New-onset heart failure in children in the absence of structural congenital heart disease.

The dramatic advances in the operative and perioperative care of children with major forms of congenital heart disease have resulted in excellent shortand medium-term outcomes for the most severe forms of heart disease, including those with so-called single-ventricle physiology. This represents one of the great advances in pediatrics over the last 3 decades. A corollary of these observations is that some of the worst outcomes for children with heart disease are now observed in those with cardiomyopathy (whether acquired or congenital). This fact has drawn focus on heart muscle disease as an important cause of morbidity and mortality in children.