We Evaluated CT-guided Localization of the Right Phrenic Nerve to Enhance Safety in Transcatheter AblationNCT07330791
Right Phrenic Nerve Localization on CT for Ablation
An observational study of We Evaluated CT-guided Localization of the Right Phrenic Nerve to Enhance Safety in Transcatheter Ablation, run by Centro Medico Teknon at 1 site in Spain.
Trial summary
The anatomical location of the right phrenic nerve (RPN) in close proximity to the right pulmonary veins has become a critical consideration for electrophysiologists performing pulmonary vein isolation, the cornerstone treatment for atrial fibrillation. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- We Evaluated CT-guided Localization of the Right Phrenic Nerve to Enhance Safety in Transcatheter Ablation
- How many people
- 80 participants
- Where
- 1 siteSpain
- Study dates
- 1 Apr 2025to 29 Sep 2025
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: All patients underwent an electrocardiography-gated cardiovascular CT using a 64-slice multidetector row CT scanner (Revolution CT, GE Healthcare Global Diagnostic Imaging) prior to the ablation procedure. The position line was set at 0.5 cm below the tracheal bifurcation to the cardiac diaphragmatic surface. The acquisition was performed within a single breath- hold. The gantry rotation time was 0.35 s, and the tube current was 350-750 mA at 120 kV. Iodinated contrast material (60 mL; Omnipaque 300 mg/mL), was injected at a rate of 4-5 mL/s, followed by 20 mL of saline solution. A second acquisition immediately after is performed to study the venous phase. Original images at 75% or 45% R-R intervals were transferred to post-processing Workstation, with a section thickness of 0.625 mm. If motion artifacts appeared, the electrocardiographic editing technique was used and the reconstructed window was moved forward or backward for 5% R-R interval until the motion artifacts disappeared.
Who may be able to join
- Ability to provide informed consent
- Patients who have undergone or will undergo transcatheter AF ablation or CNA
- Availability of 64-slice contrast-enhanced MDCT with RPN segmentation using ADAS® software prior to ablation
- Age ≥ 18 years
Who cannot join
- Inability to provide informed consent
- Inability to perform contrast-enhanced CT before transcatheter AF ablation or CNA
- Age < 18 years
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Right Phrenic Nerve Localization Using CT Scanning: Implications for Radiofrequency Ablation Procedures
The anatomical location of the right phrenic nerve (RPN) in close proximity to the right pulmonary veins has become a critical consideration for electrophysiologists performing pulmonary vein isolation, the cornerstone treatment for atrial fibrillation. Although radiofrequency ablation in this region is rarely associated with complications-unlike cryoballoon ablation-the proximity of the RPN to the ablation site is considered the most widely accepted mechanism of nerve injury. Therefore, accurately defining its anatomical course is essential to prevent complications.
This concern extends to any ablation procedure performed near the RPN, including those targeting the lateral-posterior region of the right atrium, particularly during atrial tachycardia ablation or cardioneuroablation. Several methods have been used to precisely localize the RPN. The most commonly employed technique is phrenic nerve stimulation; however, there is growing interest in the use of computed tomography (CT) to identify structures running parallel to the nerve-such as the pericardiophrenic artery and vein-enhanced with contrast. Three-dimensional reconstruction through image segmentation has proven useful in defining the anatomy of cardiac chambers and adjacent extracardiac structures.
This study aims to compare two approaches for visualizing the course of the right phrenic nerve: one based on computed tomography imaging and the other on the nerve's response to stimulation during the procedure. This comparison will allow us to assess the concordance between imaging findings and intra-procedural observations, ultimately contributing to improved procedural safety.
- Keywords
- Right Phrenic Nerve, Phrenic Nerve Localization, Computed Tomography, CT-Guided Imaging, Radiofrequency Ablation, Catheter Ablation, Transcatheter Ablation Safety, Cardiac Ablation Complications, Ablation Procedures, Phrenic Nerve Injury
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| This study will enroll patients undergoing two distinct types of ablative procedures g | A total of 80 consecutive patients will be included: * 60 patients will be enrolled using a single electric stimulation output set at 20 mA, 2 ms amplitude width and 1000 ms cycle length * 20 patients will be enrolled using a double electric stimulation output set respectively at 10 mA and 20 mA (2 ms amplitude width and 1000 ms cycle length) |
What is being measured
The primary outcome is the main question the study is designed to answer.
analyse the anatomy of the RPN
The primary endpoint of this study is to analyse the anatomy of the RPN using three-dimensional (3D) imaging and iso-distance mapping with ADAS® software, and to validate its accuracy through traditional pace mapping.
Measured: From January 2021 to April 2025
Accuracy of Imaging-Guided Anatomical Localization of the Phrenic Nerve with ADAS® software Compared With Conventional Pacemapping
The positions as observed by the 2 different methods are compared and the correlation was expressed as a percentage. Global image correlation is computed as the mean correlation between methods.
Measured: from the procedure to 12 months later
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Jan 2026
- Study start1 Apr 2025
- Primary completion20 Sep 2025
- Study completion29 Sep 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for We Evaluated CT-guided Localization of the Right Phrenic Nerve to Enhance Safety in Transcatheter AblationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 80 participants (actual)
Sponsor and investigators
- Lead sponsor
- Centro Medico Teknon
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Antonio Berruezo, MD, PhD, Centro Medico Teknon
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07330791
- Sponsor's protocol ID
- Phrenic nerve CT-Localization
- Status last verified
- Sep 2025
- First submitted
- 10 Dec 2025
- Last updated
- 9 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 9 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Right Phrenic Nerve Localization Using CT Scanning: Implications for Radiofrequency Ablation Procedures
- ClinicalTrials.gov ID
- NCT07330791
- Acronym / sponsor ID
- Phrenic nerve CT-Localization
- Keywords
- Right Phrenic Nerve, Phrenic Nerve Localization, Computed Tomography, CT-Guided Imaging, Radiofrequency Ablation, Catheter Ablation, Transcatheter Ablation Safety, Cardiac Ablation Complications
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 80 participants (actual)
- Lead sponsor
- Centro Medico TeknonUniversity, hospital or other
- Study start
- 1 Apr 2025 (actual)
- Primary completion
- 20 Sep 2025 (actual)
- Study completion
- 29 Sep 2025 (actual)
- First posted
- 9 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The anatomical location of the right phrenic nerve (RPN) in close proximity to the right pulmonary veins has become a critical consideration for electrophysiologists performing pulmonary vein isolation, the cornerstone treatment for atrial fibrillation. Although radiofrequency ablation in this region is rarely associated with complications-unlike cryoballoon ablation-the proximity of the RPN to the ablation site is considered the most widely accepted mechanism of nerve injury. Therefore, accurately defining its anatomical course is essential to prevent complications.
This concern extends to any ablation procedure performed near the RPN, including those targeting the lateral-posterior region of the right atrium, particularly during atrial tachycardia ablation or cardioneuroablation. Several methods have been used to precisely localize the RPN. The most commonly employed technique is phrenic nerve stimulation; however, there is growing interest in the use of computed tomography (CT) to identify structures running parallel to the nerve-such as the pericardiophrenic artery and vein-enhanced with contrast. Three-dimensional reconstruction through image segmentation has proven useful in defining the anatomy of cardiac chambers and adjacent extracardiac structures.
This study aims to compare two approaches for visualizing the course of the right phrenic nerve: one based on computed tomography imaging and the other on the nerve's response to stimulation during the procedure. This comparison will allow us to assess the concordance between imaging findings and intra-procedural observations, ultimately contributing to improved procedural safety.
Study design
- Observational model
- Other
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| This study will enroll patients undergoing two distinct types of ablative procedures g | – | –A total of 80 consecutive patients will be included: * 60 patients will be enrolled using a single electric stimulation output set at 20 mA, 2 ms amplitude width and 1000 ms cycle length * 20 patients will be enrolled using a double electric stimulation output set respectively at 10 mA and 20 mA (2 ms amplitude width and 1000 ms cycle length) |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- All patients underwent an electrocardiography-gated cardiovascular CT using a 64-slice multidetector row CT scanner (Revolution CT, GE Healthcare Global Diagnostic Imaging) prior to the ablation procedure. The position line was set at 0.5 cm below the tracheal bifurcation to the cardiac diaphragmatic surface. The acquisition was performed within a single breath- hold. The gantry rotation time was 0.35 s, and the tube current was 350-750 mA at 120 kV. Iodinated contrast material (60 mL; Omnipaque 300 mg/mL), was injected at a rate of 4-5 mL/s, followed by 20 mL of saline solution. A second acquisition immediately after is performed to study the venous phase. Original images at 75% or 45% R-R intervals were transferred to post-processing Workstation, with a section thickness of 0.625 mm. If motion artifacts appeared, the electrocardiographic editing technique was used and the reconstructed window was moved forward or backward for 5% R-R interval until the motion artifacts disappeared.
Key inclusion criteria (4 listed)
- Ability to provide informed consent
- Patients who have undergone or will undergo transcatheter AF ablation or CNA
- Availability of 64-slice contrast-enhanced MDCT with RPN segmentation using ADAS® software prior to ablation
- Age ≥ 18 years
Key exclusion criteria (3 listed)
- Inability to provide informed consent
- Inability to perform contrast-enhanced CT before transcatheter AF ablation or CNA
- Age < 18 years
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
analyse the anatomy of the RPN
Time frame: From January 2021 to April 2025
The primary endpoint of this study is to analyse the anatomy of the RPN using three-dimensional (3D) imaging and iso-distance mapping with ADAS® software, and to validate its accuracy through traditional pace mapping.
Accuracy of Imaging-Guided Anatomical Localization of the Phrenic Nerve with ADAS® software Compared With Conventional Pacemapping
Time frame: from the procedure to 12 months later
The positions as observed by the 2 different methods are compared and the correlation was expressed as a percentage. Global image correlation is computed as the mean correlation between methods.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Jan 2026.
- Individual participant dataSharing planned: Undecided
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of We Evaluated CT-guided Localization of the Right Phrenic Nerve to Enhance Safety in Transcatheter Ablation, run by Centro Medico Teknon at 1 site in Spain.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Spain. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
analyse the anatomy of the RPN (time frame: From January 2021 to April 2025). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Jan 2026.