Statistics from Altmetric.com
A 36 year old man with no cardiac structural abnormalities had a 12 year history of paroxysmal tachycardia. At electrophysiologic study, an idiopathic left ventricular tachycardia (VT) with right bundle branch block, left axis deviation (A) was easily inducible by atrial pacing. The figure shows deployment of the multiple electrode array (MEA; Ensite 3000, Endocardial Solutions, Inc), coronary sinus (CS), right ventricular apex (RVA), HIS, and ablation catheters in a right (B) and left (C) anterior oblique view. The MEA is part of a non-contact mapping system that permits mapping of a single complex. The system calculates electrograms from 3000 endocardial points simultaneously by reconstructing far-field signals. Non-depolarised myocardium is shown in purple in this three dimensional isopotential map (right (D) and left (E) anterior oblique view with the Ensite system). Using a conventional 4 mm tip ablation catheter, sharp Purkinje potentials (D) were recorded in this region 55 ms before the earliest QRS deflection. During sinus rhythm, the computer generated map demonstrated progressive activation of the posterior fascicle; 35 ms before earliest ventricular activation depolarisation occurred in the septum where it spread down the left posterior fascicle. The site where depolarisation spread from the His-Purkinje system into the myocardium exactly matched to the earliest activation during VT (D/E). At this target site, radiofrequency ablation (ABL, RF) immediately terminated the VT, which, thereafter, was no longer inducible. This case shows the potential feasibility and usefulness of non-contact activation mapping in exactly localising the exit of an idiopathic VT and in determining the relation of this VT to the intraventricular conduction system.