orthodromic AVRT (OAVRT)

<p>If the tachycardia has a narrow QRS complex (orthodromic AVRT), the antegrade limb (ie, the pathway that conducts the impulse to the ventricle) is the AV node/His-Purkinje system; in this setting, the delta wave seen during sinus rhythm is lost since antegrade conduction is not via the accessory pathway (ie, the ventricle is not preexcited).</p>