VT versus SVT

Tue, 08 Oct 2024 00:00:00 +0000

Regular broad complex tachycardias can be ventricular (VT) or supraventricular (SVT with aberrancy) in origin, and differentiation between the two will significantly influence management of your patients.

Unfortunately, the electrocardiographic differentiation of VT from SVT with aberrancy is not always possible.

Differential diagnosis of regular broad complex tachycardia

Ventricular tachycardia (VT)
Supraventricular tachycardia (SVT) with aberrant conduction due to bundle branch block
SVT with any metabolic disturbance that slows supraventricular action potential propagation — hyperkalaemia, sodium channel blockade, severe acidosis
Antidromic AVRT — re-entrant tachyarrhythmia seen in Wolff-Parkinson-White syndrome
Accelerated idioventricular rhythm (AIVR)

ECG features increasing the likelihood of VT

Electrocardiographic features that increase the likelihood of VT include:

Dressler beat

Mon, 30 May 2022 00:00:00 +0000

Description

Dressler beat: Specifically a ‘ventricular fusion beat‘ in the presence of paroxysmal ventricular tachycardia. Typically observed in ECG tracings of wide complex tachycardia such as VT with AV dissociation.

Supraventricular and a ventricular impulses coincide to produce a hybrid complex which is different to the VT complex and the native complex (capture beat)

The term ‘fusion beat‘ was originally used to define any hybrid QRS complex of atria or ventricular origin. Fusion beats (and capture beats) are not ‘diagnostic‘ or ‘pathognomic‘ of VT and can occur in any arrhythmia (including SVT with aberrancy for example)

Dressler Beat on ECG Library – LITFL Basics

VT versus SVT

Differential diagnosis of regular broad complex tachycardia

ECG features increasing the likelihood of VT

Dressler beat