Young stroke patients should be investigated thoroughly to look for cardiac and extra-cardiac sources of emboli. We present a patient who was investigated for a cardiac source of emboli following an ischemic stroke. She was found to have a small patent foramen ovale (PFO), but due to the late appearances of bubbles on the bubble study it was thought that this was an incidental finding. Further investigation confirmed a PAVM was the source of emboli causing her stroke.
Paradoxical embolus is a rare complication of a pulmonary arterio-venous malformation (PAVM).
Young stroke patients should be investigated for intra and extra-cardiac shunts, in particular, patent foramen ovale (PFO), ideally with a bubble study.
Consider an extra-cardiac source of embolism when bubbles are seen in arriving late into the left heart.