Acute viral myocarditis, alcohol abuse, pregnancy., thyroid disease, cocaine use, and chronic uncontrolled tachycardia cause dilated cardiomyopathy- Harrison 17th/l481 Restrictive Cardiomyopathies (RCMs) - Harrison 17th/1485-86The hallmark ofthe restrictive cardiomyopathies (RCMs) is abnormal diastolic function ; the ventricular wails are excessively rigid and impede ventricular filling. In late stages systolic function is also impaired. Myocardial fibrosis- livpertropby. or infiltration due to a variety of causes is responsible. Myocardial involvement with amyloid1 is a common cause of secondary restrictive cardiomyopathy although restriction is also seen in the transplanted heart, in hemochromatosis, glycogen depositiong, endomyocardial fibrosis, sarcoidosis , hypereosinopbillc disease., and scleroderma; following mediastinal irradiation; and in neoplastic infiltration and myocardial fibrosis of diverse causes. In many of these conditions, particularly those with substantial concomitant endocardial involvement, partial obliteration of the ventricular cavity by fibrous tissue and thrombus contributes to the abnormally increased resistance to ventricular filling. Thromboembolic complications are frequent in such patients The inability" of the ventricles to fill limits cardiac output and raises filling pressures; thus, exercise intolerance and dyspnea are usually prominent. As a result of persistently elevated systemic venous pressure, these patients commonly have dependent edema, ascites, and an enlarged, tender, and often pulsatile liver . The jugular venous pressure is elevated and does not fall normally (or may rise) with inspiration (KussmauTssignf