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Tachycardia: Difference between revisions
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→AV node arrhythmias
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====Management:==== | ====Management:==== | ||
Termination is possible by vagal manoeuvres (blowing on the wrist, carotid sinus massage) or medication (adenosine, verapamil, diltiazem). If manoeuvres or medication fails electrocardioversion can be performed. | Termination is possible by vagal manoeuvres (blowing on the wrist, carotid sinus massage) or medication (adenosine, verapamil, diltiazem). If manoeuvres or medication fails electrocardioversion can be performed. | ||
===AV Nodal Re-entry Tachycardia (AVNRT)=== | |||
====Pathophysiology:==== | |||
AVRT are tachycardias with a re-entry circuit compromising the entire heart. Atria, AV-node, ventricle and an extra bundle are an essential part of this circuit. The pre-requisite of an AVRT is the existence of an extra bundle between the atria and ventricle. This bundle can bypass the AV-node. | |||
The following bundles exist: | |||
* Bundle of Kent: A connection between atria and ventricles most often located on the lateral side of the atria\ventricles. | |||
* Lown-Ganong-Levine bundle: A connection between the atria and the bundle of His, effectively bypassing the AV-node. | |||
* Maheim-Bundle: A connection between AV conduction system and ventricles with AV-like conduction properties. | |||
Depending on the conduction characteristics of the bundle and the direction of conduction two different AVRT circuits can manifest: | |||
* Orthodrome AV re-entry tachycardia: The impulse travels through the normal conduction system and returns to the atria via the accessory bundle. | |||
* Antidrome AV re-entry tachycardia: The impulse travels antrograde through the accessory bundle and activates the ventricles. The impulse returns through the normal conduction system to the atria. | |||
====Clinical diagnosis:==== | |||
* Orthodrome AV re-entry tachycardia: There is a P-wave (other morphology than sinus rhythm) followed by small QRS-complex | |||
* Antidrome AV re-entry tachycardia: The tachycardia resembles a broad-complex tachycardia and is follow by a retrograde P-wave originating from the AV-node. | |||
====Management:==== | |||
Anti-arrhythmic drugs or ablation | |||
==AVRT== | ==AVRT== | ||