NCT04041778Completed
'Understanding the Electrophysiological Substrate Underlying Persistent Atrial Fibrillation Study II (USURP AF- Study II)'
Understanding the Electrophysiological Substrate Underlying Persistent Atrial Fibrillation Study II (USURP AF- Study II)'
Source: ClinicalTrials.gov · Last updated 1 Oct 2025
Brief summary (registry, in English)
Atrial fibrillation (AF) is the most common type of chronic heart rhythm disease worldwide, with significant associated co-morbidities. Although there have been advances in understanding the mechanisms of AF, the underlying cause of AF and factors which perpetuate it remain incompletely understood. This is particularly the case for persistent AF (persAF). Drug treatments for persAF have a role but can have undesirable side effects with relatively limited efficacy. Furthermore, current invasive therapies for persAF remain suboptimal, requiring significant resources, and with potentially serious complications for patients. Catheter ablation is an effective treatment for paroxysmal AF. For persistent AF (persAF), however, catheter ablation does not provide similar results. This is because there remains a poor understanding of the electrophysiological mechanisms driving persAF. Part of this study aims to further explore the specific locations that represent important substrates which would guide more effective catheter ablation. There have been several different ablation approaches explored in the past (see below), however, these did not improve the outcome post procedure compared with pulmonary vein isolation alone. A pilot study has already been carried out and I aim to expand this further with a larger cohort of patients (10-20) over 2 years. In this study the investigators want to explore whether stable high dominant frequency (HDF) sites (with a high organisation index) act as potential drivers of Atrial Fibrillation. Thus, targeting these sites may results in prolongation of the cycle length and thus possible termination of the arrhythmia.
- Status (registry)
- Completed
- Study type
- Observational
- Enrollment
- 17 (actual)
- First submitted
- 29 Jul 2019
- Start date
- 25 Jul 2019
- Primary completion date
- 30 Sept 2024
- Lead sponsor
- University of Leicester
- Diseases
- Atrial fibrillation
- NCT number
- NCT04041778
What you commit to
- Study type: Observational
- Participants enrolled: 17
- From 25 Jul 2019 to the primary completion date, 30 Sept 2024
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- Previous history of a cardiac arrhythmia (other than AF, atrial tachycardia, atrial flutter).
- Previous cardiothoracic surgery
Other illness
- Symptoms secondary to ischaemic or valvular heart disease
- Congenital heart disease
- Underlying severe respiratory disease (i.e. patient on long term oxygen therapy)
- Medical conditions which will affect cardiac rhythm, even if treated (e.g. thyroxine, etc.)
- Presence of implantable cardiac defibrillator or pacemaker (including cardiac resynchronisation devices).
Other
- Presence of chest deformity.
- Left atrial dilatation (L or R atrial end-diastolic dimension \> 4.5cm in any conventional plane of measurement on 2D transthoracic echocardiography).
Who the study is looking for
- Must be aged 18 years or over
- Must be able to communicate in written and spoken English
- Must be able to give signed informed consent.
- All patients must be defined as having persistent atrial fibrillation (AF \> 7 days) and must be in AF at the start of the procedure.
- The patient preferably should be undergoing AF ablation for the first time, however repeat ablations can be permitted.
- The patient must be listed for persistent AF ablation as part of standard clinical care.
Age in the registry: 18 years to - · Sex: All · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| University Hospitals Leicester NHS Foundation Trust, Glenfield Hospital Coordinator of this site? Confirm its status | Leicester | United Kingdom | Unknown status |
This page is information, not medical advice. Discuss any trial with your doctor.