Iron in the heart: Etiology and clinical significance

Abstract

Nineteen of 135 patients (four with idiopathic hemochromatosis and 131 with chronic anemia) had cardiac iron deposits (CID). The ventricular CID were grossly visible in nine patients and microscopically visible only in ten patients. Atrial CID were extensive in six patients with extensive ventricular CID, but in the other thirteen patients atrial CID were minimal. Iron deposits in cardiac conduction tissue were minimal and always less than in working myocardium. Every patient who had iron in the myocardium also had iron in other organs and tissues. Nine patients had pigmentary cirrhosis which was associated with anemia and exogenously administered iron in six and unassociated with anemia in three (idiopathic hemochromatosis). Each of seven patients with extensive CID without other cardiac disease had clinical evidence of cardiac dysfunction, and five had chronic congestive cardiac failure. In contrast, cardiac failure, usually transient and mild, occurred in one of six patients with minimal CID and in eight of eighty-four patients without CID. Of the nineteen patients with CID, three had idiopathic hemochromatosis; 16 had chronic anemia. Each anemic patient who received more than 100 units of blood had extensive CID unless chronic bleeding diatheses coexisted. Each anemic patient with extensive CID who received less than 100 units of blood had hepatic cirrhosis. In conclusion (1) grossly visible CID are always associated with cardiac dysfunction and usually chronic cardiac failure; (2) CID, usually extensive, occur in patients with idiopathic hemochromatosis; (3) extensive CID occur in patients who receive more than 100 units of blood unless bleeding diatheses coexist; (4) patients with chronic anemia and hepatic cirrhosis who receive less than 100 units of blood also may have extensive CID; (5) CID initially occur in ventricular myocardium, and are usually more extensive in ventricular than in atrial myocardium; (6) CID are always more extensive in working than in conducting myocardium; (7) supraventricular arrhythmias correlate with the extent of CID in atrial myocardium. Thus, the iron heart is not a strong heart but a weak one.