Impact of high-resolution 3D-mapping with micro-electrodes on catheter ablation of Wolff-Parkinson-White syndrome

Int J Cardiol Heart Vasc. 2024 Jun 5:53:101435. doi: 10.1016/j.ijcha.2024.101435. eCollection 2024 Aug.

Abstract

Background: It is currently unknown whether high-resolution 3D-mapping and micro-electrodes add meaningful benefits in catheter ablation of Wolff-Parkinson-White (WPW) syndrome and challenging, e.g. para-Hisian accessory pathways (APs).

Objectives: To compare the mapping resolution, acute success and complication rates in patients with WPW syndrome undergoing a first-time catheter ablation using only a contact force-sensing ablation catheter for mapping or a multi-electrode high-resolution mapping catheter.

Methods: Fifty consecutive 3D-mapping procedures for WPW syndrome using a 3.5-mm ablation catheter (n = 27) or a multi-electrode high-resolution catheter (n = 23) were retrospectively analyzed regarding mapping resolution defined as first 5/10 msec isochronal activation area, number of RF applications to achieve AP block, occurence of AP automaticity during RF delivery, and acute success and complication rates.

Results: Catheter ablation was successful in 48/50 patients with a median of 1 (IQR 1-2) RF applications. Compared to ablation catheter mapping, high-resolution mapping showed a significantly smaller isochronal activation area in the first 5/10 msec (1.25 ± 0.29 vs 0.15 ± 0.03 cm2; P < 0.001 and 3.41 ± 0.58 vs 0.55 ± 0.12 cm2; P < 0.0001) and significantly higher incidence of AP automaticity during RF delivery (0 vs 22 %; P < 0.05). In para-Hisian APs, micro-electrodes recorded distinct His electrograms and AP potentials without fusion and without AP bumping permitting safe and effective para-Hisian AP ablation.

Conclusions: High-resolution mapping increases the mapping accuracy of the AP and its insertion site leading to a significantly higher incidence of AP automaticity during RF delivery. Micro-electrodes provide clinically relevant advantages in para-hisian AP mapping improving efficacy and safety of para-Hisian AP ablation.