The functional defect in amyloid heart disease. The "stiff heart" syndrome.

Left ventricular performance was studied in three patients with heart failure due to amyloid deposits. The diagnosis of amyloidosis was proved by cardiac biopsy in two patients and by rectal biopsy in the third. One patient had myelomatosis, but the other two had no other identifiable disease. The investigative technique allowed simultaneous measurements of pressure and volume in the left ventricle. The functional defect with slow cardiac filling at high pressure and greatly reduced left ventricular contraction differed from that of constrictive pericarditis and other heart muscle disease. These features of a "stiff heart" are probably unique to amyloidosis and should make possible positive recognition of the condition on the basis of echocardiographic, angiographic and hemodynamic findings.