The evolution and future of conduction system pacing.

Cardiac pacing has undergone a fundamental paradigm shift from conventional right ventricular apical pacing towards physiological activation of the native conduction system of the heart. Decades of evidence have established that chronic right ventricular pacing induces ventricular dyssynchrony, contributing to pacing-induced cardiomyopathy and adverse clinical outcomes. Conduction system pacing, which engages the intrinsic His-Purkinje network of the heart, has emerged as a transformative approach that preserves or restores the natural ventricular activation sequence. His bundle pacing, the earliest form of conduction system pacing, provided proof of concept but is limited by technical challenges and high capture thresholds. Left bundle branch area pacing has since become the dominant modality, offering greater procedural success, lead stability and broader applicability: from management of bradycardia and prevention of pacing-induced cardiomyopathy to cardiac resynchronization therapy in heart failure. Bachmann bundle area pacing is an emerging atrial counterpart: by capturing a preferential interatrial conduction pathway, this approach reduces interatrial conduction delay and produces a more physiological atrial activation sequence than conventional right atrial appendage pacing. Bachmann bundle area pacing might, therefore, help to prevent atrial fibrillation. In this Review, we bring these ventricular and atrial strategies together under the unifying principle of physiological pacing, describe their mechanistic basis and technical evolution, appraise the latest evidence from randomized trials and address the practical questions that arise in clinical application, indicating where more evidence is required.