What is SVT aberrancy?
Any tachycardic rhythm with a left or right bundle branch block that is NOT ventricular tachycardia is considered “supraventricular tachycardia with aberrancy”.
What causes SVT with aberrancy?
SVT typically originates in atrial tissue and/or AV junction and utilizes the normal atrioventricular (AV) conduction system for ventricular activation. Aberrance occurs when there is delay or block in the His-Purkinje system during antegrade conduction of impulses over the normal AV fascicles.
What is the mechanism of SVT?
The most common cause of SVT is an orthodromic reentry phenomenon, which occurs when the tachycardia is secondary to normal anterograde electrical conduction from the atria to the AV node to the ventricles, with retrograde conduction via an accessory pathway from the ventricles back to the atrial.
How can aberrancy determine SVT?
The likelihood of SVT with aberrancy is increased if:
- Previous ECGs show a bundle branch block pattern with identical morphology to the broad complex tachycardia.
- Previous ECGs show evidence of WPW (short PR < 120ms, broad QRS, delta wave)
What is aberrancy rhythm?
Aberrant ventricular conduction is a common electrocardiographic (EKG) manifestation that occurs when the supraventricular electrical impulse is conducted abnormally through the ventricular conducting system. This results in a wide QRS complex that may be confused with a ventricular ectopic beat.
How can you tell the difference between SVT aberrancy and Vtach?
Differentiating between SVT with aberrancy versus VT can be very difficult….Lead V1 morphology consistent with VT:
- R wave > 30 msec (PPV 0.96)
- RS interval > 60 msec (PPV 0.96), as measured from R wave onset to S wave nadir.
- Notched S Wave (Josephson’s Sign)
How do you treat aberrancy SVT?
If SVT with aberrancy, treat with IV adenosine (vagal maneuvers). For irregular WCTs, if atrial fibrillation with aberrancy, consider expert consultation; control rate. If pre-excited atrial fibrillation (AFIB + WPWS), expert consultation is advised. Avoid AV nodal blocking agents, consider amiodarone.
What are the 3 types of SVT?
The 3 types of supraventricular tachycardia (SVT) include atrioventricular nodal reentrant tachycardia, atrioventricular reciprocating tachycardia, and atrial tachycardia.
What causes SVT to develop?
Most of the time, SVT happens without any obvious reason. It often starts when you are in your teens or early 20s. Sometimes you are born with abnormal pathways or electrical circuits in your heart. Faulty circuits can also form out of scar tissue left behind after surgery.
What is the difference in SVT and VT?
Tachycardia can be categorized by the location from which it originates in the heart. Two types of tachycardia we commonly treat are: Supraventricular tachycardia (SVT) begins in the upper portion of the heart, usually the atria. Ventricular tachycardia (VT) begins in the heart’s lower chambers, the ventricles.
What are aberrancy beats?