Zero‐fluoroscopy cryothermal ablation of atrioventricular nodal re‐entry tachycardia guided by endovascular and endocardial catheter visualization using intracardiac echocardiography (Ice&ICE Trial)

1 Introduction

Stochastic damage of the ionizing radiation to both patients and medical staff is a drawback of fluoroscopic guidance during catheter ablation of cardiac arrhythmias. Therefore, emerging zero‐fluoroscopy catheter‐guidance techniques are of great interest.

2 Methods and results

We investigated, in a prospective pilot study, the feasibility and safety of the cryothermal (CA) slow‐pathway ablation in patients with symptomatic atrioventricular‐nodal‐re‐entry‐tachycardia (AVNRT) using solely intracardiac echocardiography (ICE) for endovascular and endocardial catheter visualization. Twenty‐five consecutive patients (mean age 55.6 ± 12.0 years, 17 female) with ECG‐documentation or symptoms suggesting AVNRT underwent an electrophysiology study (EPS) in our laboratory utilizing ICE for catheter navigation. Supraventricular tachycardia was inducible in 23 (92%) patients; AVNRT was confirmed by appropriate stimulation maneuvers in 20 (80%) patients. All EPS in the AVNRT subgroup could be accomplished without need for fluoroscopy, relying solely on ICE‐guidance. CA guided by anatomical location and slow‐pathway potentials was successful in all patients, median cryo‐mappings = 6 (IQR:3–10), median cryo‐ablations = 2 (IQR:1–3). Fluoroscopy was used to facilitate the trans‐septal puncture and localization of the ablation substrate in the remaining 3 patients (one focal atrial tachycardia and two atrioventricular‐re‐entry‐tachycardias). Mean EPS duration in the AVNRT subgroup was 99.8 ± 39.6 minutes, ICE guided catheter placement 11.9 ± 5.8 minutes, time needed for diagnostic evaluation 27.1 ± 10.8 minutes, and cryo‐application duration 26.3 ± 30.8 minutes.

3 Conclusions

ICE‐guided zero‐fluoroscopy CA in AVNRT patients is feasible and safe. Real‐time visualization of the true endovascular borders and cardiac structures allow for safe catheter navigation during the ICE‐guided EPS and might be an alternative to visualization technologies using geometry reconstructions.