An interventional study of Electrode tissue contact assessment during pulsed field ablation in Atrial Fibrillation (AF), sponsored by University Medical Centre Ljubljana. Not yet recruiting at 1 site in Slovenia. Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-10-22.
Sponsored by University Medical Centre Ljubljana · Not applicable, Interventional, and Treatment
Pulmonary vein isolation remains the cornerstone of invasive treatment for atrial fibrlllation. Despite recent technological advances in the field of pulsed field ablation (PFA) pulmonary vein isolation durability and arrhythmia free success rates remain approximately at the level of previous years and the radiofrequency ablation era.
Isolation durability during PFA procedures might be enhanced by:
The aim of our study is to use intracardiac electrogram (iEGM) based analysis for assessment of catheter-tissue contact and PFA lesion durability.
Study design: single group, prospective, observational study. Inclusion criteria and eligibility: patients with paroxysmal atrial fibrillation referred to our center for catheter ablation in accordance with EHRA guidelines and with signed written consent for participation in the study.
Study group: 60 patients divided in two groups. Group 1: initial 10 patients that will have the PFA procedure performed as is stated under Group 1 in the Procedural Protocol section.
Group 2: next 50 patients that will have procedural protocol defined after analysis of procedures in the initial 10 patients.
Procedural protocol:
all patients will have a contrast enhanced computer tomography (CTA) scan of the left atrium performed before the ablation procedure. CTA based left atrial 3D reconstruction will be created with a dedicated segmentation software and fused with the 3D model of the left atrium created during the procedure using the 3D electroanatomical mapping (EAM) system.
Procedures will be performed in deep sedation, using 3D EAM system and intracardiac echocardiography. PFA applications per vein and per antrum will be delivered as specified and recommended by Medtronic. After full lesion set high density mapping of pulmonary veins, venous ostia and antral regions for signs of acute conduction gaps and residual (dormant) conduction within isolation lines will be performed.
Group 1: will include the first 10 patients. First PFA applications per side (left or right) will be delivered in a manual mode (4 manual applications per one full set). An intracardiac electrocardiogram (iEGM) recording period of 30 seconds will be used before the start of applications and a 2 minute iEGM recording period will be used after each of the 4 manual applications with the ablation catheter left in place during the recording. After the first application on each side, applications will be switched to automatic mode and a iEGM recording period of 2 minutes will be used after each automatic application with 30 seconds recording used as the baseline. Recording will include bipolar and unipolar iEGMs. Total number of applications will 32, 4 ostial and 4 antral per vein.
Group 2: will include additional 50 patients. Mode of iEMG recording (bipolar, unipolar, filter settings) and recording time will differ from Group 1 and will be specified based on analysis and correlation of iEGM recordings with acute and longterm conduction gaps.
In this group additional PFA applications will be delivered at ostial/antral regions that will harbor potentially insufficient (nontransmural irreversible electroporation) lesions according to analysis and correlation of iEGM recordings with acute and longterm conduction gaps.
Follow-up (Group 1 and 2) At 6-8 weeks after the procedure all patients will undergo a mandatory reassessment procedure with high density mapping of veins, venous ostia and antral regions for signs of longterm conduction gaps. Any conduction gaps and residual (dormant) conduction within isolation lines will be recorded and tagged on the 3D EAM maps.
Patients will be followed at the outpatient clinic at 3, 6 and 12 months with 7-day holter ECG recordings at each visit.
Outcome measures
Study will be conducted in two phases
Phase 1 (duration 1 year):
Obtaining approval of Medical ethics committee Enrolment of 10 patients (group 1) with remap at 6-8 weeks
Phase 2 (duration 2 years) with 1 year follow-up in an out-patient clinic using 7-day holter ECG recordings at 3, 6 and 12 months
4,009 studies on the registry are indexed under Atrial Fibrillation; 961 are open to participants now.
This study's planned enrollment of 60 is below the median of 150 across 2,476 interventional studies indexed under Atrial Fibrillation.
Browse Atrial Fibrillation studies →University Medical Centre Ljubljana is the lead sponsor of 296 studies on the registry; 72 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
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Assessment of contact between electrodes on the pulsed field ablation (PFA) catheter and left atrial wall will be made based on change of bipolar intracardiac electrograms (iEGM) after first PFA delivery.
Device: Electrode tissue contact assessment during pulsed field ablation
Pulsed field ablation (PFA) catheter electrode - tissue contact assessment based on analysis of bipolar intracardiac electrocardiograms: a multipolar PFA catheter will be used for pulmonary vein isolation in a manual mode, which means that instead of delivering fully therapeutic four ablative high voltage pulse trains at each location around pulmonary veins, each of those pulse trains will be delivered manually. Changes (voltage, shape,...) in bipolar intracardiac electrocardiograms (iEGM) measured with ablative catheter electrodes will be assessed after each manual pulse train delivery.
Assessment of contact
Assessment of contact (electrode - tissue) based on analysis of intraprocedural characteristics and acute changes of bipolar iEGMs: when bipolar iEGM voltage amplitude will decrease significantly after first manual ablative pulse train delivery the contact will be considered as good, in contrast to no or minimal change in bipolar iEGM amplitude when contact will be considered as poor.
Time frame: During index procedure.
Assessment of PFA lesion durability
Assessment of PFA lesion durability based on analysis of intraprocedural characteristics and changes of unipolar intracardiac electrocardiograms (iEGM). Additionally to bipolar iEGM changes during index procedure for used for contact assessment also the unipolar iEGM changes will be followed with an assumption that prolonged and unchanged increased unipolar iEGM amplitude after PFA delivery at each location correlates with transmural PFA lesion formation that leads to durable ablation lesions and durable pulmonary vein isolation.This durability of ablation lesions and pulmonary vein isolation will be assessed at mandatory reassessment procedures (remapping procedures with a high-density mapping catheter).
Time frame: From index procedure until 6-8 week mandatory reassessment procedure.
Recurrence of arrhythmia
Recurrence based on registration of 30 second or longer episodes of atrial fibrillation/atrial flutter/atrial tachycardia on 7-day holter electrocardiogram or arrhythmia recorded on 12-lead surface electrocardiogram at 3, 6 and 12 monthy after index procedure. If available, additional symptom driven holter ECG or 12-lead electrocardiogram recordings will be used for analysis.
Time frame: From index procedure until completed 12 month follow-up.
Plan to share: Yes — IPD used in results for publication.
Supporting information: Study protocol, Statistical analysis plan, Clinical study report
Time frame: 1.9.2026-1.9.2028
Access criteria: Upon request with a proposal that describes planned analyses and anticipated results. Request must be made directly to the Principal investigator using contact information. Requests will be reviewed by the Principal investigator and Study chair.
No publications or documents are linked to this record.
Start is estimated for Dec 2026; primary completion for Dec 2028, 24 months later.
Of 796 non-industry interventional studies with no phase under Atrial Fibrillation, half reached primary completion within 40 months of starting (the median), counting those still running; a quarter within 21 and three quarters within 59. This study's planned 24 months is below that.
Counting every sponsor, half of 1,051 studies reached it within 33 months; a quarter within 18 and three quarters within 54.
Since we started tracking on Sep 25, 2026, the dates moved once, on Oct 22, 2026: start Sep 2026 → Dec 2026, primary completion Sep 2028 → Dec 2028 and completion Sep 2028 → Dec 2028.
Earlier changes are on the record history on ClinicalTrials.gov ↗
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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