Conduction System Pacing: Basis and Scope

Long-term right ventricular pacing (RVP) is associated with more cardiovascular death, atrial fibrillation (AF), thromboembolic complications and heart failure(HF). RVP often results in prolonged QRS duration(QRSd) and ventricular desynchronization. The ventricular desynchronization as a result of RVP leads to an increased risk of heart failure hospitalization (HFH) and AF, and this effect is dependent on cumulative percent ventricular paced ( % VP). In the sub-study from the MOST trial, it was evident that % VP >40% was associated with a 2.6-fold increased risk of HFH compared with pacing < 40% of the time despite preserved atrioventricular synchrony. Moreover this adverse effect of RVP induced ventricular desynchrony was more pronounced in patients with left ventricular ejection fraction( LVEF) of 40% or less resulting in increased death or HFH.