What Is Atrial Fibrillation?
Atrial fibrillation (AFib) is a condition that disrupts the body's regular
heartbeat. A glitch in the heart’s electrical system makes the upper chambers
(the atria) quiver. This causes the lower chambers (the ventricles) to beat
irregularly. AFib can be dangerous because it raises the risk of stroke and
heart failure.
Warning Sign: Uneven Pulse
In many people, AFib does not cause obvious warning signs.
When symptoms do
occur, they often include:
- An uneven pulse
- A racing or pounding
heart
- A feeling that the heart is
fluttering
- Chest pain
Normal Heart Rhythm vs. AFib
Electrical signals between the atria and ventricles help the heart pump
blood in steady rhythm. In AFib, the atria fire abnormal signals, which
make the top chambers quiver rapidly. The result can be irregular contractions
that can cause a fast, irregular heart rate (100-175 beats per minute). The
normal range is 60-100 beats per minute.
Warning Sign: Dizziness
An irregular heartbeat can take a toll on the body, leading to problems such
as:
- Dizziness
- Breathlessness
- Weakness and fatigue
- Fainting
AFib and Stroke
If the heart isn’t pumping like it should, blood can pool and may form a
clot. This clot can travel through the bloodstream to the brain, causing a
stroke. People with AFib are five times more likely to have a stroke than those
without it.
When to Seek Emergency Care
AFib is not always an emergency, but you should call 911 if you have any of
these symptoms:
- Severe chest pain
- Uneven pulse and feeling
faint
- Signs of a stroke, such as
numbness or slurred speech
What Causes AFib?
The most common triggers are conditions that strain the heart, including:
- High blood pressure
- Coronary artery disease and
heart attacks
- Heart failure
- Problems with the heart
valves
In some cases, AFib may come from thyroid disorders or serious infections
like pneumonia.
Risk Factors You Can't Control
Besides heart conditions, there are several factors that raise your risk of
developing AFib. Some of these are outside of your control:
- Being male and white
- Being over age 60
- A family history of AFib
Risk Factors You Can Control
Your lifestyle and habits can also raise your risk. AFib has been linked to:
- Obesity
- Lung disease
- Certain prescription drugs
like albuterol
- Stimulants, including some
illegal drugs, and heavy use of nicotine
- Drinking too much alcohol
Heart Surgery Can Be a Trigger
Having a coronary artery bypass or other type of heart surgery can trigger
AFib. When AFib happens after surgery, it increases the risk of other
complications. The good news is this type of AFib is usually short-lived.
Lone AFib
Sometimes AFib happens without an obvious trigger. This is called lone AFib,
and it’s more common in people younger than 65. You may need treatment if
a rapid heartbeat causes troubling symptoms. Doctors may recommend treating
lone AFib to reduce the risk of stroke in certain people.
Diagnosing AFib: EKG
The surest way to detect AFib is with an electrocardiogram (EKG). This
painless test records the electrical activity of your heart and reveals
problems with the heart’s rhythm. You can take the test in a doctor’s office,
or your doctor may ask you to wear a device that records your heart’s activity
continuously for 24 hours or more.
Other Tests for AFib
If an EKG shows that you have AFib, your doctor may order other tests to
learn more about your heart. An echocardiogram or ultrasound of the heart can
show whether there is any valve damage or signs of heart failure. A stress test
can show how well your heart is performing. Your doctor may also order tests to
look for conditions that may have triggered your AFib.
The Course of AFib
When people first develop AFib, it may come and go. The irregular heart
rhythm may last anywhere from a few seconds to a few weeks before returning to
normal. In some people, the heart rhythm can remain irregular. If the
trigger is a thyroid problem, pneumonia, or other treatable illness, AFib
usually goes away once the cause is treated.
Treatment: Cardioversion
In some cases, your doctor may try to restore a normal heart rhythm with an
electrical shock or medication. This is known as cardioversion. If you’ve been
having AFib for more than 48 hours, cardioversion could raise your risk of
stroke. In that case, you may need to take a blood thinner for several weeks
before your doctor tries it, as well as after cardioversion.
Treatment: Medication
If your symptoms are mild, or if AFib comes back after cardioversion, you
may be able to control it with medicine. Rhythm-control medicines help regulate
your heart rhythm. Rate-control medicines keep your heart from beating too
fast. Daily aspirin or anti-clotting medicines such as dabigatran, rivaroxaban,
or warfarin can help reduce the risk of stroke in certain people with
AFib.
Treatment: Ablation
If cardioversion and medications can't control the symptoms of AFib,
radiofrequency ablation may help. This procedure uses radiofrequency energy to
destroy the heart tissue that sends out faulty electrical signals. Although it
does not require open heart surgery, ablation has some risks. It is only
recommended for people who have serious symptoms despite trying other
treatments.
Treatment: Surgery
A type of surgery called the maze procedure can cure AFib. Doctors make a
pattern of small cuts to create scar tissue in the atria. The scar tissue
blocks the abnormal signals that cause AFib. Doctors usually do this procedure
during open heart surgery, but some medical centers are now offering a
minimally invasive procedure.
Treatment: Pacemaker
A pacemaker is a small, battery-powered device that regulates your heart
rate by firing off electrical signals. For example, it can be helpful for
people who have a very slow heart rate. It can relieve symptoms such as fatigue
and shortness of breath. A pacemaker is also required after certain types of
ablation. Implanting a pacemaker in the chest is considered minor surgery and
usually takes about an hour.
AFib: Outlook
Many people find that AFib has no impact on their daily lives. Others must
try different treatments to manage troubling symptoms like weakness, shortness
of breath, or fainting. In either case, it’s important that people with AFib
take steps to reduce the risk of stroke.
Preventing AFib
The same healthy habits that protect against heart disease will protect
against AFib:
- Eat a nutritious diet that
includes fish.
- Exercise regularly.
- Control your blood pressure.
- Avoid smoking.
Check Your Pulse Regularly
AFib can lead to a stroke or other serious problem before it causes
noticeable symptoms. To catch an irregular heartbeat early, the National Stroke
Association recommends checking your pulse once a month -- especially if you
are over 40 or have risk factors for stroke. If the rhythm seems unsteady or
you have any concerns, contact your health care professional.