The restrictive cardiomyopathies.

In parallel with the rapidly developing interest in the diastolic properties of ventricular function in the 1970s, the restrictive cardiomyopathies have taken their place as the third major category of primary heart muscle disease. The restrictive cardiomyopathies are characterized by primary abnormalities of diastolic ventricular function with normal to near normal systolic performance and little or no increase in end-diastolic or end-systolic dimensions of either right or left ventricle. The restrictive abnormality of ventricular function can result from myocardial or endomyocardial disease, the etiologies of which may be known or unknown. Diastolic dysfunction that is essentially myocardial can be idiopathic (probably an enzymatic/metabolic disturbance), infiltrative (myocardial interstitium), or within myocardial cells (storage diseases). Diastolic dysfunction that results from endomyocardial disease is typified by endomyocardial fibrosis or the hypereosinophilic syndrome, although carcinoid, metastatic malignancies, radiation, and anthracycline toxicity may be accompanied by endomyocardial restriction. Echocardiography and Doppler ultrasound, MRI, and radionuclear techniques have been major advances in providing diagnostic precision, contributing materially to the clinical identification of the restrictive cardiomyopathies as well as discriminating certain of their etiologies.