What Is Atrial Fibrillation?

This type of irregular heartbeat affects millions of Americans. Understanding the causes and symptoms of atrial fibrillation can help you manage the condition and prevent additional complications.

By Chris Iliades, MD

Medically reviewed by Lindsey Marcellin, MD, MPH

Atrial fibrillation is a condition that affects millions of Americans. This type of irregular heart rhythm, also known as an arrhythmia, is the most common serious irregular heartbeat, especially in people over 60.

Your heart's rhythm is normally controlled by a structure in the upper part of your heart called the sinoatrial node. This node sends an electrical signal to the rest of your heart that keeps your heart beating at about 60 to 100 beats a minute. This is known as your normal sinus rhythm.

In atrial fibrillation, the sinoatrial node does not direct the heartbeat. Rather, it causes heartbeats to start from many locations in upper chambers of the heart, or the atria. "These irregular heartbeats all over the atria cause the upper part of the heart to quiver like a bag of worms," says Danya L. Dinwoodey, MD, a cardiologist at the Lahey Clinic in Burlington, Mass.

The term atrial fibrillation refers to the quivering, or fibrillation, of the upper parts of the heart. It can cause your heart to beat very quickly and inefficiently, which can be dangerous.

Causes of Atrial Fibrillation

The cause of atrial fibrillation can vary from person to person, and sometimes it’s difficult to determine. In many cases, there is a combination of causes. "The most common causes are high blood pressure or an abnormal heart valve," explains Dr. Dinwoodey.

Other causes of atrial fibrillation include:

Coronary artery disease (the clogging of the arteries of the heart that may cause a heart attack)

Heart failure

Heart defects you are born with

Pericarditis (an infection of the lining of the sac that surrounds the heart)

An overactive thyroid gland

Risk Factors for Atrial Fibrillation

The biggest risk factor for atrial fibrillation is age. The condition occurs more often in people over 60, and the risk for developing it increases as you get older.

Other common risk factors include:

Obesity

Diabetes

Sleep apnea

Lung disease

Family history of atrial fibrillation

Heavy use of alcohol

Symptoms of Atrial Fibrillation

Not everyone who has atrial fibrillation experiences symptoms. “Some people are very aware of their symptoms and can tell right away when an episode of atrial fibrillation starts and stops," Dinwoodey says. “Other people may not notice any symptoms. For people who have symptoms, the most common ones are decreased tolerance for exercise and feeling a flutter in the chest.”

Other symptoms of atrial fibrillation may include:

Shortness of breath

Dizziness

Chest pain

Tiredness

There are two different types of atrial fibrillation, and the frequency of symptoms varies with each type. Paroxysmal atrial fibrillation begins suddenly and often stops on its own. Persistent atrial fibrillation lasts for more than a week, and while it may stop on its own, it frequently requires treatment. Both types may become permanent over time.

If you believe that you are at risk for atrial fibrillation or if you think you’ve experienced an irregular heartbeat, make an appointment to get evaluated by your doctor. Atrial fibrillation can lead to serious problems and additional complications over time. Fortunately, there are many types of treatment that can help keep this condition under control.

Phases of Alzheimer's Disease

Experts have found that most Alzheimer’s patients go through seven stages of disease progression. The duration and symptoms might vary, but the general decline of Alzheimer's remains the same.


1. No Impairment

Individuals at this stage show no marked decline in their cognitive function. No memory problems show up on a regular basis.

2. Very Mild Impairment

Forgetfulness begins. The patient begins to forget names and small details, like where they put their glasses or if they took their medication that morning.

3. Mild Decline

At this point, family and friends begin to notice the symptoms. Losing things is more common, and the patient might begin having performance issues at work.

4. Moderate Decline

The problems are now clear in medical interviews. The patient begins forgetting personal history, recent events, and how to handle complex tasks, such as planning dinner or paying bills. They could begin acting withdrawn or subdued in social situations.

5. Moderately Severe Decline

While the patient may remember their own name and the names of those important to them, they begin to forget basic information, such as the current date, time, or season. Day-to-day tasks like cooking may no longer be safe.

6. Severe Decline

Now, the patient needs more help with basic activities like dressing and using the toilet. They might also experience behavioral changes, such as feeling suspicious or experiencing hallucinations. Someone at this stage might engage in repetitive behaviors or wander away, only to become confused and lost.

7. Very Severe Decline

In this final stage, the patient may lose the ability to speak coherently. They may need help with general hygiene, and may eventually lose muscle coordination and the ability to control movement. Their muscles typically grow rigid, the reflexes become unpredictable, and eventually even swallowing could become impaired.


Caring for a loved one with Alzheimer’s can be exhausting and frustrating, but you don’t have to go it alone. There are many services that can help, such as adult day care and in-home care services.