Most pulmonary arteriovenous malformations are in the base of the lungs; thus, while upright, blood flow is redistributed to the lung base causing more shunting. While supine, less shunting occurs ...

Therefore, their appearance in the left atrium after intravenous injection suggests that pulmonary vasodilation ... In practice, an intracardiac shunt cannot be definitively excluded in a small ...

This results in a communication between the left and right atrium directly causing a left to right shunt. Over time, pulmonary hypertension can develop causing right heart enlargement and eventual ...