Primary cardiac angiosarcomas are rare malignant tumors with a very poor prognosis. We present a case of a 48-year-old man with no previous cardiac history who developed an incessant focal atrial tachycardia complicated by tachycardia-mediated cardiomyopathy as a consequence of cardiac angiosarcoma. (Level of Difficulty: Beginner.).

Cardiac beriberi, or heart failure due to thiamine deficiency, is considered rare in the developed world. The diagnosis is often only considered in limited populations such as those with chronic alcoholism. Alternatively, the disease can be mislabeled as "alcoholic cardiomyopathy" or "nonischemic cardiomyopathy." The following 2 cases illustrate the need to expand our vigilance to other at-risk populations.