[The morphology of the myocardium in the Wolff-Parkinson-White syndrome].

Myocardium of the right atrium from 5 patients with the above syndrome was studied at the light and EM level. Apoptotic degeneration of myocytes was demonstrated for the first time. The alterations observed may be secondary and due mainly to microcirculatory disturbances produced by tachyarrhythmia which appear during the excitation waves circulation. Metabolic changes and ischemization of myocytes may trigger the program of cell death (apoptosis) this aggravating the myocardium state and producing widespread fibrosis. These changes may serve a cause of lethal arrhythmia and sudden death of patients.