AV reentrant tachycardia
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Varun Kumar, M.B.B.S. [2]
Synonyms and keywords: AVRT; AV-reciprocating tachycardia; atrioventricular reentrant tachycaria
Overview
Classification
Two types of tachycardias fall under this category:
Antegrade Reentrant Tachycardia
Antegrade conduction is the progression of electrical activity from the atria to the ventricals through an accessory pathway. This leads to a premature activation of the ventrical and shows on EKG as a delta wave during sinus rhythm. Antegrade Reentrant Tachycardia is caused when the electrical activity progresses from the atria to the ventricles through the accessory pathway and reenters the atria through the bundle of His. This circular progression continues and overrides the normal conduction system.
Retrograde Reentrant Tachycardia
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.
Causes
Overview
AVRT results from an anatomically distinct atrioventricular connection. The causes, which usually are congenital or genetic, include: Ebstein anomaly, Lown-Ganong-Levine syndrome, Mahaim fiber tachycardia, Wolff-Parkinson-White syndrome.
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.
AV nodal reentrant tachycardia is usually not life-threatening.
Common Causes
Causes by Organ Systems
| Cardiovascular | Ebstein anomaly, Lown-Ganong-Levine syndrome, Mahaim fiber tachycardia, Wolff-Parkinson-White syndrome |
| Chemical/Poisoning | No underlying causes |
| Dental | No underlying causes |
| Dermatologic | No underlying causes |
| Drug Side Effect | No underlying causes |
| Ear Nose Throat | No underlying causes |
| Endocrine | No underlying causes |
| Environmental | No underlying causes |
| Gastroenterologic | No underlying causes |
| Genetic | Ebstein anomaly |
| Hematologic | No underlying causes |
| Iatrogenic | No underlying causes |
| Infectious Disease | No underlying causes |
| Musculoskeletal/Orthopedic | No underlying causes |
| Neurologic | No underlying causes |
| Nutritional/Metabolic | No underlying causes |
| Obstetric/Gynecologic | No underlying causes |
| Oncologic | No underlying causes |
| Ophthalmologic | No underlying causes |
| Overdose/Toxicity | No underlying causes |
| Psychiatric | No underlying causes |
| Pulmonary | No underlying causes |
| Renal/Electrolyte | No underlying causes |
| Rheumatology/Immunology/Allergy | No underlying causes |
| Sexual | No underlying causes |
| Trauma | No underlying causes |
| Urologic | No underlying causes |
| Miscellaneous | No underlying causes |
Causes in Alphabetical Order
Pathophysiology
Electrical activity of the heart is rerouted through an accessory pathway that connects the atria with the ventricles.
Diagnosis
Electrocardiogram
QRS Atlernans
The appearance of QRS alternans as part of a narrow complex tachycardia suggests the diagnosis of orthodromic atrioventricular (AV) reentrant tachycardia which conducts retrograde over an accessory pathway.
Video
Below is a video explaining the mechanism of AV re-entrant tachycardia
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