Pulmonary arteriovenous fistula

Pulmonary arteriovenous fistula refers to an abnormal vascular communication formed between the pulmonary artery and pulmonary vein. A pulmonary arteriovenous fistula allows pulmonary arterial blood to bypass gas exchange and directly enter the pulmonary vein and then the systemic circulation. This results in lower oxygen content in the blood flowing into the systemic circulation, leading to exertional dyspnea, cyanosis, and other symptoms.