Atrioventricular synchronous pacing using leadless pacemaker in a heart transplant patient.

We report the first leadless pacemaker (L-PM) providing atrioventricular synchronous pacing implanted into a heart transplant patient receiving chronic immunosuppressive therapy. The patient presented with syncope corresponding to sinus rhythm with high-grade atrioventricular block. Previously, L-PMs provided only single-chamber ventricular sensing and pacing. A Micra AV lL-PM provides atrioventricular synchronous pacing by tracking mechanical atrial contraction. L-PMs, which now support broader indications, should be considered in patients at greater risk of infection.