Introduction: High-output heart failure is a rare form of heart failure. Possible causes include vitamin B1 (thiamine) deficiency. This vitamin plays an important role in the aminoacids energy metabolism and in the transmission of nerve impulses. Thiamine deficiency can affect the cardiovascular (wet beriberi), nervous, and immune systems.
Case report: This case report concerns a 73-year-old man with a history of alcohol abuse affected by arterial hypertension, persistent atrial fibrillation, COPD and alcoholic liver disease. Home therapy included low-dose diuretic, mineralocorticoid antagonists, anticoagulant, hypotensive drugs and oral antidiabetic drugs. Due to the occurrence of dyspnoea and progressive swelling of the lower limbs he was hospitalized. Transthoracic echocardiogram (TTE) showed mild biventricular dilatation with normal function. The Doppler study revealed moderate-severe tricuspid regurgitation (anulus dilatation) and indirect signs of an increase in pulmonary pressures. Blood tests showed a picture of cytopenia, altered hepatic synthesis indexes and high values of natriuretic peptides. He performed invasive hemodynamic evaluation with right heart catheterization which showed mild pulmonary hypertension (mPAP 28 mmHg) with normal pulmonary vascular resistance and an increase in cardiac index (CI 4.2 L/min/m2). The cardiopulmonary testing (CPET) indicated a slight reduction in functional capacity (pVo2 77% of predicted value) and initial pulmonary vascular involvement. In the following months the patient manifested haemodynamic instability with the need for intravenous diuretic therapy. At a subsequent check-up, the dosage of thiamin was performed, which was found to be deficient, so he started supplementation. In the next period the patient reported well-being and maintained euvolemia. At a hospital re-evaluation, he performed a new TTE evaluation which showed a reduction in ventricular volumes and tricuspidal regurgitation as well as a new evaluation of invasive cardiac output which showed a reduction in right sections pressure (mPAP 22 mmHg) with normalization of the CI value (2,20 L/min/m2). CPET showed almost the same results of the previous one.
Conclusion: Beriberi is a possible treatable cause of high-output heart failure. Although it is a rare pathology in Western countries, it should always be suspected in some categories of patients such as alcoholics, subjects with eating disorders and those undergoing bariatric surgery.