Temperature Sensor-Mediated Intraoperative Tachycardia in a Leadless Pacemaker During Cardiac Surgery.

BACKGROUND: Leadless pacemaker use has grown with some now including temperature-based sensors rather than motion-based sensors. We present a case of unexpected rewarming-induced rapid pacing during cardiopulmonary bypass in a patient with the Aveir leadless pacemaker. CASE SUMMARY: We present a case of a patient with a leadless pacemaker undergoing cardiac surgery and suffering from rapid ventricular pacing when weaning from bypass treated by applying a magnet to stop rapid pacing with device interrogation conducted intraoperatively. The rate response feature was disabled with the patient weaned from bypass. DISCUSSION: Traditional pacemakers use rate response features whereas the Aveir leadless pacemaker uses a temperature-based response feature. For this reason, the device is susceptible to inappropriate pacing when patients undergo rewarming during cardiac surgery resulting in possible hemodynamic compromise. TAKE-HOME MESSAGE: Patients undergoing cardiac surgery with leadless pacemakers in place should have a careful preoperative evaluation with the rate response feature turned off before surgery if indicated.