[Physiological pacing and cardiac resynchronization therapy: state of the art]

Permanent cardiac pacing has progressively evolved toward increasingly physiological strategies aimed at preserving or restoring ventricular electromechanical synchrony. Cardiac resynchronization therapy using biventricular pacing remains the established standard of care for patients with heart failure, reduced left ventricular ejection fraction and electrical dyssynchrony, particularly in the presence of left bundle branch block. However, anatomical constraints, suboptimal clinical and echocardiographic response, and procedural complexity have promoted the development of conduction system pacing. His bundle pacing and, more recently, left bundle branch area pacing directly recruit the His-Purkinje system and may provide faster and more physiological ventricular activation. This narrative review summarizes current indications, technical aspects, the most relevant clinical evidence in bradyarrhythmias and heart failure, and the evolution of dedicated tools and leads. Available data support conduction system pacing over conventional right ventricular pacing in patients with a high expected pacing burden, with potential benefits in terms of ventricular function and heart failure events. By contrast, its role as an alternative to conventional biventricular resynchronization remains debated.