Prevent a Stroke, Learn About Atrial Fibrillation

By Douglas Gibson, MD, Scripps Health

According to the National Institute of Health, most adults have an average heart rate of 60 to 100 beats per minute. Most of the time, you don’t think about how fast your heart is beating unless you’re exercising, feeling stressed -- or have cardiac arrhythmia.

Cardiac arrhythmia is a condition in which the heart may suddenly start to beat too quickly, too slowly, or with an erratic rhythm. In serious cases, arrhythmias may increase the risk of heart problems and require treatment.

The most common type of arrhythmia is atrial fibrillation.

Normally, the two upper chambers of the heart (the atria) contract, followed by the two lower chambers (the ventricles), in a steady rhythm. With atrial fibrillation (AFib), the electrical impulses that control this rhythm become irregular, disrupting the atria’s ability to effectively pump blood from the heart. As a result, the heart may beat very quickly, sometimes exceeding 200 beats per minute. In addition to a rapid heartbeat, some people with AFib experience symptoms including shortness of breath, fatigue, dizziness or chest discomfort.

AFib can increase the risk of stroke.

About 30 percent of all strokes in the United States are related to atrial fibrillation. Since AFib prevents the heart from pumping blood effectively, blood can pool in the atria and form clots; in people with AFib, clots are most likely to occur in an area of the left atrium called the left atrial appendage. If these blood clots travel to the brain, they can cause a stroke. People with AFib have a stroke risk that is about 6 times higher than normal and related to AFib tend to be more disabling than other strokes.

Medication can help reduce the risk of stroke, but may have side effects.

Medications such as Warfarin, Eliquis, Xarelto and Pradaxa can help people with AFib reduce their risk of having a stroke, by causing the blood to become thinner, thereby reducing the likelihood of clot formation. While these medications can be very effective, some people find them difficult to use or experience unwanted side effects. Warfarin, for example, requires certain dietary restrictions as well as frequent blood tests to see how thin the blood is and whether the dosage needs to be adjusted. Blood thinning medications can cause some people to bruise more easily, as well as raise the risk of life-threatening bleeding.

Minimally invasive surgical procedures can reduce stroke risk without medication.

Two relatively new, minimally invasive surgical treatments, known as left atrial appendage occlusion procedures, may be options for people who cannot or prefer not to take blood-thinning medications. Both occlude the left atrial appendage, which is where most clots form; this has no effect on normal heart function in adults.

One procedure implants a tiny, parachute-like device called the Watchman into the heart. During this relatively short procedure performed under general anesthesia, the surgeon inserts a long tube called a catheter through a small incision in the groin and threads it through a vein up to the heart. The device is then placed in the heart through the catheter. Most patients spend one night in the hospital and can usually stop taking their blood-thinning medications 45 days after the procedure.

Scripps participated in the research trials that led to FDA approval for the Watchman, and is currently researching a second procedure uses a device called the LARIAT, which ligates or “ties off” the left atrial appendage. It also is minimally invasive and performed under general anesthesia. Early results of the research are promising.

Douglas Gibson, M.D., is an electrophysiologist with Scripps. “To Your Health” is brought to you by the physicians and staff of Scripps. For more information about Scripps, please visit www.scripps.org/Patch or call (858) 914-4275. Join Dr. Gibson for a discussion of how new treatments for atrial fibrillation can help reduce your risk of stroke and other problems related to an irregular heartbeat on Thursday, September 24 from 6–7 p.m. at the Rancho Bernardo Inn. Parking is free and refreshments will be provided. These special events are free, but space is limited. Please call 1-800-SCRIPPS (727-4777) by Monday, September 21, 2015, to register.