An interventional study of Catheter ablation and Deep sedation with midazolam and fentanyl or midazolam and remifentanil in Atrial Fibrillation (AF), sponsored by East Sussex Healthcare NHS Trust. Recruiting at 1 site in United Kingdom. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-28.
Sponsored by East Sussex Healthcare NHS Trust · Not applicable, Interventional, and Treatment
Pulsed Field Ablation (PFA) has created a 'paradigm shift' within cardiac electrophysiology and the initial experience demonstrates that PFA is safe, rapid and effective compared to both radiofrequency ablation and cryoablation in atrial fibrillation (AF). Presently, AF ablation procedures in the UK using PFA are routinely performed using general anaesthetic (GA) support requiring an anaesthetist and ODP being present in all procedures. This need significantly limits the ability to use PFA technology to perform AF ablations, particularly in centres that have limited availability of GA provision.
The need for GA also leads to extended patient recovery time post procedure which impacts patient throughput and has the potential to reduce hospital bed availability. The need for GA and the potential to limit patient throughput has negative implications for all hospitals in terms of cost. PFA procedures performed elsewhere in Europe use deep sedation with IV propofol led by the ablating physician, but this is not permitted in the UK and still requires the presence of an anaesthetist.
The investigators will aim to evaluate if AF ablation using PFA is feasible during spontaneous respiration without the use of propofol. The investigators will conduct a non-randomized study comparing AF ablation using PFA vs cryoballoon under deep sedation - aiming to demonstrate that >75% of patients can complete the PFA protocol under deep sedation without conversion to cryoballoon (due to patient intolerance). The principal aim of the study is therefore not to demonstrate superiority or comparative efficacy of one ablation modality over another but rather the ability and feasibility to deliver pulsed field ablation under deep sedation. The use of cryoablation serves as a benchmark comparator to contextualise procedural and sedation-related observations.
60 patients undergoing a clinically-indicated AF ablation procedure will be allocated in a 2:1 ratio to either receive PFA or cryoballoon. All procedures will be completed using deep sedation using intravenous fentanyl or remifentanil infusion and midazolam. Additionally, a bolus of intravenous lidocaine will be given to suppress the cough reflex during PFA applications. If a participant is unable to tolerate the procedure using PFA, the procedure will be converted to cryoballoon during the same sitting and completed as per standard clinical protocol. It is anticipated that general anaesthesia will not be required for any participants in the study.
If the study proves successful, this will provide a clear deep sedation protocol for use with PFA during pulmonary vein isolation with a view to reducing the need for GA cover and improve lab efficiency which has significant financial implications for NHS healthcare providers.
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 →This is the only study on the registry with East Sussex Healthcare NHS Trust as lead sponsor.
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Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Device: Catheter ablation · Drug: Deep sedation with midazolam and fentanyl or midazolam and remifentanil
Device: Catheter ablation · Drug: Sedation with midazolam and fentanyl
Catheter ablation for AF
During ablation, sedation will be given with either midazolam and fentanyl or midazolam and remifentanil
Drug pages: Midazolam · Fentanyl
Sedation using lower doses of midazolam and fentanyl
Percentage of patients able to complete protocol with pulsed field ablation without conversion to cryoablaton
Target is 75% of patients
Time frame: 18 months
Numeric Rating scale for pain - Pain severity index (PSI)
0-10 (high score = more pain) - comparison of pain scores between PFA and cryoablation
Time frame: 18 months
- Patient Experience Questionnaire for post-procedural pain, discomfort - Visual Analogue Scale (VAS) - Atrial Fibrillation Specific Patient Reported Outcome Measures Questionnaire (AF-PROMs) questionnaire
Patients mark with an X on a visual analogue scale how much pain/discomfort they experienced (0-10) - 10 being more pain; comparison of numerical scores between pulsed field ablation and cryoablation
Time frame: 18 months
- Lab occupancy time/ skin-to-skin time
Time in minutes
Time frame: 18 months
Plan to share: No
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