Patients with an arteriovenous shunt is at risk for neurologic complications. Other peripheral sites would also be at increased risk of embolic lesions.
Conditions associated with a pulmonary arteriovenous shunt:
(1) hereditary hemorrhagic telangiectasia (HHT, Rendu-Osler-Weber Syndrome)
(2) hepatopulmnary syndrome (include hepatosplenic schistosomiasis)
(3) congenital vascular disorder
(4) iatrogenic shunt in congenital heart defect after partial or complete cavopulmonary anastomosis
(5) healthy individuals (usually small)
A shunt can be detected by transthoracic contrast echocardiography (TTCE) with agitated saline.
Neurologic complications occur when there is a paradoxical embolus which can result in TIA or stroke.
The risk for neurologic complications increases with:
(1) the size of the shunt, which also affects flow through the shunt.
(2) venous thrombo-embolic conditions
A small shunt may not require intervention.
Differential diagnosis:
(1) patent foramen ovale
(2) endocarditis
