Abstract 15244: Fragmented Wide QRS on a 12-Lead Electrocardiogram Increases the Risk of Ventricular Arrhythmias in Patients with Severe Systolic Dysfunction
Background: The current guidelines support Implantable Cardioverter Defibrillator (ICD) implantation in patients with a left ventricular ejection fraction (LVEF) below 35%, yet there are no clear discriminating parameters to assess which patients will gain the expected benefit of preventing sudden cardiac death. Fragmented wide QRS (≥ 120 ms) on a 12 lead-ECG is a sign for myocardial scar
Objective: To determine whether the presence of a fragmented wide QRS (f-wQRS) on a 12 lead ECG may risk stratify patients with severe systolic dysfunction for ventricular arrhythmias and sudden death.
Methods: The Genetic Risk Assessment of Defibrillator Events (GRADE) enrolled subjects with EF < 0.30 and ICDs and followed them prospectively for up to 5 years. f-wQRS, due to bundle branch block or paced rhythms, was defined on baseline ECG by the presence of >2 notches on the R wave or the S wave present in ≥ 2 contiguous inferior (II, III, aVF), lateral (I, aVL, V6) and anterior (V1 to V5) leads. Freedom from appropriate ICD shocks and survival were evaluated in patients with and without f-wQRS.
Results: Median follow-up on 911 patients (82% male, 87% white, 71% ischemic, age 63 ± 12 years, EF 0.21 ± 0.06, NYHA class 2.2 ± 0.6) was 27 ± 16 months. Patients with f-wQRS (N=471) and those without f-wQRS (N=440) had similar baseline characteristics. Patients with f-wQRS in more than one territory (N=277) had more appropriate ICD shocks compared to those with f-wQRS in one territory and those without f-wQRS [48 months, 40% vs 28% vs 23%, log rank p=0.02; Figure]. In multivariate analyses adjusting for age, gender, race, etiology of cardiomyopathy, f-wQRS and f-wQRS in more than one territory were independently associated with ICD shocks with p=0.001 and p=0.003, respectively. F-wQRS had no effect on survival.
Conclusions: F-wQRS provides a simple electrocardiographic tool that may complement EF to risk stratify patients with severe systolic dysfunction for the occurrence of ventricular arrhythmias.
- Ventricular arrhythmia
- Implantable cardioconvert defibrillator
- Sudden cardiac death
- © 2011 by American Heart Association, Inc.