Some previously neglected examples of arrhythmogenic right ventricular dysplasia/cardiomyopathy and frequency of its various reported manifestations

Four patients are described with either parchment-like thinning or partial but extensive myocyte depletion with severe fatty or fibrofatty infiltration of the free wall of the right ventricle in its outflow tract, including 2 previously reported patients who also had focal parchment-like thinning of the left ventricular free wall. Three had documented ventricular tachycardia, and the remaining patient had sudden death as his first and only manifestation of heart disease. Three patients had severe heart failure: in 1, it was fatal, and the other 2 underwent cardiac transplantation. Necropsy cases of parchment-heart syndrome before 1980 are reviewed, as well as large series of cases with arrhythmogenic right ventricular dysplasia (ARVD) reported subsequently. It is suggested that ARVD is not an ideal name for this condition, because malignant ventricular arrhythmias are not universal, the left ventricular free wall and/or ventricular septum are sometimes involved, and the name "ARVD" neglects the fact that severe heart failure may be prominent in these patients. The right ventricular wall can be thin or parchment-like, or it may not be thinned but consist mainly of adipose tissue with or without focal fibrous tissue and a few islands of myocytes. Nevertheless, because the name "ARVD" has been commonly used and recognized for >30 years, it is probably best retained for this condition.