Cryoablation of the Retrograde Fast Pathway as Treatment for AVNRT

Study Overview
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Brief Summary
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In this study a new technique for ablation in atrioventricular nodal reentrant tachycardia using cryo-energy will be studied in cases where the standard approach has higher risk.

Detailed Description
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Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common cause of fast heartbeats in young people. People with AVNRT have two pathways within the heart, the fast pathway (FP) and slow pathway (SP). A treatment for AVNRT is ablation (burning or freezing) of the SP. This can be done with either radiofrequency or cryo-energy. A complication which occurs in 1% of cases is AV block (AVB), meaning the person needs a pacemaker. Slow pathway ablation is a problem in people when the electrocardiogram (ECG) shows a long PR interval, with greater rates of AVB. This accounts for 5% of AVNRT cases. A possible solution is to treat the FP with cryo-energy and leave the SP intact. This pilot study aims to show this is safe and effective.

Official Title
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Cryoablation of the Retrograde Fast Pathway as Treatment for AVNRT

Conditions
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Atrioventricular Node Arrhythmia

Intervention / Treatment
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* Procedure: Cardiac catheter ablation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Documented supraventricular tachycardia (SVT) Planned to undergo electrophysiology (EP) study and ablation PR interval on ECG <220ms (Group 1) or >220ms (Group 2) Exclusion Criteria: Pregnancy Age <18 years Inability to provide consent High likelihood of tachycardia mechanism other than AVNRT (e.g. Pre-excitation on surface ECG, atrial tachycardia)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Prospective model with two groups based on PR interval on ECG, normal and prolonged PR
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Mapping<br>Standard treatment involving ablation of the slow pathway with cryotherapy | Procedure: Cardiac catheter ablation<br>* Cryoablation<br>|
| Experimental: Ablation<br>Mapping and ablation of the retrograde fast pathway with cryotherapy | Procedure: Cardiac catheter ablation<br>* Cryoablation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Termination of AVNRT | Number of participants where cryotherapy terminates AVNRT | One day | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Freedom from recurrence | Number of participants with no recurrence of AVNRT during follow-up | 1 year | 
| Incidence of AV block | Number of participants where AV block is observed | 1 year | 
| Cardiac tamponade | Number of participants with pericardial effusion and/or tamponade following procedure | 1 year | 
| Vascular complications | Number of participants with groin hematoma or fistula requiring intervention following procedure | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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AVNRT, Cryoablation, PR interval