Abstract 13776: QRS Duration and Epsilon Wave on Surface Electrocardiogram Are Markers of Disease Severity in Patients With Ebstein Anomaly
Background: In Ebstein anomaly the main morphological feature is apical displacement of the functional tricuspid valve annulus causing tricuspid regurgitation and dilation of the “atrialized portion”of the right ventricle (RV). We studied the electrocardiograms (ECGs) of a series of patients with Ebstein anomaly referred for cardiac magnetic resonance (CMR) imaging. Our goal was to determine if ECG parameters correlated with RV morphological features seen at CMR.
Methods: We digitally analyzed ECGs in 66 patients (aged 1 to 63 years) with isolated Ebstein anomaly, comparing 14 ECG parameters with RV volume and function obtained by CMR. The anatomical RV was divided into a functional RV (from the tricuspid valve leaflet margins to the pulmonary valve) and an atrialized RV (from the anatomic tricuspid valve annulus to the tricuspid valve leaflet margins).
Results: Right bundle branch block was common (70%). In 9 patients (14%) an epsilon wave was noted. The relation between QRS duration with anatomical right ventricular volume and functional right ventricular ejection fraction is shown in Figure 1. In the 9 patients with an epsilon wave, a significantly higher atrialized RV volume was measured (80.3 ml/m2 vs. 51 ml/m2, p = 0.03). Patients with normal QRS duration had significantly lower indexed, diastolic, anatomical RV volume (150 ml/m2 vs 246 ml/m2, p < 0.0001).
Conclusions: Our study represents the first systematic analysis of the ECG features in patients with Ebstein anomaly. We show that QRS duration prolongation is correlated with RV dilation and inversely associated with functional RV systolic function. We propose that the epsilon wave identifies a subset of patients with severe delay in depolarization of the atrialized right ventricular myocardium, which may serve as a substrate for ventricular arrhythmias. Further study will elucidate how best to integrate such ECG findings within standardized clinical management planning for patients with Ebstein anomaly.
- © 2010 by American Heart Association, Inc.