OBJECTIVEIt is difficult to differentiate the causes of dilated cardiomyopathy only by clinical evaluation and image analysis. Pathomorphologic examinations on diseased hearts may help to improve the diagnosis accuracy.

METHODSFifty-six extransplanted hearts from June, 2004 to June, 2006 were examined. Gross and histopathological findings were recorded, photographed and final pathological diagnosis was compared to clinical diagnosis.

RESULTSDilations were caused by sole myocardial wall damage in 38 (67.9%) of the 56 patients, including 19 primary dilated cardiomyopathy, 9 arrhythmogenic right ventricular cardiomyopathy, 1 non-compaction cardiomyopathy, 6 ischemic cardiomyopathy, 1 alcoholic cardiomyopathy, 1 hypertensive cardiomyopathy and 1 giant cell myocarditis. The clinical and pathological diagnoses were different in 15 cases (39.5%). The most discrepancies were arrhythmogenic right ventricular cardiomyopathy (77.8%), ischemic cardiomyopathy (83.3%), and giant cell myocarditis (100%).

CONCLUSIONSThis pathological study of recipient hearts showed a high portion of patients with arrhythmogenic right ventricular cardiomyopathy and ischemic cardiomyopathy were misdiagnosed as primary cardiomyopathy. Correct diagnosis of primary cardiomyopathy needs to rule out possible secondary causes of myocardial dilation.