Atrial flutter (AFL) is a common abnormal heart rhythm, similar to atrial fibrillation, the most common abnormal heart rhythm. Both conditions are types of supraventricular (above the ventricles) tachycardia (rapid heart beat). In AFL, the upper chambers (atria) of the heart beat too fast, which results in atrial muscle contractions that are faster than and out of sync with the lower chambers (ventricles).
What is Atrial Flutter?
The electrical system of the heart is the power source that makes the heart beat. Electrical impulses travel along a pathway in the heart and make the upper and lower chambers of the heart (atria and the ventricles) work together to pump blood through the heart.
A normal heartbeat begins as a single electrical impulse that comes from the sinoatrial (SA) node, a small bundle of tissue located in the right atrium. The impulse sends out an electrical pulse that causes the atria to contract (squeeze) and move blood into the lower ventricles. The electrical current passes through the atrioventricular (AV) node (the electrical bridge between the upper and lower chambers of the heart), causing the ventricles to squeeze and release in a steady, rhythmic sequence. As the chambers squeeze and release, they draw blood into the heart and push it back out to the rest of the body and lungs. This is what causes the pulse we feel on our wrist or neck. With AFL, the electrical signal travels along a pathway within the right atrium. It moves in an organized abnormal circular motion, or "circuit," causing the atria to beat faster than the ventricles of your heart. AFL is a heart rhythm disorder that is similar to the more common AFib. In AFib, the heart beats fast and in no regular pattern or rhythm. With AFL, the heart beats abnormally fast, but in a regular pattern. The fast, but regular pattern of AFL is what makes it special. AFL makes a very distinct "sawtooth" pattern on an electrocardiogram (ECG), a test used to diagnose abnormal heart rhythms.
Risk Factors for Atrial Flutter
Some medical conditions increase the risk for developing AFL. These medical conditions include:
- Heart failure
- Previous heart attack
- Acquired or congenital valve abnormalities
- High blood pressure
- Recent upper chamber surgery
- Thyroid dysfunction
- Alcoholism (especially binge drinking)
- Chronic lung disease
- Acute (serious) illness
Symptoms of Atrial Flutter
The electrical signal that causes AFL circulates in an organized, predictable pattern. This means that people with AFL usually continue to have a steady heartbeat, even though it is faster than normal. It is possible that people with AFL may feel no symptoms at all. Others do experience symptoms, which may include:
- Heart palpitations (feeling like your heart is racing, pounding, or fluttering)
- Fast, steady pulse
- Shortness of breath
- Trouble with everyday exercises or activities
- Pain, pressure, tightness, or discomfort in your chest
- Dizziness, lightheadedness, or fainting
Questions to ask your doctor
- What is the cause of my AFL?
- How can I be sure I have AFL and not a more serious heart rhythm problem?
- Will my condition resolve on its own?
- What are the risks that it will become worse (more symptomatic)?
- Am I at increased risk for having a stroke?
- What are my treatment options?
- What are the risks and side effects of medications to control my condition, or to reduce the risk of stroke?
- What are the risks and benefits of other treatment options?
- Should I see an electrophysiologist (a specialist in heart rhythm disorders)?
Complications of Atrial Flutter
AFL itself is not life threatening. If left untreated, the side effects of AFL can be potentially life threatening. AFL makes it harder for the heart to pump blood effectively. With the blood moving more slowly, it is more likely to form clots. If the clot is pumped out of the heart, it could travel to the brain and lead to a stroke or heart attack. Without treatment, AFL can also cause a fast pulse rate for long periods of time. This means that the ventricles are beating too fast. When the ventricles beat too fast for long periods of time, the heart muscle can become weak and tired. This condition is called cardiomyopathy. This can lead to heart failure and long-term disability. Without treatment, AFL can also cause another type of arrhythmia called atrial fibrillation. Atrial fibrillation (AFib) is the most common type of abnormal heart rhythm.