Conventional right ventricular pacing (RVP) has been associated with ventricular dyssynchrony and an increased risk of pacing-induced cardiomyopathy, which may lead to worse clinical outcomes. These adverse effects are more pronounced in patients with pre-existing left ventricular dysfunction. To overcome these limitations, left bundle branch area pacing (LBBAP), which directly engages the cardiac conduction system to preserve physiological ventricular activation, has been increasingly adopted in clinical practice.
However, in patients with atrioventricular block and preserved left ventricular ejection fraction (LVEF ≥50%), evidence demonstrating the long-term clinical superiority of LBBAP over conventional RVP remains limited. As a result, both pacing strategies continue to be used in current practice. This multicenter randomized trial aims to compare the efficacy, safety, and lead stability of LBBAP using a stylet-driven extendable screw-in lead versus conventional RVP in patients with atrioventricular block and preserved ejection fraction.
Third-degree AV block
First- or second-degree AV block with an expected ventricular pacing burden ≥40%
Atrial fibrillation with slow ventricular response with an expected ventricular pacing burden ≥40%
Prior implantation of a cardiac pacemaker or implantable cardioverter-defibrillator
Left ventricular ejection fraction ≤50%
Indication for cardiac resynchronization therapy
Life expectancy ≤1 year (e.g., patients not eligible for heart transplantation due to end-stage heart failure, patients with DNR orders, those receiving hospice care after refusal of life-sustaining treatment, or patients with terminal cancer not eligible for chemotherapy or radiotherapy)