Persistent sinus node dysfunction after biatrial heart transplantation successfully managed with CT-guided leadless atrial pacing: a case report.

Background: Sinus node dysfunction (SND) is a well-recognized complication after orthotopic heart transplantation (OHT), particularly in recipients of biatrial anastomosis. In this setting, conventional transvenous pacing may be technically challenging due to complex post-surgical anatomy and increased infection risk. Case summary: A 36-year-old woman with restrictive cardiomyopathy underwent successful biatrial OHT. Eleven months later, she presented with persistent junctional rhythm and exertional fatigue. Electrophysiological study confirmed electrical dissociation between the donor and recipient atria with preserved atrioventricular conduction but absent sinus activity. Considering her immunosuppressed status and challenging anatomy, a leadless atrial pacemaker (Aveir AR, Abbott) was implanted under three-dimensional computed tomography (CT)-fluoroscopy fusion guidance. The device was positioned at the base of the donor right atrial appendage, achieving optimal electrical parameters. The procedure was completed without complications, and at follow-up, the patient showed complete symptom resolution and improved chronotropic response. Conclusion: This case demonstrates the feasibility and safety of CT-fluoroscopy-guided leadless atrial pacing in a post-transplant recipient with persistent SND, highlighting the value of advanced imaging for accurate spatial orientation and device deployment in complex post-surgical anatomy.