A case report of high-output heart failure due to arteriovenous shunt without bowel: how to address?

Background: High-output heart failure (HF) is a form of HF where patients present with a high-output state with low systemic vascular resistance. This report presents the case of high-output HF in a patient with an arteriovenous shunt and no options for oral-administered drugs. Case summary: A 70-year-old male with a terminal jejunostomy fully depending on parenteral feeding through a vena saphena magna shunt presented with symptoms of shortness of breath. Echocardiography revealed eccentric hypertrophy with reduced left ventricular ejection fraction (LVEF) and atrial fibrillation with a heart rate of 70-100 b.p.m. Cardiac magnetic resonance imaging, endomyocardial biopsy, and cardiomyopathy lab revealed no cause of HF. High-output HF based on right heart catheterization due to the arteriovenous shunt or related to irregularity due to atrial fibrillation were potential causes. As a result of his malfunctioning gastrointestinal system, the pharmacological options were limited. He was treated with captopril sublingual, initially 6.25 mg three times daily (TID) and later 12.5 mg TID, which reduced blood pressure. Electrical cardioversion to sinus rhythm was successful but did not improve LVEF. Therefore, the patient was opted for surgically reducing the blood flow through the shunt, resulting in normalization of LVEF. Discussion: High-output HF is an uncommon form of HF with an uncertain prevalence. The most common aetiologies reported in the literature are obesity, cirrhosis, and arteriovenous shunts. Sublingual administration of captopril can be an effective treatment option for HF patients unable to absorb oral-administered drugs.