An observational study in We Evaluated CT-guided Localization of the Right Phrenic Nerve to Enhance Safety in Transcatheter Ablation, sponsored by Centro Medico Teknon. Completed at 1 site in Spain. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-01-09.
Sponsored by Centro Medico Teknon · Observational
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.
Centro Medico Teknon is the lead sponsor of 20 studies on the registry; 11 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Exclusion Criteria:
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)
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.
Time frame: 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.
Time frame: from the procedure to 12 months later
Plan to share: Undecided
No publications or documents are linked to this record.
This study is completed, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Centro Medico Teknon