Abstract 3355: Relationship Between Electrocardiographic Remodeling, Mechanical Remodeling and the Occurrence of Appropriate Therapy in Biventricular Implantable Cardioverter Defibrillator Patients

Abstract

Background: Cardiac Resynchronization Therapy (CRT) is associated with reverse left ventricular (LV) remodeling. However, the effect of CRT on electrical remodeling, reverse mechanical remodeling, occurrence of ventricular arrhythmias is not well established. Methods: D ata from 45 patients who underwent implantable cardioverter defibrillator(ICD)-CRT implantation was retrospectively analyzed. Patients had New York Heart Association (NYHA) functional class III or IV heart failure symptoms, left ventricular ejection fraction (LVEF) <35%, and QRS duration >130 ms or QRS ≤130ms with left intraventricular dyssynchrony. Significant LV reverse remodeling was defined by a decrease of left ventricular end diastolic diameter (LVEDd) by at least 10% after 1 year of follow up. Electrocardiographic indices of dispersion of repolarization (DR) (QTc, T peak-Tend (Tp-e) and their dispersion) were measured immediately and 1 year after implantation. The occurrence of appropriate ICD therapy was noted for each patient. Results: Patients with significant LV reverse remodeling (n=21) and without LV reverse remodeling (n=24) had similar baseline characteristics. After one year of follow up, patients with LV reverse remodeling exhibited a significant decrease in DR parameters (Tp-e, QT dispersion and Tp-e dispersion), and lower rate of appropriate ICD therapy (log rank p=0.002), compared to those without reverse remodeling who experienced an increase in DR parameters (QT dispersion and Tp-e dispersion), figure 1 . Conclusion: Mechanical LV reverse remodeling is associated with an electrical reverse remodelling and a lower rate of appropriate ICD therapy. Figure 1: Occurence of appropriate CD therapy according to LV reverse remodelling