First-in-Human Permanent Totally Leadless Left Ventricular Septal Endocardial Pacing With Atrioventricular Synchrony.

BACKGROUND: Leadless cardiac resynchronization combining WiSE system ultrasound-mediated left ventricular pacing with leadless right ventricular pacing has been reported. However, atrioventricular-sequential left ventricular pacing triggered by atrial leadless pacing impulse without right ventricular pacing has not been reported. FIRST-IN-HUMAN/EARLY REPORTS SUMMARY: An 86-year-old man with complete heart block and cardiomyopathy received a dual-chamber leadless pacemaker (AVEIR DR) with WiSE left ventricular endocardial electrode on the septal wall. A novel "sync-to-pace" delay configuration enabled the atrial pacing impulse to trigger left ventricular stimulation, achieving a QRS duration of 142 ms. DISCUSSION: This case demonstrates proof of concept for a fully leadless atrioventricular-synchronized system capable of delivering left ventricular septal endocardial pacing without right ventricular pacing dependency, offering a physiological pacing strategy for selected patients. NOVELTY: First-in-human demonstration of an ultrasound-mediated left ventricular endocardial electrode triggered by an atrial leadless pacing impulse to deliver atrioventricular-sequential left ventricular septal stimulation without right ventricular pacing. TAKE-HOME MESSAGE: This novel totally leadless architecture is a proof of concept for a more physiological pacing option for pacing-dependent patients while avoiding transvenous lead-related complications.