PFO and stroke
PFO is a patent foramen ovale, a small hole connecting the atria chambers of the heart. A PFO is found in about 25% of people.
Many cases of stroke are not explained, and are therefore labeled as cryptogenic stroke. This means they are not found to be associated with narrowing of the cerebral arteries, abnormal heart rhythm, high cholesterol, smoking or high blood pressure.
It has been attractive to consider whether having a PFO increases the risk of stroke. Perhaps a blood clot forms in a low flow vein, after a long plane trip. It finds its way back to heart, with the other venous blood, then crosses the PFO, into the arterial system, and makes its way directly to the brain? This mechanism of stroke is often speculated, but rarely proven.
Following most cases of stroke, patients are treated with antiplatelet medicines aspirin or Plavix to prevent a future stroke. Studies have shown that patients treated with anticoagulation medicine or surgical PFO closure have not had better stroke prevention than patients treated with aspirin. Although other studies are in progress, the results we have to date support the idea that most PFOs are not relevant to stroke risk.
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