Idiopathic cardiomyopathy in children.

T HIS REPORT describes a group of children, ages 3 to 13, who present unusual cardiac findings suggestive of the earliest stages of idiopathic cardiomyopathy. Idiopathic cardiomyopathy refers to an enlargement of the heart without apparent cause, but primarily due to muscular hypertrophy. The process is dominant in the left ventricle, but can involve other chambers, either primarily or secondarily after left ventricular failure. When hypertrophy involves the interventricular septum, there may be obstruction to left ventricular outflow and aggravation of the myopathic state. In the cases to be described, the diagnosis has been made largely on clinical grounds. The most important criteria are an abnormal left ventricular impulse with cardiomegaly, an abnormal jugular venous pulse, and an acquired characteristic murmur. Since most of the patients are asymptomatic and all are living, no autopsy or biopsy studies are presented. In the past, reports have been concerned with the late stages of cardiomyopathies. -4 The majority of patients were adults who presented with congestive failure, and documentation was frequently made by autopsy. It is clear that little is known of the early natural history of the cardiomyopathy disease complex. It is our speculation that the cardiomyopathies run a protracted course measured best in decades rather than years. This study deals with what may be early manifestations of that process.