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.