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Atrial fibrillation, also known as afib, is a term used to describe a disorder of the heart. Atrial fibrillation is a form of cardiac arrhythmia, which means that the heart’s normal beating rhythm is interrupted. The condition may be permanent, may come and go without treatment, or may be stopped only with treatment.
Atrial fibrillation can cause heart palpitations, chest pain, dizziness, shortness of breath, weakness, and fatigue, although many people experience no symptoms at all. It is estimated that approximately two million people in the United States experience atrial fibrillation. While the condition itself is not generally fatal, it can lead to increased risk of stroke, heart failure and heart attack.
Heart disease and high blood pressure are the two main known causes of atrial fibrillation. Both of these conditions can cause damage to the heart, making it more susceptible to cardiac arrhythmia. Other common causes are heart abnormalities or defects, illness, sleep apnea, and metabolic or chemical imbalances in the body.
The heart is composed of four chambers. The top two chambers are known as the atria and the bottom two chambers are known as the ventricles. All of the chambers must contract or expand at precisely the right time to ensure that blood is received from the body, oxygenated and then pumped back out to the body effectively.
After the body has depleted the oxygen in the blood, it enters the heart through the right atria. From the right atria the blood is pumped to the right ventricle, where it is pumped to the lungs, which replenishes the blood with oxygen. Once replenished with oxygen, the blood is transported from the lungs to the left atria, where it is pumped into the left ventricle. From the left ventricle, the oxygen-rich blood flows into the aorta, which is the largest artery in the body. From the aorta, blood reenters the bloodstream and is distributed throughout the body.
In a healthy heart, regular electrical impulses tell the heart when to expand and contract. During atrial fibrillation, the electrical impulses are irregular and very rapid. This causes the left and right atria to quiver instead of beating effectively. As a result of the irregular heartbeat, the atria may not fully pump out all of the blood that is in it, possibly causing blood to pool and collect.
When blood is allowed to collect, clots are more likely to form. If a piece of a formed blood clot breaks away and flows out of the heart, it may lodge in an artery of the brain causing a stoppage of blood flow to the brain, resulting in a stroke. It has been estimated that approximately 15% of patients who experienced a stroke also experienced atrial fibrillation.
Treatment of atrial fibrillation generally consists of preventing blood clots from forming and restoring regular rhythm to the heart. Blood thinning and anti-clotting medication is often prescribed to reduce the risk of a stroke. Medication can also help regulate the rhythm and rate of the heart. In addition to medication, treatment may also consist of surgical and non-surgical procedures to restore normal rhythm to the heart.