Any tachycardic rhythm with a left or right bundle branch block that is NOT ventricular tachycardia is considered "supraventricular tachycardia with aberrancy". This would even include sinus ...

Atrial fibrillation with an uncontrolled ventricular response Left bundle branch block Premature ventricular contractions At times it can be difficult to distinguish "SVT with aberrancy" from ...