Junctional Rhythm

What is a junctional rhythm?

A junctional rhythm is a type of arrhythmia (irregular heartbeat). If you have a junctional rhythm, your heart’s natural pacemaker, known as your sinoatrial (SA) node, isn’t working as it should.

Your SA node sends electrical signals that control your heartbeat. When you have a junctional rhythm, your SA node stops working or sends signals that are too slow or weak. Your heart responds by using one of your backup pacemakers instead. Your heart’s backup pacemakers keep your heart beating, but they might make your heartbeat slower or faster than normal.

Your heart has three pacemakers that send electrical impulses through your heart. These pacemakers normally work together every time your heart pumps, and they include your:

• SA node: This group of cells usually serves as your first-line pacemaker. Your SA node is in your heart’s upper right chamber (right atrium).
• AV node: These cells often take over if your SA node isn’t working correctly. Your AV node is in the junction, or center, of your heart, between your atria and ventricles. Most junctional rhythms happen in the AV node.
• His-Purkinje system: This group of string-like fibers is also near the middle of your heart. The His-Purkinje system includes the bundle of His and the Purkinje cells. These thin fibers conduct electricity in the heart and serve as a backup pacemaker.

What are the types of junctional rhythms?

All types of junctional rhythms occur when the SA node isn’t working correctly. But there are different ways your heartbeat may change when this happens.

A normal adult heartbeat is 60 to 100 beats per minute (BPM). Junctional rhythm can cause your heartbeat to be slower than normal (bradycardia), or faster than normal (tachycardia). Types of junctional rhythm include:

• Junctional bradycardia: Less than 40 BPM.
• Junctional escape rhythm: 40 to 60 BPM.
• Accelerated junctional rhythm: 60 to 100 BPM.
• Junctional tachycardia: Over 100 BPM.

How common is a junctional rhythm?

A junctional rhythm is less common than other arrhythmias like atrial fibrillation. It is often found in children or adults who have:

• Had a recent heart transplant or heart surgery.
• Sinus node dysfunction, also known as sick sinus syndrome.

How does this condition affect my body?

During a normal heartbeat, your SA node sends a signal to the AV node, which travels to your bundle of His. This series of electrical signals causes all four chambers of your heart to contract (squeeze). As your whole heart contracts, it pumps blood out to your body.

When you have a junctional rhythm:

1. Your atria (upper two chambers of the heart) don’t get the electrical signals from your SA node. These signals are what make your atria contract.
2. Your backup pacemakers produce an electrical signal, but it often only reaches the ventricles (lower chambers of your heart).
3. Your ventricles do all the contracting and pumping, but they can’t pump as much blood on their own. They are dependent on the contraction of the atria to help fill them up so they can pump a larger amount of blood.

With only half of your heart contracting, your organs and tissues don’t get as much oxygen-rich blood. In mild cases of junctional rhythm, you may not feel any different. But in more severe cases, you may have symptoms like shortness of breath or fatigue.

A junctional rhythm usually isn’t life-threatening, but if you have symptoms that interfere with your daily life, you may need treatment.

What are the symptoms of a junctional rhythm?

If you have a junctional rhythm, you may not have any signs or symptoms. But some people with a junctional rhythm experience:

• Anxiety.
• Chest pain.
• Dizziness.
• Fainting.
• Feeling fatigued or weak.
• Heart palpitations (feeling a fast, fluttering or pounding heartbeat in your chest).
• Shortness of breath.
• Slow heart rate.

What are the most common causes of a junctional rhythm?

Causes of a junctional rhythm include:

• Inflammation of the heart: If your heart muscle is inflamed, the SA node may become damaged or stop working. Heart surgery and myocarditis are common causes of heart inflammation. It can also occur from sepsis or certain infections like Lyme disease or rheumatic fever.
• Low oxygen levels: Certain heart problems like myocardial ischemia can lead to low oxygen levels and reduced blood flow in your heart. With lower blood flow in your heart, your SA node may stop working.
• Medications: Certain medicines that treat heart problems or high blood pressure can slow your heart rate and cause a junctional rhythm. However, don’t stop taking any of your medications without talking to your provider first. If you notice side effects from your medications, your provider may prescribe a different dose or type of medication.

How is a junctional rhythm diagnosed?

Your healthcare provider will ask you about your symptoms and do a physical examination. They may also check your vital signs, which include your blood pressure, heart rate and breathing rate. During your exam, tell your provider about your:

• Health history.
• Lifestyle, including whether you consume caffeine or use tobacco products or alcohol.
• Medications, supplements and vitamins you take.

What tests diagnose a junctional rhythm?

Your provider may perform an electrocardiogram (EKG) to check for a junctional rhythm or another type of arrhythmia. Your provider sticks electrodes (pads) on your chest, arms and legs that are connected to a special computer. This noninvasive test measures and records your heart’s rhythm.

Your EKG shows a series of lines with curves and waves that indicate how your heart is beating. If you have a junctional rhythm, a small wave called a “P wave” is either inverted (upside down) or missing on your EKG.

An EKG can often diagnose a junctional rhythm. But you may need further testing to check your heart health, such as:

• Echocardiogram: This ultrasound of the heart can show how well blood is pumping through your heart.
• Stress test: This test can find arrhythmias that start or get worse when you exercise. Stress tests can also help diagnose some types of heart disease or coronary artery disease.
• Tilt table test: During this test, you lie on a table. Your provider measures your heart rhythm and blood pressure as the table tilts your body at different angles. This may diagnose other causes of the abnormal rhythm.

How is a junctional rhythm treated?

If you don’t have other heart problems and you don’t have symptoms, you may not need treatment for a junctional rhythm. Your provider may recommend regular checkups and EKGs to monitor your heart health.

You may need treatment if your blood oxygen levels are too low or your symptoms bother you. Your treatment may include:

• Medication changes: Your provider may change the dose or type of medications you take if your current medications are causing the junctional rhythm. Medications that speed up or slow down your heart rate may also be an option, depending on your needs.
• Permanent pacemaker: Your provider implants this device in your heart. Pacemakers send electrical impulses and can correct many kinds of arrhythmias. A pacemaker can take the place of your SA node to help your heart beat.

How can I prevent a junctional rhythm?

There is no guaranteed way to prevent this condition. Sometimes it happens without an obvious cause. To prevent a junctional rhythm from getting worse, see your provider regularly. At these visits, you and your provider can discuss:

• Any symptoms you have or any health changes you notice.
• How your pacemaker is working, if you have one.
• If your medications are working well for you and if you have any side effects.

Are there other conditions that put me at higher risk of a junctional rhythm?

Having heart surgery or a heart transplant may increase your risk of a junctional rhythm. But once your heart has healed after surgery, the junctional rhythm may go away. Having another heart condition, especially another type of arrhythmia, also puts you at a higher risk of having a junctional rhythm.

What is the outlook for a junctional rhythm?

A junctional rhythm usually doesn’t cause serious health problems and may go away with treatment. Even though there is no cure for a junctional rhythm, your provider can help you manage your symptoms. Managing any symptoms and getting treatment can help you feel your best.

How do I take care of myself with a junctional rhythm?

You can live a healthy life with a junctional rhythm if you:

• Follow your provider’s instructions for maintaining your pacemaker if you have one.
• See your provider for checkups or follow-up visits regularly.
• Take medications as prescribed by your provider. Don’t stop taking them unless your provider tells you to do so.
• Tell your provider if you have new symptoms or if your symptoms get worse.

When should I see my healthcare provider?

See your provider if you notice:

• New symptoms or health changes.
• Side effects from your medications.
• Your symptoms are getting worse or they prevent you from doing daily activities.

A note from Cleveland Clinic

Many people can manage a junctional rhythm with regular visits to their healthcare provider. But if you need treatment, medications or a pacemaker can often relieve your symptoms. A junctional rhythm doesn’t have to stop you from doing things you love. With regular medical care, many people live full, healthy lives with a junctional rhythm.