This can be exacerbated by acute increases in pulmonary vascular resistance such as those that occur during breath-holding, crying, or the Valsalva maneuver. Paradoxical emboli through a patent foramen ovale can cause a constellation of neurologic symptoms such as visual disturbance, weakness, hemiplegia, or slurred speech. These findings include fixed splitting of the second heart sound, a pulmonary ejection murmur, and a low-pitched diastolic rumble at the lower right sternal border. There are no specific laboratory tests for patent foramen ovale. Occasionally, an aneurysm of the atrial septum is associated with a patent foramen ovale.
Subcostal views are particularly proficient in imaging the atrial septum.
For patients undergoing sitting neurological procedures, TEE is recommended if standard echocardiography is not adequate. This places the high-velocity flow farther from the origin of the beam. Bubble contrast echocardiography may be needed. Cardiac catheterization may rarely be indicated to evaluate a patient for a patent foramen ovale and to assess shunting if this cannot be established by non-invasive means. The only other indication for cardiac catheterization might be if transcatheter closure of the patent foramen ovale is to be performed.