Left bundle branch pacing is the best approach to physiological pacing

The last decade has seen the resurgence of conduction system pacing (CSP) for patients with symptomatic bradycardia and heart failure. His-bundle pacing (HBP) is now an accepted alternative to more traditional ventricular pacing sites (right ventricular [RV] apex/outflow tract, coronary sinus). Although HBP is theoretically the ideal physiological pacing site, it has some inherent limitations. The implant technique requires greater expertise in targeting a small zone and can be challenging in patients with dilated hearts, resulting in long procedural and fluoroscopic times. The reported success rate for HBP varies from 56% to 95%, depending on the degree of conduction system disease present and the experience of the center. Successful HBP lead implantation is fraught with troubleshooting issues during follow-up. HBP leads typically have a low R-wave amplitude that may result in oversensing of atrial or His signals and undersensing of ventricular signals. High HBP capture thresholds at implant and/or during late follow-up may result in premature battery depletion and repeated generator replacements and the associated risks. The unpredictable, delayed rise in HBP capture thresholds are a major concern, resulting in higher lead revision rates. A subset of patients may also lose His capture during followup, resulting in RV septal pacing. No robust data regarding the long-term performance of HBP leads are available. In the largest observational, 2center study, 844 patients who received HBP leads had a mean pacing capture threshold of 1.6 V at implant and 2 V at median follow-up of 3 years. HBP was free of any complications in 91% of patients. However, a careful appraisal of the data highlights the concerns noted in about 35%–40% of the patients. Pacing thresholds were 2.5 V at 1 ms in 28% of patients at median follow-up. Follow-up electrocardiography