Monitoring the diaphragm during heart ablation for atrial fibrillation with the Circle Safe System
Tests a catheter that tracks diaphragm response during ablation in people with atrial fibrillation.
Plain-language title generated from the registry record
Registry title: First-in-Human Study of the Circle Safe System for Diaphragm Response Monitoring During Pulmonary Vein Ablation
Key facts
- Where
- Auckland, New ZealandSee the site
Could this be for you?
Answer for yourself. This is not a decision: only the study team can say whether you can take part.
- Are you between 19 and 84 years old?
Source: NCT07820631, who can take part
Where in New Zealand
- Auckland City HospitalAuckland, New ZealandNo longer taking part
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Circle Safe, Inc.
- Trial code
- NCT07820631
- Record updated
- 15 September 2026
- Original description
The objective of this first-in-human study is to evaluate the safety and performance of the Circle Safe System in subjects undergoing pulmonary vein ablation for atrial fibrillation.Read full original descriptionShow less
Evaluation of the Safety and Effectiveness of the Circle SAFE System for Diaphragmatic Compound Motor Action Potential (CMAP) Recording and Display of Patients Undergoing Pulmonary Vein Ablation Procedures. The SAFE-CMAP Clinical Trial
The objective of this first-in-human study is to evaluate the safety and performance of the Circle Safe System in subjects undergoing pulmonary vein ablation for atrial fibrillation.
The main questions it aims to answer are:
* Can the Circle Safe System consistently stimulate the phrenic nerve and record a stable electrical response from the diaphragm? * Can it reliably display changes in the diaphragm's response during ablation? * What device-related or procedure-related medical problems occur during the study? There is no comparison group. All participants will undergo their planned pulmonary vein ablation while the Circle Safe System is used during treatment of the right pulmonary veins.
Participants will:
* Complete standard assessments before the procedure * Have the Circle Safe catheter placed in the superior vena cava during the ablation procedure * Have their phrenic nerve stimulated and their diaphragm response monitored using the Circle Safe System * Be evaluated for device-related and procedure-related safety events through hospital discharge
Inclusion: Male or females >18 and ≤ 85 years of age; Subject willing to sign informed consent; Subject is a candidate for pulmonary vein ablation for the treatment of atrial fibrillation ablation procedures therapy.
Exclusion: Subjects with inadequate venous access due to prior vein thrombosis or indwelling chronic ports or catheters; Subjects with known neuromuscular disease or other medical history (i.e trauma, surgery) that could have impacted diaphragmatic function; Subjects with pacemaker or defibrillator leads placed through the vena cava; Subjects with implantable vena cava filter; Subjects with a contraindication to contrast dye; Pregnant subjects; Subjects participating in another clinical trial that has not reached the follow-up time point to primary endpoint assessment.