Whole-heart electro-mechanical optimization: an integrative systems approach to modern cardiac pacing

Modern-day cardiac pacing is no longer limited to the treatment of bradycardia but can be tailored to optimize cardiac hemodynamics through coordinated modulation of heart rate, atrioventricular (AV) coupling, and atrial and ventricular activation patterns as an integrated system. While traditional approaches have addressed these components in isolation, this review summarizes the mechanisms and clinical evidence of a 'whole-heart electro-mechanical optimization' approach for the treatment of bradycardia.

Accelerated atrial pacing can lower left-sided filling pressures and improve symptoms in patients with heart failure with preserved ejection fraction and diastolic dysfunction. Bachmann bundle-area pacing restores physiological atrial activation, which not only improves diastolic filling and reduces atrial arrhythmia burden but also redefines the effective AV delay. AV-sequential pacing enables optimization of AV-coupling to enhance left ventricular filling by restoring appropriate timing between early ventricular filling and atrial contraction, and by reducing diastolic mitral regurgitation. Importantly, conduction system pacing, typically left bundle branch area pacing, preserves near-normal ventricular activation enabling the full hemodynamic benefits of the preceding interventions without pacing-induced dyssynchrony.

Together, these complementary and interdependent pacing strategies form an integrated 'whole-heart electro-mechanical optimization' approach aimed at integrative optimization of whole-heart pump function in selected patients.