Association between Characteristics of Left Ventricular Pacing Lead and Reverse Remodeling in Response to Cardiac Resynchronization Therapy

Abstract

Backgrounds: It has been shown that the position of left ventricular (LV) pacing lead and viability of the LV wall may affect on the response to cardiac resynchronization therapy (CRT). However, little is known about the association between characteristics of LV pacing lead and LV reverse remodeling in chronic heart failure (CHF) patients with CRT implantation. Methods: The study subjects consisted of 32 CHF patients (23 males, mean age, 64±11 years) with CRT-defibrillator (CRT-D) implantation. We measured LV end-systolic volume (LVESV) by echocardiography before and 6 months after CRT-D implantation and defined the CRT responder as >15% reduction of LVESV at 6 months. The patients were divided into 2 groups based on CRT responder (group-A, n=20) or not (group-B, n=12). We compared the LV R-wave amplitude at CRT-D implantation and the change of LV pacing threshold 6 months after CRT-D implantation between 2 groups. Results: LV R-wave amplitude did not differ between 2 groups (A, 15.1±8.1 mV vs. B, 14.5±8.6 mV). In addition, the change in LV pacing threshold was similar between two groups (improving: 5% vs. 8%; worsening: 25% vs. 25%). Conclusions: These results suggest that electrophysiological properties of regional left ventricle at CRT implantation site do not predict the LV reverse remodeling in response to CRT in CHF patients.