Supernormal conduction and linking in an accessory AV pathway

Wide complex tachycardia in a patient with non-ischemic cardiomyopathy: What is the diagnosis?

A 55-year-old male presented with acute heart failure and incessant wide complex tachycardia resembling an outflow tract ventricular tachycardia. Meticulous analysis of the electrocardiograms established the diagnosis of pre-excitation with prolonged atrio-ventricular (A-V) conduction over a decremental accessory pathway. 'Linking' between accessory pathway and normal A-V conduction system resulted in sustained maximal pre-excitation as well as periodic transition to normal A-V conduction without appreciable change in heart rate. Successful radiofrequency ablation of this atypical accessory pathway was performed at the aortic-mitral junction. This ameliorated the mechanical dysynchrony, allowed discontinuation of hemodynamic/inotropic support, and resulted in sustained symptomatic improvement. This article is protected by copyright. All rights reserved.