Oncocytic cardiomyopathy of infancy with Wolff-Parkinson-White syndrome and ectopic foci causing tachydysrhythmias in children.

Two female infants, ages 6 months and 13 months, were first seen in the newborn period with supraventricular tachycardia associated with Wolff-Parkinson-White syndrome. One infant had echocardiographic and angiographic evidence of diffuse cardiomyopathy and died suddenly at home. The other infant was seen initially at 13 months of age with refractory ventricular tachycardia and died following surgical resection of arrhythmogenic foci on the left and right ventricles. Autopsy showed diffuse patchy oncocytic cardiomyopathy in both instances. Serial histologic sections of the cardiac conduction system showed oncocytic involvement of the atrioventricular (AV) node, His bundle, and bundle branches. Both infants had interruption of the anulus fibrosus by oncocytic cells at several sites, resulting in multiple accessory AV and nodoventricular connections. Additionally, patient No. 1 had an accessory AV connection by oncocytic cells in the fatty fibrous tissue of the left AV sulcus. To our knowledge, this is the first report of multiple accessory AV connections of oncocytic cells seen during histologic study. In addition, both infants had oncocytic involvement of the exocrine and endocrine glands. This report discusses the clinicopathologic correlations in these two patients, the literature on oncocytic cardiomyopathy, and the types of dysrhythmias found in these patients and their management.