Cryotherapy Versus Radiofrequency Ablation for Treatment of Para-hisian Accessory Pathways

This is a randomized study on the safety and efficacy for percutaneous ablation of para-hisian accessory pathways according to two different modalities: radiofrequency (RF) or cryotherapy.

Thirty patients with symptomatic or high-risk para-hisian accessory pathways, documented by previous electrophysiological study (EPS), referred to percutaneous catheter ablation, will be enrolled in this trial.

After informed consent, these patients will be randomized in 2 groups with different current established strategies of invasive treatment. Group I: electrophysiological mapping and ablation with radiofrequency (RF) focal lesion formation.

Group II: electrophysiological mapping and ablation with cryotherapy (CRYO) focal lesion formation.

The primary outcome will be the recurrence rate of accessory pathway conduction after one year of follow-up. Secondary endpoints will be immediate success and rate of permanent atrioventricular (AV) block.

Inclusion criteria

• Patients with para-hisian accessory pathways, diagnosed by electrophysiological study (EPS), with indication of invasive treatment according to current guidelines. Patients should be willing and able to sign an informed consent form, and to undergo all procedures described in both the study protocol and the consent form.

Exclusion criteria

• Previous cryotherapy ablation;
• Previous extensive radiofrequency ablation (including aortic cusp mapping);
• Age below twelve years;
• Severe coagulation disorder;
• Pregnancy;
• Refusal to participate in the study.