Right-to-left shunting after lobectomy through a patent foramen ovale.

Hypoxia and dyspnea after lung resection may be caused by a variety of factors. One entity that has been rarely described is right-to-left shunting across an interatrial communication in the absence of elevated right-sided pressures. We describe the occurrence of clinically evident right-to-left shunting after lobectomy in a patient with a patent foramen ovale and suggest that two-dimensional contrast echocardiography is a useful and minimally invasive means of diagnosing what may be a more common entity than was previously recognized.