A report on Atrioventricular node and Atrial flutter

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

Atrial flutter with varying A-V conduction (5:1 and 4:1)

Isolated heart conduction system showing atrioventricular node

Type I atrial flutter, counterclockwise rotation with 3:1 and 4:1 AV nodal block.

Atrial flutter with a two to one block. Note the P waves hiding in the T waves in leads V1 and V2

This is the property of the AV node that prevents rapid conduction to the ventricle in cases of rapid atrial rhythms, such as atrial fibrillation or atrial flutter.

- Atrioventricular node

Impulses from the atria are conducted to the ventricles through the atrio-ventricular node (AV node).

- Atrial flutter

3 related topics with Alpha

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.

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.

Supraventricular tachycardias include atrial fibrillation, atrial flutter and paroxysmal supraventricular 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).

Atrial fibrillation

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

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

It may also start as other forms of arrhythmia such as atrial flutter that then transform into AF.

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

Heart

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Muscular organ in most animals.

Computer-generated animation of a beating human heart

The human heart is in the middle of the thorax, with its apex pointing to the left.

Heart being dissected showing right and left ventricles, from above

Frontal section showing papillary muscles attached to the tricuspid valve on the right and to the mitral valve on the left via chordae tendineae.

Layers of the heart wall, including visceral and parietal pericardium

The swirling pattern of myocardium helps the heart pump effectively

Arterial supply to the heart (red), with other areas labelled (blue).

Development of the human heart during the first eight weeks (top) and the formation of the heart chambers (bottom). In this figure, the blue and red colors represent blood inflow and outflow (not venous and arterial blood). Initially, all venous blood flows from the tail/atria to the ventricles/head, a very different pattern from that of an adult.

The cardiac cycle as correlated to the ECG

The x-axis reflects time with a recording of the heart sounds. The y-axis represents pressure.

Transmission of a cardiac action potential through the heart's conduction system

The prepotential is due to a slow influx of sodium ions until the threshold is reached followed by a rapid depolarization and repolarization. The prepotential accounts for the membrane reaching threshold and initiates the spontaneous depolarization and contraction of the cell; there is no resting potential.

3D echocardiogram showing the mitral valve (right), tricuspid and mitral valves (top left) and aortic valve (top right).
The closure of the heart valves causes the heart sounds.

Heart and its blood vessels, by Leonardo da Vinci, 15th century

Elize Ryd making a heart sign at a concert in 2018

The tube-like heart (green) of the mosquito Anopheles gambiae extends horizontally across the body, interlinked with the diamond-shaped wing muscles (also green) and surrounded by pericardial cells (red). Blue depicts cell nuclei.

Basic arthropod body structure – heart shown in red

The human heart viewed from the front and from behind

Heart illustration with circulatory system

Animated Heart 3d Model Rendered in Computer

These generate a current that causes the heart to contract, traveling through the atrioventricular node and along the conduction system of the heart.

These arrhythmias can take many forms and can originate from different structures within the heart—some arise from the atria (e.g. atrial flutter), some from the atrioventricular node (e.g. AV nodal re-entrant tachycardia) whilst others arise from the ventricles (e.g. ventricular tachycardia).