Stroke Prevention

Stroke Prevention in Patients with Atrial Fibrillation

If you have atrial fibrillation, your risk of stroke is about five times that of people without atrial fibrillation. Atrial fibrillation is an irregular heartbeat, also called an arrhythmia, that can increase your risk of heart failure, stroke, blood clots and other heart conditions.

A normal heart contracts and relaxes to a regular beat, but if you have atrial fibrillation, the atria (upper chambers) beat out of sync with the ventricles (lower chambers). The irregular heartbeat can cause blood to pool in your atria, causing blood clots that travel to your brain and cause a stroke.

A stroke is caused by a reduction or interruption of the blood supply to a part of the brain. The brain tissue is deprived of nutrients and oxygen, and brain cells quickly start dying.

An ischemic stroke is caused by a blocked artery. A hemorrhagic strokes occurs if a weakened blood vessel ruptures. A transient ischemic attack (TIA) causes blood flow to the brain to temporarily stop.


If you have atrial fibrillation, your risk of stroke is about five times that of people without atrial fibrillation.

Atrial Fibrillation and Blood Thinners

Patients with atrial fibrillation usually need to take anticoagulants (blood thinners) every day to prevent the formation of a thrombus clot that may travel to the brain and cause a stroke. It’s essential that patients taking anticoagulants take their medication on time and as prescribed. Missing even one dose can put a patient at risk of a stroke.

Warfarin is the oldest blood thinner on the market – it’s been available for more than 40 years. However, Warfarin can be challenging to use as the dosage may need to be adjusted depending on:

  • Other medications you take
  • How much vitamin K is in your diet
  • The amount of exercise you get
  • Illness

Newer drugs such as dabigatran, edoxaban and apixaban may be very effective, easier to use and eliminate the need for routine blood testing to manage dosage. While there’s a risk of bleeding problems on any blood thinner, bleeding is less of a risk with the newer drugs and the effects wear off faster than Warfarin, so bleeding may be less serious if it does happen. These medications may be slightly more expensive than Warfarin.

Warfarin may be a better option for patients who have kidney failure, mechanical heart valves, few or no side effects from the medication or don’t mind regular lab visits for bloodwork.


Speak with your cardiologist for more information on atrial fibrillation and blood thinners.