Pulmonary Arteriovenous Malformation

Pulmonary arteriovenous malformation (PAVM), a rare pulmonary condition, is defined as a structurally abnormal communication between the pulmonary artery and pulmonary vein, creating a pathologic intrapulmonary right-to-left shunt. This, in turn, impairs regular gas exchange and filtration of systemic venous blood. PAVMs are also known as pulmonary arteriovenous fistulae, pulmonary arteriovenous aneurysms, and pulmonary hemangiomas. These lesions were initially described by Churton in 1897 and were later identified to be associated with hereditary hemorrhagic telangiectasia (HHT) in 1938. A vast majority of patients with PAVMs can be asymptomatic; however, patients that remain undiagnosed can later present with life-threatening complications such as ischemic stroke, myocardial infarctions, cerebral abscesses, massive hemoptysis, and hemothorax. Although there is a relatively low incidence of this condition, it is essential to consider in the differential diagnosis for patients presenting with epistaxis, hypoxemia, and dyspnea with exertion.