Cardiac myocytes loose their characteristic pattern of beating under these culture conditions. Congestive cardiomyopathy is the most common cardiac defect that occurs with iron overload, but other problems have been described including pericarditis, restrictive cardiomyopathy, and angina without coronary artery disease. The integrated backscatter of the interventricular septum and posterior wall are higher than normal, perhaps due to iron deposition. The physical examination is surprisingly benign even in patients with heavy cardiac iron deposition. Once evidence of cardiac failure appears, however, heart function rapidly deteriorates, often without response to medical intervention.
Biventricular failure produces pulmonary congestion, peripheral edema, and hepatic engorgement.
This potentially lethal cardiac complication has been reversed on occasion by vigorous iron extrication. Iron deposition in the Bundle of His and the Purkinje system impairs signal conduction from the atrial pacemaker to the ventricles. Patients sometimes die suddenly, presumably due to arrhythmias. Reports of sudden death prompted cessation of this practice. Echocardiography in children and radionuclide ventriculography in adults are the most useful non-invasive diagnostic techniques.