Thiamine and Heart Failure: Challenging Cases of Modern-Day Cardiac Beriberi.

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.