Hypoplasia of the right ventricular myocardium with ventricular tachycardia.

A 20-year-old woman died suddenly after having had recurrent ventricular tachycardia for five years. An ECG showed two distinct varieties of ventricular tachycardia, both characterized by left bundle-branch block. Pathologic examination showed what we considered to be a type of Uhl's anomaly. Most of the compact layer of the right ventricle was replaced by fat, with the trabeculated areas intact but showing severe fibrosis and chronic inflammation. Patches of such degeneration were also found in the septum and the left ventricle. The conduction system disclosed a septated bundle of His.