This case report describes a rare complication of sheath rupture during Figure-of-Eight suturing following catheter ablation. A 44-year-old male undergoing electrophysiological testing experienced sudden sheath rupture upon removal, necessitating emergency surgical retrieval. The mechanism likely involved three factors: accidental needle puncture causing initial damage, excessive suture tension creating structural compromise, and shearing forces during removal precipitating complete rupture. Preventive strategies include maintaining appropriate needle placement away from the sheath, controlling suture tension, and retaining an intraluminal device during suturing for mechanical protection. This case emphasizes the importance of standardized procedural protocols and thorough operator training to enhance patient safety during vascular closure procedures.

An 84-year-old woman with type B WPW with Ebstein anomaly was admitted with heart failure. She had rapid wide QRS tachcardia due to accessory pathway conduction associated with atrial fibrillation (AF). Since transesophageal echocardiography before catheter ablation showed a left atrial thrombus, ablation was performed using a 3D mapping system under AF. After marking the functional tricuspid anulus with intracardiac echocardiography, three dimensional intracardiac electrogram visualization (ripple map) during AF enabled clear identification of location of the accessory pathway. After ablation, there was no complication of cerebral infarction and heart failure improved.

An 82-year-old woman received pacemaker implantation for sick sinus syndrome. Two days after the implantation, electrocardiography showed 2:1 atrial pacing failure, followed by bradycardia-dependent increase in the atrial pacing threshold during a pacemaker examination. However, transient 1:1 atrial pacing capture recovered by adenosine triphosphate (ATP) administration, which was performed to evaluate the bradycardia-dependent pacing failure mechanism. We considered this phenomenon to be caused by phase 4 depolarization and avoided replacing this atrial lead. Three weeks later, the atrial pacing threshold had improved. We report the potential role of phase 4 depolarization in bradycardia-dependent increase in pacing threshold by using ATP.