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Accelerated Junctional Rhythm - ECG

Accelerated junctional rhythm

Junctional Rhythm
ECG and Junctional Rhythm
Accelerated Junctional Rhythm
Accelerated Junctional Rhythm - Most Common Causes

Junctional Rhythm

AV junction (AV node, Bundle of His) depolarization vectors

In junctional rhythm, impulses originate in the AV junction

The AV junction consists of the AV node and the His bundle

Each impulse then spreads from the AV junction

To the atria (resulting in a negative - retrograde P wave)
To the ventricles (resulting in a QRS complex)

Junctional rhythm has a frequency of 40-60/min.
Junctional rhythm is a secondary pacemaker, activated when:

impulses stop arriving at the AV junction
impulses arriving at the AV junction have a lower frequency than the AV junction generates

Junctional rhythm is a protective mechanism, protecting the heart from:

Asystole (ventricular standstill)
Severe sinus bradycardia

If junctional rhythm fails

then a ventricular rhythm - a tertiary pacemaker - is activated

ECG and Junctional Rhythm

Retrograde P waves and AV junction depolarization vectors

Retrograde (negative) P wave

Negative in inferior leads (II, III, aVF)
Positive (aVR, V1)
The P wave may be before, within, or after the QRS complex

Narrow QRS complexes (< 0.12s)
- QRS may be wide if aberrant conduction is present
Frequency: 40 - 60/min.
Heart rate is regular (PP and RR intervals do not change)

upper Atrioventricular junctional rhythm

Upper Junctional Rhythm
P wave is before the QRS

middle Atrioventricular junctional rhythm

Middle Junctional Rhythm
P wave is hidden within the QRS

lower Atrioventricular junctional rhythm

Lower Junctional Rhythm
P wave is after the QRS

Junctional Rhythm

Frequency: 50/min.
Heart rate is regular: RR interval is constant
Retrograde P wave: negative P wave before QRS complexes
PQ interval: shortened (< 0.12s)
QRS complex: narrow (< 0.12s)
Upper Junctional Rhythm

Retrograde P wave is before the QRS complexes

Accelerated Junctional Rhythm

Accelerated Junctional Rhythm is a junctional rhythm with a frequency of 60 - 100/min.
According to frequency, junctional rhythm is classified as:

Junctional Bradycardia: < 40/min.
Junctional Rhythm: 40 - 60/min.
Accelerated Junctional Rhythm: 60 - 100/min.
Junctional Tachycardia: > 100/min.

Accelerated Junctional Rhythm - Most Common Causes

Digoxin Intoxication (most common cause of accelerated junctional rhythm)
Myocardial Infarction

lower accelerated AV Atrioventricular junctional rhythm

Accelerated Junctional Rhythm

Frequency: 75/min.

Frequency is 60 - 100/min.

Heart rate is regular: RR interval is constant
Retrograde P waves: occur immediately after QRS complexes

This is a lower junctional rhythm (accelerated)

QRS complex is narrow (< 0.12s)

upper accelerated AV Atrioventricular junctional rhythm

ecg upper accelerated av junctional rhythm, 98 bpm

Accelerated Junctional Rhythm

Frequency: 98/min.
Narrow QRS complexes (< 0.12s)
Shortened PQ interval (< 0.12s)
Retrograde P waves are before the QRS

Impulses are generated by the upper part of the AV junction

Accelerated Junctional Rhythm

Frequency: 75/min.
Narrow QRS complexes (< 0.12s)
Retrograde P waves are after the QRS complexes (red arrows)

Impulses are generated by the lower part of the AV junction

ECG upper av junctional accelerated rhythm, 98 bpm

Accelerated Junctional Rhythm

Frequency: 98/min.
Narrow QRS complexes (< 0.12s)
Shortened PQ interval (< 0.12s)
Retrograde P waves are before the QRS

Impulses are generated by the upper part of the AV junction

atrial focal tachycardia, accelerated junctional rhythm, av dissociation, 3rd degree complete av block

ECG atrial focal tachycardia, accelerated junctional rhythm, av dissociation, 3rd degree complete av block

Accelerated Junctional Rhythm and 3rd Degree AV Block

Focal Atrial Tachycardia

Ectopic P waves with frequency: 165/min. (red arrows)

Accelerated Junctional Rhythm

Narrow QRS complexes with frequency 83/min.

AV Dissociation

There are 2 pacemakers in the heart generating impulses independently of each other

Focal pacemaker (P waves)
Junctional pacemaker (QRS complexes)

P waves and QRS complexes are independent of each other

3rd Degree AV Block

Atria and ventricles are electrically isolated from each other
Retrograde P waves do not occur

because the impulse does not pass from the AV junction to the atria

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers

Home /

Accelerated Junctional Rhythm - ECG

Accelerated junctional rhythm

Junctional Rhythm
ECG and Junctional Rhythm
Accelerated Junctional Rhythm
Accelerated Junctional Rhythm - Most Common Causes

Junctional Rhythm

In junctional rhythm, impulses originate in the AV junction

The AV junction consists of the AV node and the His bundle

Each impulse then spreads from the AV junction

To the atria (resulting in a negative - retrograde P wave)
To the ventricles (resulting in a QRS complex)

Junctional rhythm has a frequency of 40-60/min.

Junctional rhythm is a secondary pacemaker, activated when:

impulses stop arriving at the AV junction
impulses arriving at the AV junction have a lower frequency than the AV junction generates

Junctional rhythm is a protective mechanism, protecting the heart from:

Asystole (ventricular standstill)
Severe sinus bradycardia

If junctional rhythm fails

then a ventricular rhythm - a tertiary pacemaker - is activated

ECG and Junctional Rhythm

Retrograde (negative) P wave

Negative in inferior leads (II, III, aVF)
Positive (aVR, V1)
The P wave may be before, within, or after the QRS complex

Narrow QRS complexes (< 0.12s)
- QRS may be wide if aberrant conduction is present
Frequency: 40 - 60/min.
Heart rate is regular (PP and RR intervals do not change)

Upper Junctional Rhythm

P wave is before the QRS

Middle Junctional Rhythm

P wave is hidden within the QRS

Lower Junctional Rhythm

P wave is after the QRS

Junctional Rhythm

Frequency: 50/min.
Heart rate is regular: RR interval is constant
Retrograde P wave: negative P wave before QRS complexes
PQ interval: shortened (< 0.12s)
QRS complex: narrow (< 0.12s)
Upper Junctional Rhythm

Retrograde P wave is before the QRS complexes

Accelerated Junctional Rhythm

Accelerated Junctional Rhythm is a junctional rhythm with a frequency of 60 - 100/min.
According to frequency, junctional rhythm is classified as:

Junctional Bradycardia: < 40/min.
Junctional Rhythm: 40 - 60/min.
Accelerated Junctional Rhythm: 60 - 100/min.
Junctional Tachycardia: > 100/min.

Accelerated Junctional Rhythm - Most Common Causes

Digoxin Intoxication (most common cause of accelerated junctional rhythm)
Myocardial Infarction

Accelerated Junctional Rhythm

Frequency: 75/min.

Frequency is 60 - 100/min.

Heart rate is regular: RR interval is constant
Retrograde P waves: occur immediately after QRS complexes

This is a lower junctional rhythm (accelerated)

QRS complex is narrow (< 0.12s)

Accelerated Junctional Rhythm

Frequency: 98/min.
Narrow QRS complexes (< 0.12s)
Shortened PQ interval (< 0.12s)
Retrograde P waves are before the QRS

Impulses are generated by the upper part of the AV junction

Accelerated Junctional Rhythm

Frequency: 75/min.
Narrow QRS complexes (< 0.12s)
Retrograde P waves are after the QRS complexes (red arrows)

Impulses are generated by the lower part of the AV junction

Accelerated Junctional Rhythm

Frequency: 98/min.
Narrow QRS complexes (< 0.12s)
Shortened PQ interval (< 0.12s)
Retrograde P waves are before the QRS

Impulses are generated by the upper part of the AV junction

Accelerated Junctional Rhythm and 3rd Degree AV Block

Focal Atrial Tachycardia

Ectopic P waves with frequency: 165/min. (red arrows)

Accelerated Junctional Rhythm

Narrow QRS complexes with frequency 83/min.

AV Dissociation

There are 2 pacemakers in the heart generating impulses independently of each other

Focal pacemaker (P waves)
Junctional pacemaker (QRS complexes)

P waves and QRS complexes are independent of each other

3rd Degree AV Block

Atria and ventricles are electrically isolated from each other
Retrograde P waves do not occur

because the impulse does not pass from the AV junction to the atria

Sources

ECG from Basics to Essentials Step by Step
litfl.com
ecgwaves.com
metealpaslan.com
medmastery.com
uptodate.com
ecgpedia.org
wikipedia.org
Strong Medicine
Understanding Pacemakers