Cardiac magnetic resonance and "augmented" right-to-left intracardiac shunting through a patent foramen ovale.

Platypnea-orthodeoxia is an uncommon condition characterized by the development of hypoxia and breathlessness in the upright posture, relieved by resuming a supine position. First described in 1969, the condition has since been associated with intracardiac and intrapulmonary shunts, liver disease and a host of other conditions. We report an unusual case of episodic breathlessness and hypoxia cured by percutaneous cardiac intervention and discuss the evolving role of cardiac magnetic resonance imaging in the demonstration of functional distortions of cardiac and mediastinal anatomy that may not be as well characterized by other available imaging modalities.