Sudden cardiac death in a young woman: tumor of the atrioventricular (AV) node or citalopram intoxication?

Atrioventricular (AV) node tumor is a very rare lesion of the cardiac conduction system. Clinically, it is associated with complete AV block and sudden cardiac death, often in apparently healthy young people. We report a case of a 24-year-old woman who developed ventricular fibrillation during sexual intercourse and died before admittance to the hospital. The woman had a medical history of depression and was treated with citalopram. At first, no macroscopic or microscopic pathologic changes were found. Toxicologic analysis showed a toxic level of citalopram in the blood. Further microscopic examination of the cardiac conduction system disclosed a tumor of the AV node. Immunohistochemical staining confirmed endodermal origin in accordance with the latest hypothesis of the pathogenesis of this tumor. It was concluded that this young woman died of cardiac arrhythmia due to the AV tumor and not from citalopram intoxication, as first suspected. This case emphasizes the importance of a microscopic examination of the cardiac conduction system in cases of sudden unexpected death, even in cases with a plausible cause and manner of death at first glance.