Cardiac transplant-associated complete AV block treated with a leadless pacemaker: a case report.

Background: Complete atrioventricular (AV) block is a rare complication immediately following orthotopic heart transplantation (OHT), typically attributed to ischaemic injury or surgical trauma. In immunosuppressed patients, pacemaker selection requires careful consideration due to heightened infection risk. Case summary: We present a 48-year-old woman with hypertrophic cardiomyopathy who developed persistent complete AV block with no ventricular escape following OHT. The early postoperative period was complicated by right ventricular failure and severe systemic infections. After stabilization, on Day 32 post-transplant, a Micra AV2 leadless pacemaker was implanted due to high infectious risk and presence of moderate-to-severe tricuspid regurgitation. The procedure was successful, with no complications and adequate AV synchrony after optimization. The patient remained clinically stable, with no pacemaker-related complications or rejection on biopsy, and was discharged on Day 45. Discussion: This is the first reported case of Micra AV2 implantation in a transplant recipient. Leadless AV-synchronous pacemakers may be an ideal option in select patients early post-transplant, especially those at high risk for infection and with tricuspid valve dysfunction.