Junctional Rhythm

A junctional rhythm is a type of abnormal heart rhythm (arrhythmia). It happens when your AV (atrioventricular) node sends a heartbeat signal because your heart’s natural pacemaker, called the SA (sinoatrial) node, isn’t working right. Like a backup for your natural pacemaker, your AV node can control your heartbeat if your SA node’s impulses are too slow or weak.

The AV node can keep your heart beating. But it might make your heartbeat slower or faster than normal. A healthcare provider can see the difference on an electrocardiogram (EKG), which records your heart’s electrical activity.

When you have a junctional rhythm:

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

Types of this condition

All types of junctional rhythms occur when the SA node isn’t working as it should. But your heart rate may change based on the faster rate of the backup pacemaker that takes over for the SA node.

A normal adult heartbeat is 60 to 100 beats per minute (bpm). A junctional rhythm can make your heartbeat slower than normal (bradycardia) or faster than normal (tachycardia). Junctional rhythm types 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

Symptoms of junctional rhythm

With only the lower chambers of your heart contracting, your organs and tissues may not get as much oxygen-rich blood. If you have a mild case, you may not feel any different. But if you have a more severe case, you may have junctional rhythm symptoms like:

• Anxiety
• Chest pain
• Dizziness
• Fainting
• Fatigue or weakness
• Heart palpitations
• Shortness of breath

Junctional rhythm causes

Causes of a junctional rhythm include:

• Heart problems, like coronary artery disease, heart attack or trauma
• Inflammation from various causes, like Lyme disease, myocarditis or pericarditis
• Conduction system problems, like sick sinus syndrome or certain heart blocks
• Medical issues, like hypoxia, hypothyroidism or sleep apnea
• Medicines, like beta-blockers, opioids or calcium channel blockers

Risk factors

A junctional rhythm is less common than other arrhythmias. But children or adults may get it if they:

• Recently had a heart transplant or heart surgery (the junctional rhythm may go away once your heart heals)
• Have sinus node dysfunction, also known as sick sinus syndrome
• Have another heart condition, especially another type of arrhythmia

How doctors diagnose this condition

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

• Health history
• Use of caffeine, tobacco products or other addictive substances
• Use of medications, supplements and vitamins

Your provider may do an EKG to check for a junctional rhythm or another type of arrhythmia. This noninvasive test measures and records your heart’s rhythm.

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

An EKG can often diagnose a junctional rhythm. But you may need other tests to check your heart health, like:

• Echocardiogram: This ultrasound of the heart can show how well blood pumps through your heart.
• Stress test: This test can find arrhythmias that start or get worse when you exercise.
• 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 it 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 healthcare provider may suggest regular checkups and EKGs to monitor your heart health.

You may need junctional rhythm 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.
• Cardiac ablation: Your provider may perform this minimally invasive procedure to make scar tissue in certain areas of your heart muscle. The scar tissue helps block abnormal signals in your heart.

When should I see my healthcare provider?

See your provider if:

• You notice new symptoms or health changes
• You have side effects from your medications
• Your symptoms are getting worse or keeping you from doing daily activities

Questions to ask your provider may include:

• Which type of junctional rhythm do I have?
• What treatment do you recommend?
• What caused the abnormal heart rhythm in my case?

What can I expect if I have this condition?

A junctional rhythm usually doesn’t cause serious health problems and isn’t life-threatening. But if you have symptoms that get in the way of your daily life, you may need treatment.

Even though there’s no cure for a junctional rhythm, your provider can help you manage your symptoms.

This abnormal heart rhythm can lead to complications, like enlarged heart muscle (dilated cardiomyopathy) or low blood pressure (hypotension). Your outlook depends on the cause and type of the abnormal heart rhythm.

Is there anything I can do to feel better?

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. Don’t stop taking them unless your provider tells you to.
• Tell your provider if you have new or worsening symptoms.