Dual mechanism platypnea-orthodeoxia syndrome from severe right coronary artery stenosis and a patent foramen ovale

Abstract

Platypnea-orthodeoxia is a rare clinical syndrome characterized by hypoxemia induced during upright posture. Multiple mechanisms have been proposed to explain this clinical entity, usually involving posture-provoked intracardiac or transpulmonary shunting. In many cases, however, a single etiology may not be evident, and multiple factors are likely contributory. We herein describe an unusual and novel case of platypnea-orthodeoxia caused by the physiologic interaction between a severe proximal right coronary artery stenosis and a large patent foramen ovale. Percutaneous stenting of the right coronary artery and transcatheter closure of the patent foramen ovale during the same setting resulted in complete resolution of the patient's symptoms.