Ventricular fibrillation during lattice-tip radiofrequency ablation adjacent to ICD coils: a multicenter case series
B Kovacs, C V Malyar, K Kneizeh, N Schaerli, V Spahiu, T Kueffer, A Haeberlin, L Roten, M Kuehne, H Puererfellner, S Yap, T ReichlinAbstract
Background
The novel lattice-tip dual-energy ablation catheter enables both pulsed-field and high-power temperature-controlled radiofrequency (RF) ablation. While generally effective, unexpected ventricular fibrillation (VF) induction has recently been reported during RF ablation in patients with implantable cardioverter-defibrillators (ICD). The causative mechanism remains to be determined.
Purpose
To describe a multicenter experience of inadvertent VF induction during RF energy delivery with the lattice-tip catheter in proximity to ICD high-voltage (HV) leads.
Methods
Six cases from four tertiary centers were identified. In all patients, ablation was performed using the lattice-tip catheter in temperature-controlled RF mode (target 60 °C, ~200 W output depending on total circuit impedance) during ventricular tachycardia (VT) or cavotricuspid isthmus (CTI) ablation, with induction of VF. Pre- and postprocedural device interrogations were performed. Device therapies were disabled during ablation. Fluoroscopic localization of the ablation catheter was obtained at the time of VF induction.
Results
The baseline characteristics of the patients are shown in Table 1. The ablation catheter was located in relative proximity to an HV coil in all cases (3 right-ventricular inferoseptal, 2 left-ventricular inferoseptal, 2 CTI; one patient had induction during both RV and CTI ablation). The approximate fluoroscopic distance between the ablation catheter and the HV coil was 10 mm (5-30). Total circuit impedance and temperature behavior during ablation were as expected. VF was terminated successfully in all patients; in one patient five episodes of VF were induced requiring five shocks. Visible pectoral muscle stimulation at the generator site during RF ablation and simultaneous VF induction was observed in one patient. All ICD generators and HV leads were from the same manufacturer. The HV leads were implanted a median of 13.5 months (3-164) prior to the procedure. Two patients had abandoned HV leads. The median HV impedance prior to the procedure was 68.5 Ω (all within range) and post-procedural change was -2 to 6 Ω except in one patient with a newly implanted biventricular ICD 3 months prior, who had out of range impedance measurements on all three leads and required a generator replacement. Manufacturer analysis revealed damage of the internal circuits. All parameters normalized thereafter. No structural defects of the ablation catheter or HV leads were identified in any of the cases.
Conclusions
Radiofrequency ablation with the lattice-tip dual-energy catheter near an ICD HV coil can precipitate VF, possibly through unintended coupling of the lead–can system into the RF circuit. Awareness of this phenomenon is critical when ablating in the vicinity of ICD leads (RV/LV septum or CTI). Operators should avoid direct RF delivery on or adjacent to HV coils and consider alternative catheters or energy sources in these locations.Table 1.Baseline characteristicsFigure 1