In this paper, we report the autopsy findings of a 42-year-old White male who was found deceased at his home by his brother in the early morning hours with a history of excessive alcohol consumption 1 day before his death. A medical record review revealed chronic alcohol use with alcohol dependence syndrome, hypertension, and cardiac arrhythmias by electrocardiogram 2 years prior. External examination revealed only a single bruise on the forehead. Internal examination revealed changes associated with chronic alcohol abuse and mild atherosclerosis. The lack of a cause of death at autopsy resulted in a dissection of the cardiac conduction system and the detection of a small cystic lesion at the atrioventricular node region. Microscopic examination revealed a cystic tumor of the atrioventricular node and fibromuscular dysplasia of the coronary artery branches near the sinoatrial and atrioventricular nodes. Based on the case history and autopsy findings, death was attributed to a fatal cardiac arrhythmia due to cystic tumor of the atrioventricular node with fibromuscular dysplasia of the coronary artery branches near the sinoatrial and atrioventricular nodes a possible contributing factor.