent pacemaker implantation after 13 hours of observation. This case underscores the need for caution when employing this technology for CTI ablation. TAKE-HOME MESSAGE: Irreversible heart block is a novel, albeit rare, complication of CTI ablation with a pentaspline pulsed-field catheter.