Atrial fibrillation is the most common cause of irregular heartbeat in adults. AFib is caused by abnormal electrical impulses in a part of the heart known as the atria. In time, it can lead to heart failure.

What is AFib?

Atrial fibrillation, or AFib, is the most common type of arrhythmia in adults.

A heart arrhythmia is when your heartbeat has an abnormal rate or rhythm. This can mean it beats too slowly, too quickly, or irregularly.

Arrhythmias are often harmless and may not cause symptoms or complications. However, some types can have serious consequences and require treatment. Dangerous arrhythmias may lead to heart failure, heart attack, stroke, or low blood flow that results in organ damage. Most people with arrhythmias, even the ones that require treatment, live normal and healthy lives.

Approximately 2 percent of Americans under the age of 65 have either intermittent or permanent AFib. In people over the age of 65, the incidence rises to about 9 percent.

AFib is caused by abnormal electrical impulses in the atria, which are the upper chambers of the heart. These chambers fibrillate, or quiver, rapidly. The result is a rapid and irregular pumping of blood through the heart.

In some cases of AFib, the fibrillation of the atria causes the ventricles, or lower chambers of the heart, to beat too fast. This is called a rapid ventricular rate or response (RVR). If you have AFib with RVR you’ll experience symptoms, typically a rapid or fluttering heartbeat. You can also experience chest pain, shortness of breath, dizziness, or passing out. RVR can be detected and confirmed by your doctor. It can cause serious complications and requires treatment.

When the ventricles beat too rapidly they don’t fill completely with blood from the atria. As a result, they can’t efficiently pump blood out to meet the needs of the body. This can ultimately lead to heart failure.

Heart failure as a result of AFib with RVR is most common in those who already have another type of heart disease. RVR can cause chest pain and make conditions such as congestive heart failure worse.

It’s possible to have AFib without RVR. If you have AFib, but a normal ventricular response, you may not experience any symptoms. Some symptoms are possible if you have AFib without RVR. These can include shortness of breath, dizziness, fatigue, or instances of excessive sweating.

The only way to definitively diagnose AFib, as well as RVR, is to get an electrocardiogram (EKG). This is a diagnostic tool that records the electrical activity of your heart. AFib and RVR create distinctive patterns of electrical waves on an EKG that doctors can use to confirm the presence of the arrhythmia.

An EKG can be performed in a doctor’s office, but a 24-hour recording of the heart can also be made using a Holter monitor. This gives a more complete picture of what the heart is doing. Heart monitors may be worn for more extended periods as well.

Learn more: 24-hour Holter monitoring »

Some people with AFib don’t need treatment for their arrhythmia. But the presence of RVR or other health conditions makes the arrhythmia more serious. In these instances, treatment is necessary.

There are three goals of treating AFib with RVR:

  • Control the RVR.
  • Reduce the risk of blood clots.
  • Control the symptoms of AFib.

Medications are typically the first step toward controlling the ventricular rate. Some common medications used to slow the ventricular rate in people with this condition include:

  • beta-blockers such as propranolol
  • calcium channel blockers such as diltiazem
  • digoxin

For some people, medications may fail to restore a normal ventricular rate. In this case, an artificial pacemaker can be installed. This electronic device regulates the beating of the heart. Another option can also include ablation. This is a procedure done by a specialist that eliminates the abnormal electrical pathway that’s causing the arrhythmia.

A normal lifestyle is possible for most people with AFib, even those with RVR. Controlling the heart rate is necessary to maintain good blood and oxygen flow to the heart, brain, and body.

Treatments for AFib with RVR are usually successful, but the condition can return. Talk to your doctor to learn more about the prognosis for your specific condition.