Thiamine deficiency as a rare cause of reversible severe pulmonary hypertension

In developed countries, the incidence of cardiac beriberi is rare. It can lead to high output cardiac failure and pulmonary hypertension. We hereby report an atypical case of beriberi heart with reversible right heart failure and severe pulmonary hypertension. Thiamine deficiency can cause reversible pulmonary hypertension, and it must be included in the differential diagnosis in patients with high risk of nutritional deficiency.