PO-04-086 IMPLANTATION OF A LEADLESS PACEMAKER FOR HYBRID DUAL CHAMBER PACING IN A PATIENT WITH A FAILING RIGHT VENTRICULAR LEAD AND HIGH SURGICAL RISK: A CASE REPORT

Abstract

Mechanical atrial sensing in Micra AV (Medtronic) leadless pacemakers facilitates atrioventricular (AV) synchrony in patients with AV block despite single chamber pacing. Little data is available on the efficacy of Micra AV atrial tracking in patients with concomitant sinus node dysfunction requiring atrial pacing. We present a case that demonstrates the efficacy and utility of Micra AV pacing in the context of transvenous atrial pacing. N/A A 49-year-old woman with complete heart block, sinus node dysfunction, right-sided dual-chamber pacemaker, and subsequent right atrial (RA) lead dysfunction treated with RA lead capping and new implantation, presented to our institution for pacemaker management. Device interrogation revealed rising RV lead impedances and pacing thresholds, for which lead extraction and re-implantation was recommended. Pre-operative imaging revealed partial flow obstruction in the right subclavian vein, an interrupted inferior vena cava, and a persistent left superior vena cava (SVC) with no right SVC connection. As urgent intra-operative cardiopulmonary bypass in the event of vascular rupture would prove difficult, the patient was deemed not a candidate for lead extraction. In an effort to prevent SVC syndrome, the decision was made to implant a Micra AV leadless pacemaker and program the old RV lead to off. The patient’s anatomy precluded a conventional femoral venous approach to Micra implantation, so implantation was achieved via the right internal jugular vein. The procedure was successful without intraprocedural complication. To allow for atrial pacing and to promote AV synchrony, the dual chamber pacemaker was programmed to AAIR 70/100 bpm with the leadless pacemaker programmed to VDD 50/105 bpm. Quarterly device interrogations in the 12 months following Micra implantation demonstrated 77-92% RA pacing and 99% RV pacing with atrial tracking from the Micra device at 76-83% with optimized atrial sensing. This case exemplifies the clinical scenario in which hybrid dual chamber pacing may be indicated. The case also highlights the atrial tracking capability of the Micra AV leadless pacemaker in the setting of an AAIR transvenous pacemaker, ultimately demonstrating the feasibility and potential application of hybrid dual chamber pacing in patients in need of RV lead revision but with prohibitive surgical risk or limited venous access.