Click on image to view larger version.

Figure 3 Complete AV block resulting from mechanical catheter-induced trauma to both a manifest right anteroseptal accessory pathway and the AV node (Patient 4A). (A) Manifest preexcitation is present in sinus rhythm at baseline. (B) Orthodromic AV reentrant tachycardia (260 beats/min) is induced at the beginning of the electrophysiologic study suggesting an excellent retrograde conduction over the right anteroseptal accessory pathway. (C) Complete AV block with junctional escape rhythm (75 beats/min) follows simultaneous mechanical trauma to both the accessory pathway and the AV node with the ablation catheter. Note the absence of retrograde conduction during junctional rhythm.