AV reentrant tachycardia

Pathophysiology
Electrical activity of the heart is rerouted through an accessory pathway that connects the atria with the ventricles. Two types of tachycardias fall under this category. Antegrade Reentrant Tachycardia and Retrograde Reentrant Tachycardia.

Antegrade conduction is the progression of electrical activity from the atria to the ventricals through an accessory pathway. This leads to a pre mature activation of the ventrical and shows on ECG as a delta wave during sinus rhythm.

Antegrade Reentrant Tachycardia is caused when the electrical activity progresses from the atria to the ventrical through the accessory pathway and reenters the atria through the HIS Bundle. This circular progression continues and overrides the normal conduction system.

Retrograde Reentrant Tachycardia is the reverse circuit. The electrical activity progresses normally from the atria down the HIS bundle, but reenters the atria through the accessory pathway. This circular progression continues and overrides the normal conduction system.

Video
Below is a video explaining the mechanism of AV re-entrant tachycardia

Related Chapters
Wolff-Parkinson-White syndrome

Lown-Ganong-Levine syndrome