Background: His bundle pacing (HBP) has evolved as the most physiological form of pacing but associated with limitations. Recently left bundle branch pacing (LBBP) is emerging as an effective alternative strategy for HBP. Objectives: Our study was designed to assess the feasibility, efficacy, electrophysiological parameters and mid-term outcomes of LBBP in Indian population Methods: All patients requiring permanent pacemaker implantation for symptomatic bradycardia and heart failure were prospectively enrolled. Echocardiography, QRS duration, pacing parameters, Left bundle(LB) potentials, paced QRS duration and peak left ventricular activation time (pLVAT) recorded. Results: LBBP was successful in 93 out of 99 patients (94% acute success). Mean age 62.6 ± 13 yrs. Male 59%, diabetes 69%, coronary artery disease 65%. Follow up duration 4.8 months (range1-12 months). Indication for pacing were atrioventricular (AV) block 43%, cardiac resynchronization therapy 40%, AV node ablation 4%. LB potential noted in 37 patients (40%). QRS duration reduced from 144.38 ±34.6ms at baseline to 110.8 ±12.4ms after LBBP (p value 0.0001). Pacing threshold was 0.59 ± 0.22V and sensed R wave 14.14 ± 7.19 mV and it remained stable during follow up. Lead depth in the septum was 9.62 mm. LV ejection fraction increased from 44.96 % to 53.3 % after LBBP (p value 0.0001). One died due to respiratory tract infection on follow up Conclusion: LBBP is a safe and effective strategy (94% acute success) of physiological pacing. The pacing parameters remained stable over a period of 12 months follow up. LBBP can effectively overcome the limitations of HBP
