Atrial fibrillation increases the risk for stroke. So stroke prevention is an important part of treatment for atrial fibrillation.
Atrial fibrillation is a type of abnormal heart rhythm. The heart has 4 chambers: 2 upper atria and 2 lower ventricles. Atrial fibrillation causes the atria to quiver or “fibrillate” instead of contracting normally. The disorganized signal spreads to the ventricles, and it causes the ventricles to contract irregularly. The contraction of the atria and the ventricles is no longer coordinated. So the amount of blood pumped out to the body will vary with each heartbeat. The ventricles may not be able to pump enough blood to the body.
Taking medicine to thin the blood helps prevent stroke, but it also increases your risk of bleeding. You may have signs of excess bleeding if your blood isn’t clotting enough. You may have these symptoms:
An unusually severe headache might also be a sign of bleeding in the brain.
Doctors use a risk based scoring system to decide whether you need anticoagulant medicines to help prevent stroke. The scoring system takes into account other risk factors for stroke and assigns each a point value. These risk factors include:
Your doctor will work closely with you to find the right medicines for you to help prevent stroke. Your doctor will consider both your health history and your preferences.
Your doctor may prescribe blood thinners to help prevent clots. Some of these medicines include:
These types of medicines help to prevent blood clots in different ways:
If you have risk factors for stroke, you will likely need anticoagulation medicines. These medicines require careful monitoring. Your healthcare provider will discuss this with you in detail. You want the blood to clot a little less than it would normally, to help prevent stroke. But you don’t want to stop clotting too much, which can cause extra bleeding.
With warfarin, your healthcare providers use blood tests to make sure the blood is clotting the right amount. They can measure clotting with a PT test (prothrombin time test). This test is usually read as a person’s international normalized ratio (INR). If your INR is too high, your healthcare provider may lower the amount of the medication. If your INR is too low, your healthcare provider may increase the amount of the medicine.
A device called a left atrial appendage occluder is now available in some circumstances, to prevent stroke without having to use lifelong blood thinner. This device occludes the left atrial appendage where most blood clots form. This device is not appropriate for everyone. It is generally considered in those who are at high risk for stroke as well as high risk for bleeding.
There are risks of using medicines that help prevent blood clotting and stroke. These medicines also increase the risk of bleeding. This bleeding can occur anywhere in the body. It can be very dangerous if it happens in the digestive tract. Bleeding inside the brain is also very dangerous. This can actually cause a stroke, something the medicine was supposed to help prevent. People who take anticoagulation medicines like warfarin, dabigatran, rivaroxaban, edoxaban, or apixaban are at greater risk of bleeding than people taking medicines like aspirin.
Another risk is that a person might not be taking enough warfarin. This can lead to another blood clot and stroke.
Your healthcare team will work hard to make sure you are getting the right amount of medicine for you by balancing these risks. He or she will only prescribe medicines if the benefits of stroke prevention are greater than the risks of extra bleeding.
Your doctor may give you additional instructions about managing your atrial fibrillation. Make sure all your doctors, dentists, and pharmacists know if you are taking medicines to prevent clots. Ask your doctor before taking any new medicines, even if they are over the counter. These may interact with your anticoagulation medicines. Talk with your doctor about your diet. Certain foods like leafy green vegetables can change your INR. You don’t have to avoid these, but you need to keep the amount of them that you eat about the same from day to day.
Your doctor might make other recommendations about how to lower your risk for stroke. These might include:
See a doctor right away if you have any of the following signs:
Plan to see your doctor soon if your symptoms are slowly getting worse. Also see your doctor if you have any new mild symptoms or side effects.
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