Risk of Pacing-Induced Cardiomyopathy in Patients with High-Degree Atrioventricular Block—Impact of Right Ventricular Lead Position Confirmed by Computed Tomography

Abstract

Prospective studies applying fluoroscopy for assessment of right ventricular (RV) lead position have failed to show clear benefits from RV septal pacing. We investigated the impact of different RV lead positions verified by computed tomography (CT) on the risk of pacing-induced cardiomyopathy (PICM). We retrospectively included 153 patients who underwent routine fluoroscopy-guided pacemaker implantation between March 2012 and May 2020. All patients had normal pre-implant left ventricular ejection fraction (LVEF). Patients attended a follow-up visit including contrast-enhanced cardiac CT and transthoracic echocardiography. Patients were classified as septal or non-septal based on CT analysis. The primary endpoint was PICM (LVEF < 50% with ≥10% decrease after implantation). Based on CT, 48 (31.4%) leads were septal and 105 (68.6%) were non-septal. Over a median follow-up of 3.1 years, 16 patients (33.3%) in the septal group developed PICM compared to 31 (29.5%) in the non-septal group (p = 0.6). Overall, 13.1% deteriorated to LVEF ≤ 40%, 5.9% were upgraded to cardiac resynchronization therapy device, and 14.4% developed new-onset atrial fibrillation, with no significant differences between the groups. This study demonstrated a high risk of PICM despite normal pre-implant left ventricular systolic function with no significant difference between CT-verified RV septal or non-septal lead position.

The role of contractile dyssynchrony in pacing-induced cardiomyopathy: detailed assessment using index of contractile asymmetry

“…In a previous study, using the same RV lead categories, we found no significant association between RV lead position and risk of PICM [ 2 ]. Meanwhile, the present study shows an association between both RV lead position and the degree of LV dyssynchrony and an association between the degree of LV dyssynchrony and PICM.…”

“…Driven by the dyssynchronous activation of the myocardium, right ventricular (RV) pacing may have detrimental effects on left ventricular (LV) function resulting in pacing-induced cardiomyopathy (PICM) [ 1 , 2 ]. It has long been hypothesized that RV septal pacing is superior to non-septal pacing due to the proximity to the specialized conduction system [ 3 ].…”

Paced QRS morphology mimicking complete left bundle branch block induced by right ventricular pacing is associated with pacing‐induced cardiomyopathy

“…Furthermore, some studies have reported that lead position did not significantly affect LV systolic function or PICM development. [23][24][25][26] Therefore, we acknowledge that lead position may be a confounding factor; however, we believe that this study underscores the importance of CLBBB-like paced QRS in PICM development.…”