A reentry arrhythmia is an abnormality in your heart’s rhythm in which electrical impulses in your heart stray from their usual path and form a closed-loop circuit. Treatment can usually resolve these types of arrhythmias.

The electrical impulses that keep your heart beating in a steady, consistent rhythm follow the same path throughout the heart dozens of times per minute. A disruption in that pattern is called an arrhythmia. Arrhythmias can cause the heart to beat abnormally fast or slow or in a chaotic, irregular manner.

A reentry arrhythmia is one in which electrical impulses stray from their usual path and repeatedly return to the tissue that generated them, essentially forming a closed-loop circuit. When a closed-loop circuit interrupts the normal flow of electrical impulses in the heart, troubling symptoms and health complications can follow.

There are several different types of reentry arrhythmias, some of which can lead to severe cardiac complications.

It’s often possible to treat a reentry arrhythmia with medications and procedures that block the circuit and restore healthy electrical activity in the heart.

This article reviews the different types of reentry arrhythmia, their symptoms, causes, treatment, and outlook.

The normal pattern of electrical activity in your heart begins with the sinus node generating an electrical stimulus. The sinus node is located near the top of the heart in the right atria.

The sinus node causes the atria to contract and pump blood down to the lower chambers (ventricles). The electrical impulses also move down to the atrioventricular node located between the atria and ventricles.

The impulses pause, and then spread out in electrical pathways known as the bundle of His. Bundle branch ways then carry electrical impulses to stimulate the ventricles, causing them to pump blood out to your lungs and the rest of your body.

A reentry arrhythmia occurs when at least some of the impulses constantly traveling through your heart’s electrical network don’t pause and move on as they should, but instead loop back around and stimulate the atria or ventricles again and again.

A heart can be in a state of reentry arrhythmia for very brief or extended episodes. The main cause of a reentry arrhythmia is the presence of an extra electrical pathway, called a reentrant circuit, that keeps impulses moving in a circle, re-exciting tissue instead of letting it rest in between contractions.

The location of the reentry circuit determines what type of reentry arrhythmia develops. Some of the more common examples include:

AVNRT is the most common type of reentrant supraventricular tachycardia, and it can lead to a sustained heart rate of more than 100 beats per minute.

AVNRT episodes can come and go, though they tend to be initiated by physical exertion.

Several conditions can create reentry circuits that then lead to reentry arrhythmias. Some people are born with an extra pathway, though the arrhythmia may not develop until later in life.

Other individuals born with unrelated congenital heart defects may develop a reentry circuit following surgery to repair a different structural problem within the heart.

Scar tissue that results from any type of heart surgery has the potential to become a new pathway for electrical impulses. Similarly, scar tissue that forms after tissue is damaged during a heart attack can also become a reentry circuit.

Abnormalities involving electrolytes, such as sodium and potassium, can cause structural changes in the heart that become reentry circuits.

Certain gene mutations are also associated with reentry arrhythmias. These mutations affect the nature of electrical pathways in the heart, making them more likely to become circuits.

A 2020 study suggests that mutations of genes such as SCN1A, PRKAG2, RYR2, CFTR, NOS1, PIK3CB, GAD2, and HIP1R may affect pathways that produce AVNRT.

In very mild cases of reentry arrhythmia, you may not notice any symptoms. The arrhythmia might be detected in an unrelated medical exam that includes an electrocardiogram (EKG) that measures the heart’s electrical activity.

When noticeable symptoms are present, they can include:

  • chest pain, pressure, or discomfort
  • fatigue
  • heart palpitations or the feeling that your heart is skipping beats
  • lightheadedness or dizziness
  • rapid or racing heartbeat
  • sweating

While an especially rapid heartbeat is normal after a workout or some physical exertion, your heart rate should soon return to normal with rest. With an arrhythmia, an abnormally fast heart rate may come on with no reason or it may not subside with rest after physical activity.

When to seek immediate medical attention

If you experience chest pain or pressure or shortness of breath (without physical exertion) seek immediate medical attention. These can be symptoms of a heart attack.

Likewise, if you feel as though you’re going to faint, call or have someone near you call 911 or local emergency services. These symptoms may not be medical emergencies, but it’s always important to take them seriously.

Was this helpful?

Reentry arrhythmias cause the heart to work less efficiently. They can overwork the heart, and over time, this can weaken the heart muscle and lead to heart failure.

Some arrhythmias can lower the volume of blood being pumped out of your heart. Initially, this can cause feelings of lightheadedness as less blood is circulating through the brain, but ultimately this can affect the health and function of all your organs.

Reentry arrhythmias affecting the atria, such as AFib or atrial flutter, are associated with higher risks of blood clot formation that can lead to stroke.

Ventricular arrhythmias tend to be much more dangerous and can result in cardiac arrest or even cardiac death.

The type and location of a reentry arrhythmia determine how it will be treated.

  • Blood thinners: AFib, whether persistent or intermittent, should be treated with anticoagulant medications (blood thinners) based on the CHA2DS2-VASc score. Blood thinners lower the risk of clotting and stroke.
  • Vagal maneuvers: Someone with supraventricular tachycardia (abnormally rapid heart rate originating just above the ventricles) may be taught vagal maneuvers, which slow down the heartbeats and help the heart resume its normal electrical flow.
  • Ablation: Typically, the goal of reentry arrhythmia treatment is to end the reentry circuit to restore consistent and healthy electrical activity throughout the heart. This is often done with a procedure called catheter ablation, which delivers radiofrequency energy or cold energy (cryoablation) to destroy a small amount of tissue.
  • Antiarrhythmics: Some reentry arrhythmias may be treated with antiarrhythmic drugs, such as adenosine. A 2020 study suggests that adenosine, which has been used for decades to treat various types of tachycardia, can be helpful in revealing incomplete ablation procedures.
  • Cardioversion: Cardioversion therapy is the application of electrical impulses delivered from outside the chest, which can sometimes “shock” a heart back into a normal, healthy rhythm.

Regardless of which treatment, or treatments, are used, someone with a reentry arrhythmia should try to adopt a heart-healthy lifestyle. This means regular exercise, as recommended by a medical care team, and a balanced diet, low in sodium and processed foods.

With treatment, reentry arrhythmias can often be ended, allowing you to live a long and healthy life. Radiofrequency ablation, for example, is successful in ending reentry circuits in about 97% of people with AVRT.

Sometimes multiple procedures may be necessary to completely eliminate the arrhythmia. When a reentry arrhythmia can’t be cured or eliminated, you’ll need to work closely with a cardiologist to track and manage your heart health.

Difficult-to-treat arrhythmias may require the help of an electrophysiologist, a cardiologist who specializes in arrhythmias.

A reentry arrhythmia is a heart rhythm disturbance triggered by an electrical impulse that follows an additional pathway instead of the usual path. This abnormal pathway creates a closed circuit to form within your heart. In this circuit, electrical impulses repeatedly stimulate certain chambers without allowing them their usual rest in between heartbeats.

Mild cases may not be problematic, but more serious arrhythmias can lead to unpredictable jumps in your heart rate and other symptoms.

To effectively treat a reentry arrhythmia, you may need a combination of medications and procedures, as well as a commitment to a heart-healthy lifestyle.