The Impact of Cardiac Chamber Volumes on Permanent His Bundle Pacing Procedural Outcomes—A Single Center Experience

Abstract

His bundle pacing (HBP) has several pitfalls, such as the inability to identify the His bundle and lack of capture at acceptable thresholds. The majority of data regarding HBP were obtained using a dedicated non-deflectable delivery system. This study aimed to evaluate the impact of cardiac chamber dimensions on permanent HBP procedural outcomes when using this type of fixed-curve catheter. Seventy-two patients subjected to HBP from the 1st of January to the 31st of December 2021 at our institution were retrospectively reviewed. The baseline clinical characteristics and echocardiographic measurements of all the cardiac chambers were recorded, as well as procedural outcomes (HB electrogram identification and overall procedural success). During the procedure, the HB electrogram was recorded in 59 patients (81.9%) and successful permanent HBP was achieved in 33 patients, representing 45.8% of all the studied patients. Left atrial (LA) and right atrial (RA) volumes were significantly higher in patients without HB electrogram identification. Only LA and RA volumes were statistically associated with HB electrogram localization, while there was no significant association between the echocardiographic parameters and procedural success. LA volumes above 93 mL and RA volumes above 60 mL had an 8.81 times higher chance of failure to localize the HB electrogram compared with patients with lower volumes (p < 0.001). When considering non-deflectable delivery catheters for HBP, careful preprocedural echocardiographic analysis of the atrial volumes could help in the proper selection of implanting tools, thus optimizing the procedural outcomes and costs.

Feasibility of Conduction System Pacing in Patients with Baseline Bundle Branch Block—A Single-Center Mid-Term Follow-Up Study

“…We have shown in previous studies that both left and right atrial enlargements were significantly associated with failure to identify the HB electrogram when using a nondeflectable catheter and that baseline QRS duration was a prognostic factor for HBP procedural failure [19]. In the present study, although we used non-deflectable and deflectable catheters, atrial volumes, right ventricular diameter, and baseline QRS width were significantly associated with HBP procedural failure.…”

Optimal Cardiac Resynchronization Therapy with Conduction System Pacing Guided by Electro-Anatomical Mapping: A Case Report

“…First, most patients with heart failure and LBBB have a modified anatomy, enlarged atria and/or ventricles, and valvular regurgitations, resulting in an anteriorly and potentially distal displacement of the HB position. We have shown in a previous study that enlarged atria are significantly associated with failure to identify the HB electrogram [5]. On the other hand, since existing data states that in up to 60% of the LBBB patients, the site of the block is within the HB itself or the proximal LBB, we believe it is worthwhile to search initially for the HB [6].…”