15. “How long do I have to be in A-Fib before I develop a clot and have a stroke?”
When blood is stagnant and not being pumped out of the left atrium, a clot can form. When the left atrium starts beating again, this clot can be pushed downstream into the left ventricle which then pumps this clot into the legs, lungs, brain or other organs causing an ischemic stroke.
But these clots aren’t formed instantly. It takes a while for stagnant blood to pool and clot. For example, if you have a ten minute attack of A-Fib, conventional wisdom says it’s unlikely a clot will develop.
The American College of Chest Physicians recommends that anticoagulation therapy be started after two days. But not everyone is in agreement that it takes at least two days of being in A-Fib for a clot to form. Dr. Antonio Gotto in Bottom Line Health says it takes one day for a clot to form, “There’s an increased risk for stroke if the irregular heartbeat continues for more than 24 hours.” (Some doctors are of the opinion that it takes as little as 5 1/2 hours of A-Fib for a clot to develop.)
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Last updated: Monday, May 8, 2017