Pulmonary Arteriovenous Fistula as a Cause of Chronic Hypoxemia in a Woman with Preserved Myocardial Function: Case Report

Pulmonary arteriovenous fistulas are rare within the spectrum of vascular malformations. Dyspnea and fatigue are the most common symptoms. Their etiology is congenital in 90% of cases, and almost 85% are associated with Osler-Weber-Rendu syndrome (hereditary hemorrhagic telangiectasia). More than half of patients are asymptomatic, approximately 40% have neurological manifestations (cerebrovascular events, headaches, and seizures), and only 10% report dyspnea and cyanosis. This is a 50-year-old woman who presented with progressive dyspnea, dizziness, and fainting with oxygen saturation of 82% for a 6-month duration. She attended a private hospital where a pulmonary CT angiography was performed, which reported a dilatation of the right pulmonary trunk with an apparent fistula. She was referred to our cardiology center, where a sinus electrocardiogram reported a normal heart rate with no signs of hypertrophy. Pulmonary computed tomography (CT) was performed, ruling out pulmonary thromboembolism. However, a fistula was found between the right basal pulmonary artery and the middle lobe to the ipsilateral pulmonary vein, causing a shunt of deoxygenated blood to the systemic circulation, causing desaturation in the patient (right to left). Echocardiographic scanning revealed no hemodynamic abnormalities in the cardiac chambers. Until the 1980s, treatment options in these cases were partial or total lobectomies. Percutaneous occlusion devices, primarily coils, began to be used with varying degrees of success. However, the choice of treatment option depends on the clinical presentation, the severity of symptoms, and the patient's wishes.