Quantitative distance and electrocardiographic parameters for lead-implanted site selection to enhance the success
Wenzhao Lu1, Jinxuan Lin1, Keping Chen2
1State Key Laboratory of Cardiovascular Disease, Arrhythmia Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 167, Beilishi Road, Xicheng District, Beijing, 100037, China.
Background:
Left bundle branch pacing (LBBP) is a novel near-physiological pacing method that still lacks quantitative criteria to guide the selection of lead-implanted sites to enhance the success likelihood of lead deployments. This study aimed to quantitatively analyze the relationships of LBBP success likelihood to the distribution of lead-implanted sites and the lead-localization-pacing electrocardiographic (ECG) features.
Methods:
All the lead-implanted sites in patients with finally successful LBBP were enrolled for analysis, including successful and failed sites. A novel coordinate system was invented to describe the sites' distribution as longitudinal distance (longit-dist) and lateral distance (lat-dist). Corrected distance parameters were generated to eliminate the cardiac dimension variations. The lead-localization-pacing ECG parameters were also collected, such as paced QRS duration (locat-QRSd), left ventricular activation time (locat-LVAT), LVAT/QRSd ratio (locat-LVAT/QRSd), and QRS directions.
Results:
A total of 94 patients with 105 successful sites and 93 failed sites were enrolled. Longit-dist and corrected longit-dist of successful sites were significantly longer, while locat-QRSd and locat-LVAT were shorter and locat-LVAT/QRSd was lower than failed sites. There was a positive dose-response relationship between LBBP success likelihood and corrected longit-dist with a cut-off of 26.95 mm, whereas there were negative dose-response relationships of LBBP success likelihood to locat-QRSd, locat-LVAT, and locat-LVAT/QRSd with the cut-offs of 142 ms, 92 ms, and 64.7%, respectively. Downward QRS direction in II/III ECG leads was also associated with successful LBBP.
Conclusion:
Longit-dist, locat-QRSd, locat-LVAT, and locat-LVAT/QRSd were quantitative parameters to guide the selection of lead-implanted sites during LBBP implantation. Quantitative distance and electrocardiographic parameters for lead-implanted site selection to enhance the success likelihood of left bundle branch pacing. LBBP, left bundle branch pacing; Longit-dist, longitudinal distance; CL-apex-dist, distance from contraction line to apex; LBBB, left bundle branch block; IVCD, intraventricular conduction delay; Locat-QRSd, lead-localization-pacing QRS duration; Locat-LVAT, lead-localization-pacing left ventricular activation time; Locat-LVAT/QRSd, lead-localization-pacing LVAT/QRSd ratio.
