Invasive electrophysiology A long RP tachycardia – an electrophysiological puzzle

Abstract

A case of a 30-year-old male with paroxysmal long RP tachycardia is presented. During electrophysiological study the clinical arrhythmia (atypical atrioventricular nodal reentrant tachycardia – AVNRT) was misdiagnosed as ectopic left atrial tachycardia due to ventricle-atrium-atrium-ventricle (VAAV) response after entrainment, eccentric atrial activation sequence and easiness in achieving atrio-ventricular dissociation with ventricular pacing during the tachycardia. Reassessment of the VAAV response lead to recognition of pseudo-VAAV response often seen in atypical, fast-slow AVNRT. Subsequent ablation of the slow pathway at standard site in the triangle of Koch was successful in eliminating the tachycardia.