Atrial flutter (AFL) is a type of abnormal heart rhythm, or arrhythmia. It occurs when the upper chambers of your heart beat too fast, causing the bottom chambers to also beat faster than normal.
Atrial flutter impedes your heart’s ability to pump blood effectively throughout your body. If left untreated, AFL can damage your heart muscle and increase your risk of stroke or blood clots.
Atrial flutter is similar to the more common condition atrial fibrillation (AFib), except the rhythm in atrial flutter, the atrial racing tends to be regular, unlike in atrial fibrillation, where an irregular rhythm is more common.
Symptoms of AFL are wide-ranging and can include one or more of the following conditions. Symptoms can last for hours, days, or even weeks at a time.
- a fast and usually steady pulse
- shortness of breath
- lightheadedness or feeling faint
- pressure or tightness in the chest
- heart palpitations
- fatigue that keeps you from doing everyday activities
These symptoms can be similar to those of other heart conditions. They can also be associated with conditions unrelated to the heart.
Having one or more of these symptoms isn’t always a sign of AFL. Also, some people with AFL feel no symptoms at all.
Because of this complexity of pinpointing AFL symptoms, it is always a good idea to discuss any concerns with your doctor.
Researchers do not know for certain what causes atrial flutter. It is thought to result from damage to the heart, its electrical system, or to parts of the body that affect the heart.
A natural pacemaker (the sinus node) controls your heart rate. It’s located in the right atrium. It sends out electrical signals to both the right and left atria. Those signals tell the top of the heart how and when to contract.
When you have AFL, part of the signal from the sinus node travels abnormally fast in a continuous loop around the right atrium.
This makes the upper chamber of the heart beat too quickly at between 250 to 320 beats per minute (bpm), and the lower chambers usually at about 150 bpm (the upper beats conduct in a 2:1 ratio to the bottom chamber).
In contrast, a normal resting heart rate is between 60 to 100 bpm, where the upper and lower chambers are beating at the same rate.
This is the rate at which the lower part of the heart pushes out blood to the rest of the body. It is the rate that you commonly measure when you touch the neck or wrist, or use a medical instrument or smart device.
Researchers have linked many factors to the disruption in the heart’s electrical circuitry that causes AFL. It is sometimes difficult to pinpoint the precise root cause.
However, AFL itself is easily recognizable by its classic sawtooth pattern on an electrocardiogram (ECG). This is a test that shows your heart’s rhythm.
Read on to learn about the various causes that contribute to AFL.
Underlying heart disease or abnormalities are a major cause of AFL. Examples include:
- scarring from previous heart surgery or cardiac ablation, a nonsurgical procedure for treating both AFL and AFib
- decreased blood flow to the heart (ischemia), usually resulting from hardening of the arteries (atherosclerosis) or blood clot.
- high blood pressure
- disease of the heart muscle (cardiomyopathy)
- heart valve disorders
- enlarged heart chamber (hypertrophy or dilation)
- heart incident, such as a heart attack
- blood clot in the lungs
- Non-cardiac surgery
Conditions in other parts of the body that affect the heart can also contribute to the development of AFL. Examples include:
- thyroid disease
- blood clots
- chronic lung diseases, such as chronic obstructive pulmonary disease (COPD) or emphysema
- untreated sleep apnea
Lifestyle factors are also thought to play a part in developing AFL. This often involves ingesting substances that might affect the electrical systems of the heart.
- alcohol misuse
- substance misuse, especially stimulants
- ingesting certain drugs, such as diet pills or cold medications
- consuming high amounts of caffeine
Although risk factors for AFL are wide-reaching, no one risk factor causes AFL. There are many underlying medical conditions, certain medications, and some lifestyle choices that contribute to your risk for AFL.
Any of the following may increase your risk for developing AFL:
- age 50 years or older
- high blood pressure
- coronary heart disease
- congenital heart conditions
- past heart attack
- past heart surgery
- lung disease
- thyroid disease
- chronic stress or anxiety
- certain medications, such as cold medication or diet pills
- misuse of alcohol or other stimulant drugs
- untreated sleep apnea, which may cause dilation of the heart chamber
Doctors start to consider AFL if your heartbeat at rest goes above 120 bpm and if your ECG shows signs of atrial flutter.
Your family history may be important when your doctor is trying to diagnose AFL. A history of heart disease, anxiety, and high blood pressure can all affect your risk.
Your primary care doctor can make a preliminary diagnosis of AFL with an ECG. You may also be referred to a cardiologist for further testing.
Several tests are used to diagnose and confirm AFL:
- Echocardiograms use ultrasound to show images of the heart. They can also measure the flow of blood through your heart and blood vessels and see if the heart has shown any signs of getting weak due to beating fast (tachycardia induced cardiomyopathy) or dilation of the atria (chambers of the heart where AFL originates).
- Electrocardiograms record the electrical patterns of your heart.
- Holter monitors allows a doctor to monitor the heart’s rhythm for at least a 24-hour period.
- Electrophysiology (EP) studies are a more invasive way to record heart rhythm. A catheter is threaded from the veins of your groin into your heart. Electrodes are then inserted to monitor heart rhythm in different areas.
Your doctor’s main goal is to restore your heart rhythm to normal. Treatment depends on how severe your condition is and how you respond to medications.
Underlying health problems can also affect AFL treatment and may need to be treated as well.
Medications can slow or regulate your heart rate. Examples of these medications include:
Certain medications may require a brief hospital stay while your body adjusts, such as anti-arrhythmic medications.
Blood thinners, such as non-vitamin K oral anticoagulants (DOACs), can be used to prevent clot formation in your arteries. Clotting can cause a stroke or heart attack.
People with AFL have an increased risk for blood clots. Whether they are treated with blood thinners depends on their age, sex, and other risk factors, using a scoring system called CHA2DS2-Vasc.
Warfarin has been the traditionally prescribed anticoagulant, but DOACs are now preferred because they don’t need to be monitored with frequent blood tests and they have no known food interactions.
Ablation therapy silences the heart tissue that’s causing the abnormal rhythm.
It is used when AFL can’t be controlled through medication or there are side effects of medications, but it’s increasingly being offered as a first-line treatment for atrial flutter.
Cardioversion uses electricity to shock the heart’s rhythm back to normal as a way to “reset” the heart’s rhythm out of atrial flutter. After anesthesia is given, paddles or patches applied to the chest induce the shock.
Medications can be successful in treating AFL, but more often, physicians will use a cardioversion or ablation procedure to restore normal sinus rhythm.
The condition can sometimes recur after treatment depending on the cause of your AFL. Many physicians are now favoring using ablation at the initial diagnosis of AFL.
You can lower the risk of recurrence by reducing your stress levels and taking your medications as prescribed.