If you have atrial fibrillation, you probably already know that you may be at higher risk of having a stroke.
Now, a new method is being tested to determine which people with Afib are at higher risk by researchers from Johns Hopkins University School of Medicine.
Atrial fibrillation is a heart condition that makes the upper left atrium (chamber) of your heart beat in an irregular rhythm that is faster than normal.
This rapid rhythm keeps the heart from beating as strongly as it should. This can reduce how much blood is pumped out into the body, and cause blood to pool inside the heart.
Blood that is not moving tends to clot, so Afib can result in small clots forming inside the chamber of the heart. If one of these clots leaves the heart and travels to the brain, it can cause a stroke.
A stroke happens when something such as a blood clot prevents blood from getting to the brain. With the supply of nutrients and oxygen cut off, cells in the brain can start to die.
When brain cells die, the part of the body controlled by that area of the brain may stop working, such as losing muscle control, memory or the ability to talk.
Researchers at Johns Hopkins used a standard MRI to check the hearts of 149 men and women who have Afib. They used special motion tracking software to evaluate the motion of the heart when it was beating irregularly.
The research team was able to identify changes in the muscles of the left atrium of some of the study participants that increased the risk of stroke for those patients.
Patients who are believed to be at higher risk of stroke are often prescribed blood thinning medications such as warfarin or other, newer blood thinners.
But there are risks associated with the use of blood thinners, including dangerous or life-threatening bleeding. So knowing whether blood thinners are truly necessary for a particular patient could significantly improve patient care.
The researchers hope to expand on their work to some day have an effective test to show which Afib patients are at higher risk of stroke. Such a test would reduce the number of patients who would need to take blood thinners.
These preliminary results are a first step toward that goal.
But the cost of adding an MRI scan to the current standard evaluation for stroke risk is prohibitive and the test is not conclusive enough to warrant a change to the standard methods of determining stroke risk at the present time.
Doctors currently use a mathematical formula to calculate the risk of stroke for people with Afib. The assessment tool estimates risk based on sex, age and medical history of heart failure, high blood pressure, vascular disease and diabetes.
The test also takes into account whether you have had a previous stroke, a transient ischemic attack (TIA or mini-stroke) or blood clot.
If you have Afib, you can find an easy-to-use calculator to gauge your stroke risk on the mdCalc website.
The Johns Hopkins researchers did not suggest a timeline for when MRI might be added to the standard stroke-Afib evaluation.
Harvard Health Publications. Special MRI scan could identify stroke risk in people with atrial fibrillation. Howard LeWine, MD. Web. May 13, 2015.
National Stroke Association. What is stroke? Web. May 13, 2015.
National Institute of Neurological disorders and Stroke. NINDS Atrial Fibrillation and Stroke Information Page. Web. May 13, 2015.
Reviewed May 14, 2015
by Michele Blacksberg RN
Edited by Jody Smith