Carcinoid heart disease with severe hypoxia due to interatrial shunt through patent foramen ovale

Carcinoid heart disease occurs in approximately half of patients who have carcinoid syndrome and is the leading cause of death among these patients. It is typically manifest as right-sided valvular lesions, usually tricuspid insufficiency and pulmonary valve stenosis. This case report describes the unusual presentation of a patient with carcinoid heart disease and a large right-to-left shunt through a patent foramen ovale.