Perhaps you have heard of atrial fibrillation. You’ve seen it in the news or have a friend or relative with it. Or a doctor has just told you that you have it. But what exactly is it?
Atrial fibrillation is a fancy name for an irregular and/or rapid heartbeat. Usually, the heart pumps blood in a seamless kind of coordinated dance, with all four chambers gracefully working together. But this doesn't always happen.
If the left and right atria, the heart's upper chambers, are beating erratically, they become out of sync with the left and right ventricle, the two lower chambers of the heart. This weakens the blood flow to the rest of your body and can lead to shortness of breath and weakness.
While this may happen here and there to some people, it can be chronic in others. The condition itself is unlikely to cause death, but treatment is important because it can lead to complications that are life-threatening, such as blood clots, stroke or heart failure.
Being vigilant about your symptoms can help prevent these more serious complications. Strokes usually result when a clot breaks loose from the heart and travels to the brain, according to Sarah Samaan, MD, a cardiologist with Legacy Heart Center in Dallas-Fort Worth.
These clots can form because "...the erratic rhythm in the atria can allow blood to pool in little 'pockets,' since the atria are quivering, rather than squeezing," she said.
However, this generally happens only when someone has been in atrial fibrillation for more than 24 hours, so seeking medical care within this window allows proper treatment and possible avoidance of a stroke.
What Are the Symptoms?
It is possible to have atrial fibrillation and not know it until a doctor discovers it. But if you do feel symptoms, they will center on the effects of getting insufficient blood flow to your body. These include lightheadedness, shortness of breath, chest pain, weakness and decreased blood pressure.
You may also experience confusion since your brain may not be getting the blood it needs. The clearest symptom is the actual feeling of an irregular heartbeat or an uncomfortably racing heart. If your chest feels like it's flopping around like a struggling fish, it's definitely important to call your doctor. If you experience severe chest pain, you should seek emergency assistant in case it's a heart attack.
Those with occasional or "paroxysmal" atrial fibrillation have intermittent symptoms, but for those with chronic atrial fibrillation, "normal" is an abnormal heart rhythm. While a normal heart rate range is 60 to 100 beats a minute, a heart with atrial fibrillation can go from 100 to 175 beats per minute.
There are a wide range of causes for atrial fibrillation, most commonly leading back to a structural problem in the heart. Though individuals can be born with the condition as a congenital heart defect, this is rare, according to Dr. Samaan. She said most people in the US who develop atrial fibrillation are age 65 and older. "Many of them have high blood pressure, coronary artery disease, heart valve abnormalities or lung disease," she said.
Other possible but less common causes include developing it following heart surgery or a heart attack, a metabolic imbalance (such as thyroid issues), viral infections and sleep apnea. Severe stress from an illness or surgery may also bring on atrial fibrillation, and a condition called sick sinus syndrome, in which your heart's natural pacemaker is out of whack, can cause it.
Atrial fibrillation can also be caused or made worse by stimulants like caffeine, tobacco or stimulant medications. Alcohol can play a part as well. In other less common cases, there is no cause that can be determined.
Those most at risk for developing atrial fibrillation, other than being born with a heart defect, are those with heart disease, high blood pressure, chronic health conditions like sleep apnea or thyroid problems, heavy drinkers and those with a family history of atrial fibrillation. Age is also a risk factor: as you grow older, your risk of developing the condition increases.
How Is Atrial Fibrillation Diagnosed?
There are a variety of tests that help medical professionals determine whether you have atrial fibrillation. Many of these are imaging tests, such as X-rays or ultrasounds, and others involve wearing devices to monitor your heart rate.
An electrocardiogram (EKG) is the most common and easiest way to diagnose atrial fibrillation. An EKG is the machine that attaches electrodes to your skin and measures your heartbeats with the famous bouncing line on a screen that you probably associate with a heart rate.
"However, some people have paroxysmal atrial fibrillation, so a routine EKG may not pick it up," Dr. Samaan said. "In those cases, a heart monitor (from 24 hours or up to 30 days) can usually detect the rhythm abnormality."
A Holter monitor records your heartbeats, but you wear it under your clothing during a few days of ordinary activity instead of being restrained to the lab. Event recorders also are worn under your clothing, but they don't track all your heartbeats. Instead, they transmit signals when you have symptoms (as Holter monitors can do, as well) or they are worn for several weeks to identify changes in the heartbeat that are more random.
If a person has atrial fibrillation symptoms that are more infrequent than once a month, Dr. Samaan recommends being vigilant about your symptoms and then seeking medical attention. "In those cases, it is important to get to a doctor's office or ER when the symptoms start, so that an EKG can be done during the episode," she said.
Doctors may also order chest X-rays or echocardiograms, but these tests are aimed at detecting underlying conditions that could contribute to atrial fibrillation, not diagnosing atrial fibrillation, Dr. Samaan said. An echocardiogram is basically an ultrasound of your heart. Sound waves are bounced off your heart to create an image so that technicians can see how your heart operates.
Treatment for Atrial Fibrillation
Ideally, you can reduce your risk of atrial fibrillation or improve your condition with healthy habits, such as reducing your salt intake, not smoking, being physically active, drinking alcohol moderately (only one to two drinks a day) and eating heart-healthy foods. But often additional treatment is necessary.
The primary goal in treating atrial fibrillation, aside from avoiding serious complications, is to "reset" the heart rate rhythm and to prevent blood clots. Resetting the heart rhythm can be done with "cardioversion" medications called "anti-arrhythmics" or with electrical cardioversion where you receive a small electrical shock while sedated to stop and restart your heartbeat – hopefully with a more consistent beat this time.
Common anti-arrhythmic medications include amiodarone (Cordarone, Pacerone), dronedarone (Multaq), propafenone (Rythmol), sotalol (Betapace), dofetilide (Tikosyn) and flecainide (Tambocor). The most common side effect for these medications include nausea, dizziness or fatigue.
However, Dr. Samaan points out that resetting the rhythm may not always be necessary.
"For some people, slowing down the heart rate with medication (typically beta blockers, calcium channel blockers, or digoxin) rather than converting the rhythm, may be safer and more appropriate, especially for those who have no symptoms with atrial fibrillation when the rate is controlled," Dr. Samaan said. "Like most people with atrial fibrillation, these people usually require treatment with blood thinners to prevent strokes."
The most common medications given to reduce the risk of blood clots are three different blood thinners: warfarin (Coumadin), dabigatran (Pradaxa) and rivaroxaban (Xarelto). When taking these medications, you should avoid activities that make you more prone to injury or bruising, such as contact sports.
There are other options for treatment that can be explored if these medications or electrical cardioversion are not effective, including a different class of medications, a procedure called atrioventricular node ablation.
"The atrioventricular node ablation procedure requires placement of a pacemaker, since the atria and ventricles can no longer communicate electrically after the procedure," Dr. Samaan said. "There is also an 'atrial fibrillation ablation' procedure, which involves trying to locate the electrical spot in the atrium where the atrial fibrillation originates, and 'zapping' it with radio frequency. These procedures are becoming more common as the technology evolves."
While atrial fibrillation can sound like a frightening condition to some, it is a condition that can usually be managed. The important thing is to seek medical attention if you have the symptoms and to follow the treatment plan your doctor designs for you.