Introduction
Left bundle branch pacing (LBBP) is a new and developing method of pacing that uses the patient’s native conduction system, with early results showing improved sensing and lower capture thresholds compared to His bundle pacing (1-4). Observational data suggest possible benefits for some patients compared to standard right ventricular (RV) pacing (5), and it is also an option for patients with heart failure and left bundle branch block who need cardiac resynchronization therapy (6, 7). LBBP involves inserting a pacemaker lead from the right ventricle, penetrating the interventricular septum to reach the area of the left bundle branch or one of its fascicles on the left side of the septum (8). A potential complication of LBBP is damage to a septal perforating branch of the left anterior descending coronary artery. A recent report described a transient ST-elevation myocardial infarction via vasospasm of this artery (9). Therefore, determining the optimal lead implantation site is required to ensure the safety and efficacy of LBBP.
Since the lead is inserted distal to the His bundle, and mapping of this can be used to provide a fluoroscopic landmark, knowing the range of distances between the His bundle and the first septal perforator artery would allow operators to choose the site of lead placement more safely and confidently. However, there are few published data regarding this. We reviewed coronary computed tomography angiography (CCTA) studies previously performed at our institution to evaluate this anatomy and define the range of distances between the His bundle and first septal perforator artery so as to guide operators on safe lead placement sites for LBBP.