AV reentry utilizing an accessory pathway, known as AV reentry, or AV reciprocating tachycardia (AVRT), can present clinically with a narrow QRS complex virtually identical to AVNRT. This occurs when the accessory pathway dependent tachycardia utilizes the AV node and His-Purkinje system in an anterograde direction and the accessory pathway in a retrograde direction, and is termed orthodromic reciprocating tachycardia, or ORT. This SVT, however, typically shows a longer RP greater than 0.09 seconds and a WPW pattern may be seen after conversion to sinus rhythm. The accessory pathway, however, may conduct only in a retrograde direction, termed concealed WPW, so the absence of a WPW pattern in sinus rhythm does not exclude AVRT. The following animation illustrates what we have just described.