Abstract 10820: QRS Duration is a Risk Factor for Life Threatening Ventricular Arrhythmias in Children with Dilated Cardiomyopathy
Background: The risk of sudden death in children with dilated cardiomyopathy (DCM) has been estimated < 1% annually. These data are based on sudden death incidence and may underestimate life threatening arrhythmias (LTA). The objective of this study was to assess the incidence of and identify risk factors for LTA in children with DCM.
Methods: We conducted a retrospective chart review of 183 children at a single center with the diagnosis of DCM from 2000-2011. We collected data on demographics, medications, symptoms, functional status and diagnostic studies. LTA was defined as a hemodynamically significant ventricular arrhythmia or ventricular tachycardia with a rate > 200 bpm. Risk factors for developing LTA were identified with univariate analyses. Prediction model was constructed with multivariate logistic regression and ROC curve.
Results: Ventricular arrhythmias were found in 36 patients. Of these, 22 had LTA, representing an annual rate of 5.7%. Outpatient LTA occurred in 9 subjects, or 5% of total patients. The predictors of outpatient LTA were longer QRS duration (p = 0.003) and thicker left ventricular posterior wall (LVPW) (p = 0.04). Only QRS duration remained significant in multivariate logistic regression (OR = 1.4 for each 10 msec increase, 95% CI = 1.1-1.9, p = 0.01). A prediction model for outpatient LTA using QRS duration corrected for gender and age yielded an area of 0.86 under the ROC curve (figure). In children who experienced inpatient or outpatient LTA, risk factors included longer QRS duration (p = 0.01), thicker LVPW (p = 0.03), and less frequent use of anti-arrhythmic (p = 0.03) or heart failure medications (p = 0.02). Long QRS duration remained the only significant risk factor in multivariate logistic regression (OR = 1.4, 95% CI = 1.1-1.8, p = 0.008).
Conclusion: In children with DCM, the rate of LTA is many times greater than that of SCD. Prolonged QRS duration is a strong risk factor for LTA in this population.
- © 2012 by American Heart Association, Inc.