Innovative approach to conduction system pacing: Real-time ECG imaging guidance for precise left bundle branch area...

Left bundle branch area pacing is currently the procedure of choice for various indications including atrioventricular block and is considered a physiological modality of pacing compared with right ventricular apex pacing especially in young adults.

This study aimed to increase the precision of left bundle branch area pacing (LBBAP) lead placement by developing a novel implantation technique using electrocardiographic imaging (ECGI).

This is a single-center prospective 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 a pacemaker analyzer only; then electrocardiographic (ECG) and ECGI analyses were performed in real time during the implantation at each lead position before and after fixation. ECG and ECGI parameters were measured as previously described. A directional activation map has been created for each attempt before lead fixation to ensure the final position. Correlation analysis between 12-lead ECG and ECGI values has been performed to analyze redundancy.

LBBAP implantation was successful in all patients. ECGI has been shown to be a fast and visual way to assess interventricular activation at every stage of conduction system pacing lead implantation. Inferoposterior sheath positions are associated with long total ventricular activation time using ECGI and higher interventricular dyssynchrony than anterosuperior septal sheath positions. All procedures were performed with only 1 screwing attempt. Screwing depth is mostly characterized by total ventricular activation time and left ventricular activation time using ECGI reduction during the 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 ventricular activation in general and total activation time and left ventricular activation time for patients with an intrinsic QRS duration of >130 ms.

ECGI can bring significant value to 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 the number of fixation attempts and proper activation assessment during the implantation, especially for patients with difficult cardiac and noncardiac anatomy.