Abstract
BACKGROUND: Dual-chamber leadless pacing is an emerging technology that demands careful anatomical assessment, particularly for atrial capsule positioning. CASE SUMMARY: A 66-year-old woman with prior mediastinal radiotherapy and bilateral breast cancer presented with complete atrioventricular (AV) block. A ventricular AVEIR leadless pacemaker was initially implanted with stable electrical parameters. Because of exertional dyspnea suggestive of AV dyssynchrony, an atrial AVEIR right atrial capsule was subsequently added. Intraoperative right atrial angiography revealed a prominent Thebesian vein, prompting capsule implantation in a posterolateral position. This approach enabled effective AV synchrony, resulting in a rapid symptomatic improvement. DISCUSSION: This case report underscores the importance of intraoperative imaging to identify anatomical variants that may affect leadless pacemaker implantation. It also supports the clinical relevance of restoring AV synchrony in selected patients initially treated with single-chamber pacing. TAKE-HOME MESSAGES: Intraoperative right atrial imaging enhances leadless device placement. AV synchrony restoration may offer significant symptomatic benefit.