Left bundle branch pacing.

Chronic right ventricular (RV) pacing has been associated with significant electrical and mechanical dyssynchrony leading to increased risk for recurrent heart failure hospitalizations and atrial arrhythmias. His bundle pacing (HBP) is an effective alternative to RV pacing as it is physiological and provides synchronized contraction of both ventricles. But there are limitations to HBP, which include lead stability, rise in threshold, early battery depletion and longer learning curve. Huang et al. recently reported a novel technique to directly capture the left bundle branch (LBB) by deep septal pacing. Subsequently, many studies have demonstrated the feasibility, safety and efficacy of left bundle branch pacing (LBBP). This has the potential to overcome the limitations of HBP and provide a safe technique to capture the conduction system in patients with distal His bundle and proximal bundle branch disease. The criteria for LBB capture and the methodology to perform LBBP are discussed in detail in this review. The Medtronic SelectSecure®3830 pacing lead is used along with a fixed-curve C315His® or a deflectable C304His® sheath. LBBP provides safe and low threshold compared to HBP. Left bundle potential should be demonstrable in all patients except in those with infrahisian complete heart block (CHB) and complete left bundle branch block (LBBB), wherein antegrade activation of the left bundle will not occur. LBBP has the potential to be an effective alternative to biventricular pacing or HBP in patients with left ventricular dysfunction, LBBB and recurrent heart failure. Long-term safety and clinical outcomes compared to traditional pacing need to be carefully studied in randomized clinical trials.