Dilated cardiomyopathy in children

Pediatric cardiomyopathies are infrequent diseases of the cardiac muscle, with an annual incidence of 1.1 to 1.2 per 100,000 children. Dilated cardiomyopathy (DCM) is the predominant form, characterized by ventricular dilatation and systolic dysfunction. Etiologies are multiple, with at least 50%-70% of cases being idiopathic. When assessing a child with DCM, secondary potentially reversible causes must be ruled out. The main diagnostic tool is the echocardiogram which allows the identification of cardiac phenotype, to establish the degree of functional compromise, and response to medical therapy. Prognosis is limited but more favorable in infants younger than 1 year at the onset, post myocarditis, or with a lesser degree of ventricular dysfunction. At least 20% of patients may recover ventricular function in the first 2 years after the onset and 40%-50% may die or need heart transplant in the first 5 years. Medical therapy is mainly based on adult experience with limited scientific evidence in children. Heart transplant is the therapy of choice in patients with end-stage disease, with excellent short- and medium-term survival. A significant proportion of patients may require stabilization on the waiting list, including the use of mechanical circulatory support as a bridge to transplantation. The purpose of this revision is to update the available information on etiology, physiopathological mechanisms, prognostic factors, and management of DCM in children.