QT intervals in metabolic dilated cardiomyopathy

Objectives The present study determined the prevalence of dilated cardiomyopathy together with prolonged corrected QT (QTc) intervals in children. The study also examined whether an association exists between prolonged QTc intervals and ventricular dysrhythmia in a patient cohort with dilated cardiomyopathy. Background The morbidity and mortality for pediatric patients with dilated cardiomyopathy remains high and is a clinical challenge. The patient population includes a significant number of Hutterite patients with metabolic disease associated with dilated cardiomyopathy. Methods Thirty-eight pediatric patients with dilated cardiomyopathy were reviewed for the presence of prolonged QTc and dysrhythmias. Eleven patients had a metabolic etiology for their dilated cardiomyopathy. Results Thirty-six per cent of the patient cohort had a long QTc interval. After 50 months of follow-up, the probability of survival for a child with a long QTc interval was approximately 50%. The probability of survival for a child with a normal QTc interval was 72%. Seventy per cent of the patients who died had a metabolic etiology for their dilated cardiomyopathy and a long QTc. Conclusions Dilated cardiomyopathy may be associated with a prolonged QTc and may increase the patient's risk for sudden death. The presence of a metabolic etiology for dilated cardiomyopathy increases the risk of death.