Patent Foramen Ovale
  • Non-Fusion of the septum secumdum and septum primum following birth.
  • Common among the general population approximately 25%.
  • Associated with cryptogenic strokes especially if large PFO, septal aneurysm,  evidence of right to left shunt, and a prominent eustachian valve.
  • Closure can be considered in selected patients with cryptogenic stroke.

Role of ECHO

  • Echo plays a crucial role in diagnosis.
  • Visualiation of a very mobile or aneurysmal intra-atrial septum may be the first clue.
  • Colour doppler may show evidence of shunt.
  • Bubble test a key test to confirm a PFO by early (less than 3 beats) bubbles crossing into the left atrium.
  • Subcostal view show evidence of very mobile intra-atrial septum.
  • Not the red colour doppler that seems to cross the intraatrial septum suggesting presence of a PFO.
  • Bubble study confirming presence of right to left shunt.
  • Note the bubbles cross early withing 3 cardiac cycles. Late bubbles would be suggestive of possible pulmonary shunt.
  • The test can also be completed during a valsalva. Occasionally this may be the only time a shunt occurs.