A novel 9-partition method using fluoroscopic images for guiding left bundle branch pacing

Background: Left bundle branch (LBB) pacing is a novel pacing modality, but there is no standard fluoroscopic methodology.

Objectives: 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 right anterior oblique 30° projection was determined. The region between the apex and the ventricular contraction ring was divided into 9 partitions. All patients underwent postoperative computed tomography to confirm components of the ventricular contraction ring and to measure the distance from the lead tip to the junction of the noncoronary aortic cusp and right coronary cusp.

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 94.3% (33/35) of LBB pacing leads were in the junctional area of second and fifth partitions. The computed tomography image confirmed that the ventricular contraction ring was composed of cardiac valves. The distance from the lead tip to the junction of the noncoronary cusp and right coronary cusp of LBB and HB pacing leads was 3.8 ± 0.6 and 1.9 ± 0.2 cm, respectively. Under the guidance of the 9-partition method, the success rate of LBB pacing in 30 prospective patients increased from 58.3% (35/60) to 83.3% (25/30) (P = .03). The fluoroscopy time and the number of screwing sites also significantly decreased.

Conclusion: The distributions of HB and LBB pacing leads exhibited unique imaging characteristics. A new 9-partition method is useful to guide successful LBB pacing.