Novel real-time ECG imaging guidance for precise conduction system pacing

Background Left Bundle branch area pacing is currently the procedure of choice for various indications including atrioventricular block and considered to be physiologic modality of pacing compared to RV apex pacing especially in young adults. Objectives The purpose of this study was to analyse the feasibility and precision of real-time ECGI guidance during LBBAP lead placement. Methods This is single center prospective proof-of-concept study. 10 consecutive patients who underwent an LBBAP device implantation under real time ECGI guidance have been included in the study. Lead positioning was initially performed using Fluoroscopy and PSA only, then ECG and ECGI analysis were performed in the real time during the implantation at each lead position before and after fixation. ECG and ECGI parameters were measured. Activation maps have been created for each attempt prior lead fixation to ensure correct final position. Correlation analysys between 12 Lead ECG and ECGI values has been performed to analyse redundancy of ECGI. Results LBBAP implantation was successful in all patients. ECGI shown to be fast and visual way to assess intraventricular activation at every stage of CSP lead implantation. Lower septal sheath positions are associated with long TVACT and higher IVDS compared to higher septal sheath positions. All procedures were performed with only one screwing attempt. Screwing depth is mostly characterized by TVACT and LVACT reduction during screwing process. Previously described discordance between classic ECG parameters and ECGI analysis was confirmed and redundancy of certain parameters was confirmed. Correlation analysis confirmed the importance of ECGI measurement of right ventricle activation in general and total activation time and LVACT for patients with intrinsic QRS over 130 ms. Conclusions ECG imaging can bring a significant value into conduction system device implantation. ECGI allows direct visualization of every procedural step and its values confirm correct lead positioning and physiological ventricular activation. This might be very helpful in clinical practice by reducing nr of fixation attempts and proper activation assessment during the implantation, especially for patients with difficult cardiac and non-cardiac anatomy.