What Is a Junctional Rhythm?

A junctional rhythm is a type of abnormal heartbeat, or arrhythmia. It is usually not serious, although it can be associated with heart inflammation or recent heart surgery. It happens when the atrioventricular (AV) node or "His bundle," both of which are electrical signals that help control your heartbeat, isn't working properly.

This article discusses a junctional rhythm and its symptoms, causes, and treatments.

What Is a Junctional Rhythm?

The heart has electrical pulses controlled by cell groups called nodes. The sinoatrial node, or SA node, makes a signal that causes the heart's two upper chambers to contract. These two chambers are called the atria. The SA node is often called the pacemaker of the heart. That's because the SA node typically regulates the heart's atria to contract 60 to 100 times each minute.

Once the atria contract, the signal continues through the AV node to the heart's lower chambers (the ventricles) and causes them to contract.

The SA and AV nodes work with the His bundle, located near the middle of your heart. The fibers within the His bundle conduct electricity in the heart.

A junctional rhythm happens when an abnormal heart rhythm comes from the AV node or His bundle. Although the heart has other areas that can serve as its natural pacemaker when a junctional rhythm occurs, these other areas may cause your heartbeat to become faster or slower.

What Are the Four Types of Junctional Rhythm?

There are four types of junctional rhythm. Each type is determined by how fast or slow the heart beats. These include:

• Junctional bradycardia: Less than 40 beats per minute
• Junctional escape rhythm: 40 to 60 beats per minute
• Accelerated junctional rhythm: 60 to 100 beats per minute
• Junctional tachycardia: More than 100 beats per minute
  

Symptoms

A junctional rhythm does not always have symptoms. If there are symptoms, they are often associated with a rhythm's underlying cause.

Some of the more general symptoms include:

• Dizziness
• Syncope (fainting) or presyncope (feeling like you're about to faint)
• Fatigue
• Heart palpitations
  

What Causes Junctional Rhythm?

A junctional rhythm can have many potential causes, including causes that relate to other health issues and the use of certain medications. Causes of a junctional rhythm include:

• Beta-blockers
• Calcium channel blockers
• Coronary artery disease
• Heart failure
• Hypothyroidism (underactive thyroid)
• Lyme disease
• Myocarditis, or inflammation of the heart
• Opioids
• Recent heart surgery
• Repair of congenital heart disease
• Rheumatic fever
• Sleep apnea
• Heart blocks (when the heart's electrical signals from the top chambers to the lower chambers slow or completely stop)

Tests to Diagnose a Junctional Rhythm

To help diagnose a junctional rhythm, healthcare providers will conduct a physical exam and ask health-related questions, such as what medications or supplements you use. They also may ask if you consume caffeine or alcohol or if you smoke.

Tests that healthcare providers may use to diagnose a junctional rhythm include:

• Electrocardiogram (ECG or EKG): An ECG (or EKG) measures your heart's rhythm and produces a printout of the information. Among the lines, curves, and waves of a normal EKG printout is something called a P wave. The P wave is missing or upside down if you have a junctional rhythm.
• Echocardiogram: This is an ultrasound that shows blood going through the heart.
• Cardiac stress test: This test shows how your heart responds when it is beating faster.
• Tilt table test: This test requires you to lie on a table and have your heart rate and blood pressure taken as the table tilts at different angles.
  

Treatment

A junctional rhythm does not always require treatment. If no other heart problems are found, your healthcare provider may monitor your heart health over time.

If the cause of your junctional rhythm is a specific type of medication, your healthcare provider may change your dosage or find an alternate medicine. Always talk to your healthcare provider before stopping or changing your medications.

Other treatments for a junctional rhythm include:

• Medications to help control your heart rate
• A pacemaker, which sends electrical signals to the heart to ensure your heart beats properly

When to See a Healthcare Provider

If you're diagnosed with a junctional rhythm, you should see your healthcare provider again beyond regular checkups if you:

• Feel as if your symptoms are getting worse
• Experience medication side effects
• Have other recent health changes that your healthcare provider should know
  

Summary

A junctional rhythm is an abnormal heartbeat caused by the AV node or His bundle, electrical pulses that help maintain a regular heartbeat. It is not usually serious. A junctional rhythm does not always have symptoms but can include dizziness, fainting (or the feeling that you might faint), fatigue, or heart palpitations. There are many causes for junctional rhythm, including underlying conditions and medications.

If you or your healthcare provider suspects a junctional rhythm, they will likely order several tests to help make a diagnosis. Treatment includes medication, a pacemaker, and general heart monitoring.

A Word From Verywell

You can live a healthy, active life with a junctional rhythm. Maintain appointments with the healthcare provider who monitors your junctional rhythm. Take any medications that you are prescribed. Plan to eat a heart-healthy diet and get regular physical activity.