AV nodal re-entry tachycardia (AVNRT)

Abstract

AVNRT is the most common paroxysmal supraventricular tachycardia seen in adults. It occurs as a result of reentry within dual AV pathways (two connections between the atrium and the compact AV node). In typical AVNRT reentry occurs with antegrade conduction down a 'slow' pathway and retrograde conduction up a 'fast' pathway resulting in a short RP tachycardia. In atypical AVNRT, conduction occurs antegrade along the fast pathway and retrograde along the slow pathway resulting a long RP tachycardia. It is important to carefully map during tachycardia and perform the relevant maneuvers in order to establish the diagnosis. AVNRT is treatable with catheter ablation and this is highly successful with a low recurrence rate. AV block is a major potential complication in ablation of AVNRT.