Long-term follow-up of a child with idiopathic restrictive cardiomyopathy.

A ten-year-old male with palpebral edema was proved to have a restrictive hemodynamic pattern by cardiac catheterization. Sequential echocardiographic examination revealed uniformly depressed left ventricular diastolic properties, well-maintained left ventricular systolic function, and a progression of obliterative change of the left ventricular cavity. Myocardial biopsy at 17 years of age disclosed a normal endocardium and marked interstitial fibrosis of the myocardium. Consequently, a decrease of cardiac output and a marked biatrial enlargement have developed in association with persistent atrial fibrillation.