A report on Atrioventricular node and AV nodal reentrant tachycardia

Image showing the conduction system of the heart. The AV node is labelled 2.
An example of an ECG tracing typical of uncommon AV nodal reentrant tachycardia. Highlighted in yellow is the P wave that falls after the QRS complex.
Isolated heart conduction system showing atrioventricular node
During typical AVNRT, electrical impulses travel down the slow pathway of the AV node and back up the fast pathway.
AVNRT termination following administration of adenosine

AVNRT occurs when a reentrant circuit forms within or just next to the atrioventricular node.

- AV nodal reentrant tachycardia

Atrioventricular nodal re-entry tachycardia.

- Atrioventricular node
Image showing the conduction system of the heart. The AV node is labelled 2.

2 related topics with Alpha

Overall
Ventricular fibrillation (VF) showing disorganized electrical activity producing a spiked tracing on an electrocardiogram (ECG)

Arrhythmia

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Too fast or too slow.

Too fast or too slow.

Ventricular fibrillation (VF) showing disorganized electrical activity producing a spiked tracing on an electrocardiogram (ECG)
Broad classification of arrhythmias according to region of heart required to sustain the rhythm
Normal sinus rhythm, with solid black arrows pointing to normal P waves representative of normal sinus node function, followed by a pause in sinus node activity (resulting in a transient loss of heartbeats). Note that the P wave that disrupts the pause (indicated by the dashed arrow) does not look like the previous (normal) P waves – this last P wave is arising from a different part of the atrium, representing an escape rhythm.

AV nodal reentrant tachycardia

The impulse initially causes both atria to contract, then activates the atrioventricular node (AV node), which is normally the only electrical connection between the atria and the ventricles (main pumping chambers).

Leads aVL and aVF of an electrocardiogram showing atrial fibrillation. There are irregular intervals between heart beats. No P waves are seen and there is an erratic baseline between QRS complexes. The heart rate is about 125 beats per minute.

Atrial fibrillation

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Abnormal heart rhythm (arrhythmia) characterized by rapid and irregular beating of the atrial chambers of the heart.

Abnormal heart rhythm (arrhythmia) characterized by rapid and irregular beating of the atrial chambers of the heart.

Leads aVL and aVF of an electrocardiogram showing atrial fibrillation. There are irregular intervals between heart beats. No P waves are seen and there is an erratic baseline between QRS complexes. The heart rate is about 125 beats per minute.
Normal rhythm tracing (top) Atrial fibrillation (bottom)
How a stroke can occur during atrial fibrillation
Non-modifiable risk factors (top left box) and modifiable risk factors (bottom left box) for atrial fibrillation. The main outcomes of atrial fibrillation are in the right box. BMI=Body Mass Index.
A 12-lead ECG showing atrial fibrillation at approximately 132 beats per minute
Diagram of normal sinus rhythm as seen on ECG. In atrial fibrillation the P waves, which represent depolarization of the top of the heart, are absent.
ECG of atrial fibrillation (top) and normal sinus rhythm (bottom). The purple arrow indicates a P wave, which is lost in atrial fibrillation.
3D Medical Animation still shot of Left Atrial Appendage Occlusion

These disorganized waves conduct intermittently through the atrioventricular node, leading to irregular activation of the ventricles that generate the heartbeat.

Other inherited heart conditions associated with the development of atrial fibrillation in children include Brugada syndrome, short QT syndrome, Wolff Parkinson White syndrome, and other forms of supraventricular tachycardia (e.g., AV nodal reentrant tachycardia).