Physiological Pacing in Congenitally Corrected Transposition of the Great Arteries with Atrioventricular Block

Congenitally corrected transposition of the great arteries (CCTGA) is a rare congenital heart disease characterized by atrioventricular, ventriculoarterial, and conduction system discordance, commonly accompanied by atrioventricular block (AVB). Pacing in patients with CCTGA and AVB (both pediatric and adult) poses challenges in strategy selection, procedural complexity, and clinical decision-making due to limited evidence. Conventional morphological left ventricular pacing is widely adopted but may induce ventricular dyssynchrony, heart failure, and tricuspid valve dysfunction. While cardiac resynchronization therapy serves as an upgrade for pacing-induced cardiomyopathy and heart failure, its application may be limited by coronary sinus anatomical variations and uncertain clinical outcomes. His bundle pacing is rarely reported due to the variation of the His bundle and high pacing threshold. The superficial, wide, multi-branched left bundle branch favors left bundle branch pacing, though delayed systemic right ventricle (sRV) activation may cause ventricular dyssynchrony and impair sRV function. Right bundle branch pacing offers a novel alternative for pacing therapy. Conduction system pacing-optimized cardiac resynchronization therapy is preferred in those with evidence of intrinsic ventricular conduction dysfunction. This narrative review synthesizes current evidence on pacing strategies for CCTGA with AVB, integrating anatomical and pathophysiological insights to evaluate physiological pacing strategies, while highlighting critical knowledge gaps to guide future research.