C63-38 Pulmonary Arteriovenous Malformations (AVMs): An Uncommon Cause of Right-to- Left Shunt

Abstract Introduction A pulmonary arteriovenous malformation (AVM) characterized by an abnormal connection between the pulmonary artery and pulmonary vein manifests as a right-to-left shunt. It causes impaired gas exchange and entrance of venous emboli in the systemic circulation, culminating in serious complications including ischemic stroke and intracranial abscess. The most predominant etiology of AVM is genetics. We are presenting an interesting case of multiple pulmonary AVMs that required embolization with significant improvement in the patient’s symptomology. Case Description A 69-year-old female with a past medical history of anxiety, COPD, fibromyalgia, and hypothyroidism, who experienced acute dyspnea on exertion, chest pain, nausea, left arm pain, and dizziness, reported to the emergency department and was found to have multiple pulmonary arteriovenous malformations on CT angiogram. Acute coronary syndrome was ruled out. She denied fever, chills, hemoptysis, and epistaxis. There was no previous history of stroke or deep venous thrombosis. An echocardiogram with agitated saline was done, and findings were consistent with a pulmonary shunt. The patient underwent an embolization procedure by interventional radiology with obvious clinical improvement. Discussion Pulmonary AVMs are uncommon vascular anomalies characterized by the direct connection of branches of the pulmonary artery and veins, bypassing the pulmonary vascular bed; hence, they create intrapulmonary right-to-left shunts. Most commonly it is associated with hereditary hemorrhagic telangiectasia, or it could be idiopathic. It presents with wide array of symptoms varying from dyspnea and chest pain to transient ischemic attacks and brain abscess. CTA of the chest is an imaging modality of choice for diagnosing pulmonary AVM. Transthoracic contrast echocardiography (TTE) is used for screening purposes to delineate the shunt and analyze risk stratification. The presence of contrast (appearing as bubbles) in the left heart after three cardiac cycles is suggestive of a right-to-left shunt in the lungs. The preferred treatment is endovascular occlusion; otherwise, surgery is definitive management. This abstract is funded by: None