Q. What is atrial fibrillation?
Atrial fibrillation is one of the most common abnormal heart rhythms. Normally the heart is stimulated to beat at a regular rate by electrical impulses which are conducted through the heart muscle in a very organized way.
These impulses first pass through the atria, the upper chambers of the heart, causing them to contract in a coordinated fashion and pump blood into the lower chambers of the heart, called ventricles.
The electrical impulses then pass through the ventricles causing them to contract and pump blood to the rest of the body. In atrial fibrillation, however, inappropriate electrical impulses lead to disorganized stimulation of the atrial muscle fibers. This causes them to quiver rapidly rather than contract in an organized way. Atrial fibrillation results in an irregular and sometimes very rapid heart beat which can last anywhere from a few minutes to many years. Atrial fibrillation is common in adults and happens more often as we age.
Q. What are the symptoms of atrial fibrillation?
If your heart is in atrial fibrillation it cannot efficiently pump blood to your body. The symptoms caused by atrial fibrillation can vary greatly from person to person. Many people don’t feel any symptoms at all and aren’t aware that their heart is beating irregularly. Others may notice their heart beating much faster than normal and could become very dizzy or pass out.
Atrial fibrillation can also cause chest pain and shortness of breath. If you check your pulse while your heart is in atrial fibrillation you might notice that the beats don’t occur at regularly spaced intervals.
Q. What are complications of atrial fibrillation?
The main complication of atrial fibrillation is an increased risk of having a stroke. The uncoordinated heart contractions that occur in atrial fibrillation can cause the blood to move more slowly through the heart. This stagnant flow greatly increases the risk of forming a blood clot, which could later leave the heart and cause a stroke. The risk of an individual with atrial fibrillation having a stroke is increased by several factors including age, hypertension, diabetes, other heart conditions, and a history of a previous stroke.
Q. How is atrial fibrillation treated?
Treatments for atrial fibrillation are designed to accomplish two goals. The first goal is to either reestablish a regular heart rhythm or to control the heart’s rate. A heart’s rhythm can be reset by electrically shocking the heart or by the use of medications which change the electrical activity of the heart. If it is not possible to reset the heart’s rhythm, then medications can be used which regulate how fast the heart beats.
The purpose of this treatment is to slow the heart so that it beats at a normal rate of less than 100 beats per minute. Slowing the heart down can often help it to pump blood more efficiently and can reduce the symptoms caused by atrial fibrillation. If medications are not effective, there are some surgical options which can be considered.
The second goal of treatment is to reduce the formation of blood clots which could lead to strokes.
In order to do this, patients with atrial fibrillation are often prescribed medications to thin the blood (anticoagulants) like aspirin or warfarin (coumadin). These medications have been shown to reduce the risk of strokes in patients with atrial fibrillation.