Table 4

Differential Diagnosis of Wide–QRS Complex Tachycardia

Mechanism
Ventricular tachycardia
SVT with pre-existing bundle-branch block or intraventricular conduction defect
SVT with aberrant conduction due to tachycardia (normal QRS when in sinus rhythm)
SVT with wide QRS related to electrolyte or metabolic disorder
SVT with conduction over an accessory pathway (pre-excitation)
Paced rhythm
Artifact

SVT indicates supraventricular tachycardia.