Panel A and B . Intracardiac electrograms of young patient with
a repeated procedure for a Mahaim fibre. The successful ablation was
performed conventionally under fluoroscopy with 4 mm non-irrigated tip
catheter, with applications between 8 and 9 o’clock on the tricuspid
annulus. Panel A shows the tracings during antidromic atrioventricular
re-entrant tachycardia (AVRT) with an atrial premature beat (APB) on His
refractoriness (black star) from the HRA catheter (positioned at the
lateral wall of the right atrium) which pre-excites the next ventricular
activation with continuation of tachycardia. Panel B shows an antidromic
AVRT initiation by a paced single atrial premature beat from high right
atrium (black star) with the ablation catheter positioned in the His
region. Notice the reversal of His activation sequence from proximal to
distal activation in sinus rhythm (black big arrow) to distal to
proximal His activation (small black arrows) at initiation and during
antidromic AVRT.
Funding: this research has not received any funding or support
in the means of grants, equipment or drugs.