What Is Atrial Fibrillation?
Atrial fibrillation (AFib) is a heart rhythm abnormality caused by a problem with the heart's electrical system. Normally, the heart's electricity flows from the top chambers (atria) to the bottom chambers (ventricles), causing the normal contraction. In atrial fibrillation the electrical flow is chaotic causing the heartbeat to become irregular.
Warning Sign: Uneven Pulse
Atrial fibrillation causes an irregular heart rate. If you check your pulse, you will often feel a "fluttering." When atrial fibrillation is new in onset or poorly controlled by medications you will often feel your heart racing. This rapid, abnormal heart rate can be dangerous if not treated and controlled quickly.
AFib vs. Normal Heart Rhythm
When the heart beats with a normal rhythm, electricity flows from the top of the heart to the bottom of the heart, causing the heart muscle to contract and moving the blood through the body. In AFib, the electricity flows chaotically and the bottom chambers of the heart contract irregularly.
Warning Sign: Dizziness
If your heart goes into atrial fibrillation you may experience dangerous and frightening symptoms. AFib may cause symptoms such as:
- Feeling of palpitations
- Shortness of breath
- Chest pain
- Fatigue or exercise intolerance
AFib and Stroke
Atrial fibrillation is a risk factor for stroke. About 15 percent of all people who have strokes have AFib. Because of the irregular and chaotic flow of blood through the heart, small blood clots can form in the heart chambers when you have atrial fibrillation. These clots can travel through the bloodstream to the brain, causing a stroke. This is why people with chronic AFib are usually on blood-thinning medications.
When To Call 911
If you think you are experiencing atrial fibrillation and have chest pain, feel faint, feel a very rapid heart rate (greater than 100 beats per minute), or have any signs or symptoms of a stroke, call 9-1-1 immediately.
What Causes Atrial Fibrillation?
Atrial fibrillation is a common problem. Risk factors for AFib include:
- Poorly controlled high blood pressure (hypertension)
- Heart valve problems
- Coronary artery disease
- Alcohol abuse
- Sleep apnea
- Thyroid disorders
Risk Factors You Can't Control
Having a family history of atrial fibrillation is a strong risk factor for you developing it as well. Your risk of getting AFib also increases with age, and white males have a higher incidence of atrial fibrillation.
Risk Factors You Can Control
There are some risk factors for atrial fibrillation that are in your control. Maintain a healthy lifestyle and watch your weight. Stop smoking and limit alcohol use. Do not use illegal drugs and be very careful if you use certain prescription drugs such as albuterol or other stimulants. Talk to your doctor if you are prescribed these medications and have concerns.
Heart Surgery Can Be a Trigger
One of the risks of having open-heart surgery or coronary artery bypass graft surgery (CABG) is atrial fibrillation. Your doctor will work to control or correct this as it can lead to other complications.
Atrial fibrillation that happens in younger people (less than 60 years old), without an obvious cause is called lone AFib. Lone AFib can be triggered by exercise, eating, sleeping, and alcohol. Sometimes it comes and goes on its own and may not need immediate treatment. Consult your doctor.
Diagnosing AFib: EKG
Your doctor will diagnose atrial fibrillation on an electrocardiogram (EKG). This heart tracing shows a distinct pattern in the electricity of the heart that your doctor can diagnose. If your AFib comes and goes you may need to wear a continuous heart monitor (Holter monitor) to diagnose the abnormal rhythm.
Other Tests for AFib
Once atrial fibrillation is confirmed or suspected your doctor will perform further tests to check your heart muscle and heart valves and to screen for blood clots. These tests include an echocardiogram (ultrasound of the heart) or a stress test or possibly even a catheterization to check the blood vessels for blockage.
The Course of AFib
Atrial fibrillation can come and go on its own or last the rest of your lifetime. When AFib comes and goes within a few minutes to a few hours it is considered paroxysmal AFib. The irregular rhythm from atrial fibrillation may begin to last longer and longer or cause worsening symptoms at which point it will need to be treated and controlled.
In some cases, atrial fibrillation can be corrected with an electric shock to the heart called a cardioversion. In severe emergency cases this may be the only choice to control the AFib. Medications may also be tried to do the cardioversion of your heart rhythm. If your AFib has been going on for more than 48 hours, you may not be a candidate for cardioversion as your risk of having blood clots that could lead to stroke is increased.
Patients with atrial fibrillation are usually prescribed a combination of medicines to prevent complications. Blood thinners or anti-clotting medications help prevent the risk of stroke. Medications that control the rate that your heart beats keep the heart from beating too fast. Some medications are specifically designed to control the electrical rhythm of the heart, keeping it from becoming more irregular and chaotic.
In certain instances, medications or cardioversion may not control your atrial fibrillation effectively. A specially trained cardiologist (called an electrophysiologist) may perform a surgical procedure called an ablation to fix your atrial fibrillation. A radiofrequency ablation is done through a catheter threaded into your heart to send low-voltage, high-frequency electricity into the area of your heart that is causing the irregular electrical rhythm. This destroys the small amount of tissue causing the abnormal heart beat and may totally cure the AFib.
In some cases, surgery on your heart may be needed to treat your AFib. The Maze procedure is a type of surgery where small cuts are placed in the upper chamber of the heart (atria) to help the conduction of electricity to be regular. This procedure may also be done through small incisions or catheters threaded into the heart.
In rare instances, after an ablation to treat your atrial fibrillation your doctor may need to implant a pacemaker. Pacemakers themselves are not designed to treat atrial fibrillation. They are mainly used to correct slow heartbeats. Discuss the possible outcomes of your heart treatment with your cardiologist.
Outlook for AFib
If your atrial fibrillation is well controlled, or corrected with a heart procedure, you may not have any life-changing symptoms from your AFib. Some people with chronic AFib need to be maintained on medications and blood thinners for the rest of their lives. The side effects of these medications can cause long-term complications. Discuss your medications with your cardiologist to see what limitations they may cause on your lifestyle.
Keeping yourself healthy and changing bad lifestyle habits is an important way to lower your risk for atrial fibrillation. Exercise regularly, quit smoking, keep your blood pressure under control, and eat a nutritious diet that is low in fat and salt to lower your risks of heart problems.
Check Your Pulse Regularly
The National Stroke Association suggests everyone over the age of 40 checks their pulse once every month. There is an initiative called "Check Your Pulse" aimed at identifying abnormal heart rates and patients with undiagnosed atrial fibrillation early.