Hemidiaphragmatic paralysis: An underestimated etiology of right-to-left shunt through patent foramen ovale?

Objective To report a specific pathophysiology of hemidiaphragmatic paralysis that may result in severe hypoxemia. Design Case series. Setting Intensive care unit in a cardiology hospital. Patients The series included three patients with refractory hypoxemia in whom a diagnosis of right-to-left-shunt through a patent foramen ovale was made by contrast echocardiography. The three patients had a complete right hemidiaphragmatic paralysis. Intervention Permanent percutaneous closure of the patent foramen ovale was successfully proceeded in all cases. Main result These procedures resulted in complete normalization of arterial oxygen saturation. Conclusion To our knowledge, only three previous reports have described the association of right-to-left shunt through a patent foramen ovale and hemidiaphragmatic paralysis. Such association may be underestimated.