Written by Karen Shackelford | Published on February 17, 2015
Medically Reviewed by George T. Krucik, MD, MBA on February 17, 2015
Learn why women with AFib are at higher risk for stroke.
Those with irregular heart rate, known as atrial fibrillation (AFib), are at greater risk for a stroke than those with a regular heart rhythm. And although the exact reason is still unknown, women with AFib are more likely to have a stroke than men.
AFib, Strokes, and Risk Factors
The heart has four chambers, and the heartbeat normally begins in the chamber called the right atrium. The heart rhythm of someone with AFib can be described as chaotic. Instead of beginning in a small area of the right atrium called the sinus node, competing electrical impulses cause the right atrium to quiver. And rather than one impulse traveling from the atria to the ventricles, many electrical impulses compete to travel down the same pathway. This causes the ventricles to beat rapidly.
When the heart beats rapidly and irregularly, the heart chambers aren’t able to completely fill with blood. As a result, they aren’t pumping as much blood into the body. Blood clots can form when blood pools in the atria. A clot can then circulate to the rest of the body. A stroke occurs when a blood clot travels from the heart to the brain.
The risks of stroke and developing AFib increase with age. High blood pressure, diabetes, and congestive heart failure are all risk factors for a stroke. Having a heart attack or blood clot also increases the risk.
Stroke risk factors can be calculated with the “CHADS VASc” scoring system. If you have one or more of these risk factors, your doctor will probably prescribe a blood thinner:
C congestive heart failure
A age 75 years or older
V vascular disease
A age (ages 65-74)
Sc female gender
The two most important risk factors are age and history of a stroke or ministroke.
Women and Strokes
According to the National Institutes of Health, AFib causes one out of every four strokes after age 80. The chances of having a stroke with AFib are more prevalent for women.
One study found that compared to men, women had:
•twice the risk of stroke
•more severe strokes
•three times greater a chance of dying from a stroke
Another study looked at the history of 70,000 patients with atrial fibrillation from 1997 to 2006. Simply being female increased the likelihood of stroke. The risk of stroke for women increased even more when other risk factors like high blood pressure or age greater than 65 were taken into consideration.
The exact reason women have a higher risk for stroke than men is still unknown, but certain precautions can be made to reduce the risk.
Reducing the Risk of Stroke
Strokes in those with AFib tend to be more severe than strokes in those without AFib.
But most strokes that occur as a result of AFib may be preventable through the use of blood thinners or anticoagulants.
Talk to your doctor before taking any kind of blood thinner. Frequent blood tests may be necessary since bleeding can sometimes occur. You also may need to make certain dietary changes. The use of blood thinners is the most important measure women with AFib can take to reduce the risk of stroke.