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 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 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.
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 (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.