Coronary sinus cannulation as real time anatomical landmark to facilitate left bundle branch area pacing

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND/INTRODUCTION: Left bundle branch area pacing (LBBAP) is an established form of conduction system pacing. Innovative fluoroscopic imaging technique with use of radio-opaque contrast in the right ventricle or using pre-mapped His potential has been advocated as an acquired road map to assist in implantation of LBBAP(1) lead. PURPOSE: We aim to explore a different technique by cannulating the coronary sinus (CS) with a sheath and wire to provide real-time anatomical guidance of location of the base of the heart to facilitate more effective LBBAP in a consistent fashion. METHODS: Prior to LBBAP, the body of the CS is cannulated using an AL2 diagnostic angiographic catheter and a 0.035-inch glidewire. The wire is fixated externally, and fluoroscopic image is acquired before proceeding with deployment of the pacing lead onto an optimal ventricular septal position via standard right (RAO 30) and left anterior oblique (LAO 30) views. From August 2021 to October 2022, we enrolled 12 consecutive patients requiring pacemaker for standard indications and explored the CS cannulation method in delivering LBBAP with either steerable catheters or fixed shape sheaths. Thereafter, we analysed and described the success rates, immediate electrical and device parameters, procedural durations, and clinical events. RESULTS: 12 patients were studied. The mean age was 75 ± 13.07 years and 6 (50%) patients were male. 1 (8.3%) was for sinus nodal dysfunction, 10 (83.3%) for atrioventricular block and 1 (8.3%) for atrial fibrillation (AF) control with atrioventricular node ablation. Mean left ventricular ejection fraction was 54.17 ± 8.21 % and baseline QRS was 108.08 ± 23.20ms. LBBAP was successful in all 12 patients based on published criteria with a mean paced QRS duration of 115.25 ± 9.28 ms. The mean total procedure duration was 130.75 +/- 29.84 minutes and mean fluoroscopic duration was 23.17 ± 9.11 minutes. After 1st week post implant, the pacing threshold, sensing, and impedances were stable and acceptable in all the patients. There were no acute complications (e.g. pneumothorax, lead complications, lead dislodgements / perforations) during the periprocedural period. CONCLUSION(S): The CS cannulation method is a feasible, safe, and effective method to to provide real-time anatomical visualisation of the base of the heart. This facilitates the achievement for optimal LBBAP and can be adopted especially in difficult cardiac anatomies or rotated cardiac silhouettes identified on fluoroscopy. [Figure: see text] [Figure: see text]