Pulmonary arteriovenous malformations in and out of the setting of congenital heart disease.

Abstract

Pulmonary arteriovenous malformations can occur in a variety of clinical situations, including liver disease, systemic disorders, or after palliation of congenital heart disease, with serious clinical consequences. We reviewed the potential mechanisms of this condition, diagnostic tools, and clinical management. Contrast echocardiography is an important diagnostic modality, which has been shown to be more sensitive than pulmonary arteriography, especially when rapid contrast injection is used. The finding that pulmonary capillary vasodilation is observed in hepatopulmonary syndrome, in cirrhotic patients, and after congenital heart repair is strongly suggestive that an unidentified hepatic factor is involved in inhibiting the development of pulmonary arteriovenous malformations. Prompt detection and treatment of pulmonary arteriovenous malformations is of utmost importance, to prevent serious clinical consequences. It may very well be the case that the etiology of arteriovenous malformations is multifactorial. We are now investigating the role of alterations of gene expression in the vascular remodeling that results in formation of pulmonary arteriovenous malformations.