Conduction system pacing following septal myectomy: Insights into site of conduction block

Abstract

Introduction: Septal myectomy for obstructive hypertrophic cardiomyopathy (HCM) is associated with conduction block; however, the electrophysiological characteristics of conduction block have not been well characterized. The aim of study was to assess the feasibility and safety of His bundle pacing (HBP) and left bundle branch area pacing (LBBAP) in patients with septal myectomy-associated conduction block. Methods and Results: Patients with HCM and indications for pacing or cardiac resynchronization therapy after septal myectomy were included. Electrophysiological mapping was performed to identify the site of block. The success rates and pacing characteristics of HBP and LBBAP were also recorded. The echocardiographic data and complications were documented and tracked during follow-up. Ten patients with atrioventricular block (AVB) or left bundle branch block (LBBB) post-myectomy were included in the study. The site of block was infranodal in the nine patients with AVB. HBP failed due to the lack of distal His bundle capture (N = 7) or LBBB correction (N = 3). LBBAP was successful in nine patients and failed in one. QRS duration narrowed from 163.3 ± 16.6 ms after surgery to 123.6 ± 15.8 ms during LBBAP (p < .001). The mean depth of the leads was 13.3 ± 4.0 mm (range from 10 to 20 mm). At a mean follow-up

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

“…This finding confirms the pitfalls of permanent HBP described in previous studies and the importance of the electrophysiological properties of the conduction system in each patient. The correction of distal conduction abnormalities below the bundle of His is not achievable with this procedure, whether the goal is to capture the conduction system in narrow QRS patients [ 9 ] or to correct the existing bundle branch block [ 10 ].…”

Cardiovascular imaging in conduction system pacing: What does the clinician need?

“…25,26 Dilation of right atrium/ventricle, septal scar/fibrosis, and valvular regurgitation may affect the success rate of CSP implantation. [27][28][29] Secondly, the pre-procedure evaluation of septal anatomy should also be paid attention. LBBP leads are typically located in the basalmiddle or mid-middle region of the fluoroscopic boundary of the ventricle.…”

“…45 The fluoroscopy using septal angiography via sheath is commonly used to estimate the depth of lead in the septum during implantation procedure. 27,28,46,47 The case of lead perforation by fluoroscopy during the procedure was shown in Figure 1.…”

Conduction system pacing after septal myectomy: Obstruction of just‐His

“…These patients, however, represent a challenge due to a hypertrophied septum, myoarchitectural disarray, frequent ventricular scarring, and extensive surgical reduction adjacent to the proximal conduction system. 5 In this issue of the Journal of Cardiovascular Electrophysiology, 6 Zheng et al present the outcomes of 10 patients (58.4 ± 9.1 years, 6 male) from multiple institutions who underwent CSP for conduction system abnormalities after septal myectomy for HOCM. Mean LVEF was 56.5 ± 17.1% including three patients with an LVEF <50%.…”

“…In this issue of the Journal of Cardiovascular Electrophysiology , 6 Zheng et al present the outcomes of 10 patients (58.4 ± 9.1 years, 6 male) from multiple institutions who underwent CSP for conduction system abnormalities after septal myectomy for HOCM. Mean LVEF was 56.5 ± 17.1% including three patients with an LVEF <50%.…”