Introduction to Junctional Rhythms


This page provides an introduction to junctional rhythms and links to training materials on this website.

The SA node is the normal origin of the electrical impulse for a heart beat. When the SA node cannot perform this role, the atrioventricular (AV) node may take-over pacemaking. When this occurs, the EKG will likely have distinctive waveform features that reveal important aspects of these junctional rhythms.

Junctional rhythms include:

  • Accelerated Junctional Rhythm
  • Junctional Escape Rhythm
  • Junctional Tachycardia
  • Premature Junctional Complex

Junctional Rhythm Categories

Accelerated Junctional Rhythm

Accelerated Junctional Rhythm EKG tracing Accelerated junctional rhythm occurs when the AV junction fires impulses at above 60 bpm. Rhythm will be very regular. The QRS complex is narrow (0.10 sec or less).

Junctional Escape Rhythm

Junctional Escape rhythm EKG tracing Junctional escape beats originate in the AV junction and are late in timing. They often occur during sinus arrest or after premature atrial complexes. The QRS complex will be measured at 0.10 sec or less. Rhythm will be regular with a rate of 40-60 bpm.

Junctional Tachycardia

Junctional Tachycardia EKG tracing This abnormal rhythm originates in the bundle of His. It is observed as three or more premature junctional complexes (PJCs) appearing in a row. Heart rate will be over 100 bpm.

Premature Junctional Complex

Premature Junctional Complex EKG tracing Premature junctional complex (PJC) occurs when an irritable site witinin the AV node fires an impulse before the SA node. This impulse interrupts the sinus rhythm. The QRS complex will be narrow, usually measured at 0.10 sec or less.

Training Resources

Junctional Rhythm Training

A good starting point for learning is our junctional rhythms module. This module focuses on the morphologic features and qualifying criteria of junctional rhythms. A concise summary of a five step EKG analysis methodology is also included.

Junctional Rhythms

EKG Rhythm Tests

Hundreds heart rhythms in this practice test. Test can be tailored for specific learning needs.

EKG Rhythm Tests

Heart Rhythm Quiz also has a heart rhythm quiz that is similar to a written exam. Twenty tracings are presented. Feedback as you progress. Score at the end.

ECG Quiz

ECG Monitor Challenge

Another type of quiz uses a simulated patient monitor. You must evaluate a scrolling waveform rather than a paper tracing.

ECG Monitor Challenge

External References

Free Dictionary