Arrhythmogenic right ventricular dysplasia/cardiomyopathy versus dilated right ventricular cardiomyopathy: a problematic autopsy diagnosis?

Arrhythmogenic right ventricular dysplasia-cardiomyopathy (ARVD-C) is a rare heart condition with characteristic thinning and fibroadipose tissue replacement of the myocardium of the right ventricular wall. We have seen 20 autopsy cases with morphologic features fitting the criteria of ARVD-C in our hospital in the past 5 years. The clinical characteristics of these patients were not those described in the literatures. Two of the 20 patients died suddenly without obvious cause, and only one of the 20 patients fit the classic clinical and morphologic description of the disease. The remaining patients were chronically ill with significant comorbidities, and the pre-mortem diagnosis of ARVD-C was not suspected in all these patients. We suspect that ARVD-C could be a spectrum of morphologic changes with variable clinical manifestations, and it may be far more common than that reported in the literature. The spectrum of the morphologic changes of the right ventricular wall raise questions of the diagnostic criteria at the time of autopsy and request for more clinical pathologic correlation. Alternatively, these morphologic features may represent a specific dilated right ventricular cardiomyopathy distinct from the classic description of arrhythmogenic right ventricular dysplasia/cardiomyopathy with genetic component.