A novel nine-partition method using fluoroscopic images for guiding left bundle branch pacing.

Abstract Background Left bundle branch (LBB) pacing is a novel pacing modality but there is no standard fluoroscopic methodology. Objective This study aimed to analyze the characteristics of His bundle (HB) and LBB pacing lead locations and establish a method to guide LBB pacing using fluoroscopic images. Methods Seventy patients who underwent HB or LBB pacing were enrolled. The fluoroscopic image was recorded and ventricular contraction ring in the RAO 30° projection was determined. The region between the apex and ventricular contraction ring was divided into nine partitions. All patients underwent postoperative CT scan to confirm components of ventricular contraction ring and to measure the distance from lead tip to junction of non-coronary and right coronary cusp (Tip-NCC). Results HB and LBB pacing leads were successfully implanted in 11 and 35 patients, respectively. All HB pacing leads were distributed in the second partition, and 94.2% of LBB pacing leads were in the junctional area of second and fifth partitions. CT image confirmed that ventricular contraction ring was composed of cardiac valves. The Tip-NCC distance of LBB and HB pacing leads were 3.8 ± 0.6 cm and 1.9 ± 0.2 cm. Under the guidance of the nine-partition method, the success rate of LBB pacing in 30 prospective patients increased from 58.3% to 83.3% (p = 0.03). The fluoroscopic time and number of screwing sites also significantly decreased. Conclusion The distributions of HB and LBB pacing leads exhibited unique imaging characteristics. A new nine-partition method is useful to guide successful LBB pacing.