- We describe a case of a young adult in whom sudden cardiac death due to ventricular fibrillation was the presenting manifestation of an adrenocortical carcinoma. The arrhythmia was precipitated by severe hypokalemia induced by the aldosterone-secreting tumor. Sudden death has not been previously described as a manifestation of this adrenal neoplasm. Unexplained persistent hypokalemia after resuscitated sudden death (especially when combined with hypertension (should prompt investigation for an underlying secondary hypertension, particularly adrenal pathology. Adrenocortical carcinoma should be considered in the differential diagnosis of unexplained sudden death associated with unexplained hypokalemia.