Other conditions can cause wide QRS complexes. Supraventricular tachycardia (SVT) with aberration, for example, causes a wide QRS. SVT has three aberrations: bundle-branch block aberration, Wolff-Parkinson-White syndrome, and other aberrations not associated with bundle-branch block or Wolff-Parkinson-White syndrome.

The most common aberration is SVT with a bundle-branch block. This category includes atrial fibrillation, atrial flutter, atrioventricular tachycardia, and sinus tachycardia with or without P waves with bundle-branch block. The P waves may be hidden inside the T waves of the preceding beat, as seen in cases with long PR intervals.

SVT aberration in Wolf-Parkinson-White syndrome is a rare condition. It occurs when there is an antegrade direction of impulses through the accessory pathway or a concomitant bundle-branch block.

Differentiating Between Ventricular Tachycardia and Supraventricular Tachycardia with Aberration

There are many similarities between VT and SVT with aberration. Appropriate management of these patients requires the correct diagnosis.

On a different note, sometimes artifacts can be misconstrued as wide complex tachycardia. These artifacts are formed during movements such as brushing teeth, insufficient skin and electrode contact, or back-slapping during physiotherapy, to name a few. A distinct feature of artifacts is remnant QRS complexes (notches) within the artifacts and an atypical beginning and end of the artifact VT.