Left Bundle Branch Area Pacing in Heart Failure: A Physiological Alternative to Conventional Biventricular Cardiac Resynchronization Therapy and a Step Towards Personalized Device Therapy

Heart failure remains a major cause of morbidity and mortality despite advances in guideline-directed medical therapy and device-based treatment. Cardiac resynchronization therapy delivered by conventional biventricular pacing constitutes an established therapeutic strategy for selected patients with heart failure with reduced ejection fraction and electrical desynchrony. Left bundle branch area pacing has emerged as a physiological pacing strategy that directly engages the conduction system, providing more effective electrical and mechanical resynchronization. Current evidence from observational studies, randomized pilot trials, and recent multicentre data suggest that left bundle branch pacing may achieve greater QRS narrowing, more favourable pacing thresholds, improved left ventricular ejection fraction, and reduced heart failure hospitalizations compared with conventional biventricular pacing in selected patients. This review summarizes the rationale, implantation criteria, patient selection, and current clinical evidence supporting left bundle branch pacing as an alternative pacing modality in heart failure patients. Despite encouraging available data, larger randomized trials with longer follow-up and broader patient populations are required to clarify long-term safety and to determine whether left bundle branch pacing should be adopted as a routine alternative to conventional cardiac resynchronization therapy. From a personalized medicine perspective, the choice between conduction system pacing and conventional biventricular pacing should be guided by individual patient characteristics, including conduction phenotype, QRS morphology and duration, myocardial scar burden, heart failure aetiology, coronary venous anatomy, and the chance of achieving confirmed conduction-system capture. This review therefore renders left bundle branch pacing within an individualized, phenotype-guided resynchronization strategy rather than as a universal replacement for biventricular pacing.