Exploring P-Wave Duration in Arrhythmia Recurrence in Patients Undergoing AF Ablation

Study Overview
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Brief Summary
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The aim of this study is to investigate whether P-wave duration in a baseline surface 12-lead ECGs correlates with recurrence of AF recurrence post successful ablation at the time of the procedure.

Detailed Description
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Patients with paroxysmal AF are often treated arrhythmia-free (75%) with a single catheter ablation at 12 months post procedure . In contrast, in patients with persistent AF or long persistent AF, catheter ablation is more complex and often yields in lower success rates of around 50% often requiring multiple attempts . The success rates remain low despite several different ablation sites having been proposed (additional lines plus PVI, epicardial approach). There is growing evidence that PWD is associated with the extent of left atrial scarring and this can be used a potential predictor of AF recurrence . Moreover, results from the investigators group has previously shown that PWD correlated with the duration of the AF and this could be altered by extensive ablation . It is uncertain whether PWD prior to any procedure for persistent AF, long persistent or paroxysmal AF can accurately predict failure of procedure. This is a single centre observational study of persistent, long persistent and paroxysmal AF population who have undergo AF cryoablation in University Hospital Plymouth . All patients receive this current procedure as standard of care. This study does not involve any patient contact out of the standard routine clinical follow up and therefore no public involvement has been sought.

Official Title
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Exploring the Relationship Between Duration of the Amplified P-Wave Arrhythmia and Recurrence in Patients With Persistent, Long Persistent or Paroxysmal AF Undergoing Cryoablation

Conditions
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Atrial Fibrillation Recurrent

Intervention / Treatment
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* Diagnostic Test: P-wave duration measurement on 12 lead ECG with standard parameters


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with persistent, long persistent or paroxysmal AF undergone AF cryoablation from 2016 onwards Age >18 Patient does not meet exclusion criteria - Exclusion Criteria: Patients whose records cannot be obtained Patients with persistent, long persistent or paroxysmal AF undergone AF ablation prior to 2016 Patients with no documented ECG in sinus rhythm prior to ablation Patients not undergoing cryoablation for AF -

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Diagnostic Test: P-wave duration measurement on 12 lead ECG with standard parameters|Hospital records will be used in order to obtain baseline characteristics and the most recent 12-lead ECG in sinus rhythm prior to ablation will be used to calculate PWD. Measurement of the PWD will be obtained at standard surface ECG recording settings of 25mm/s and 10mm/mV and measured accordingly to our previous protocol. In brief, all ECGs obtained will subsequently be anonymised and randomised by an Independent Clinical Investigator (ICI) before measured by the main clinical investigators blinded to initial results. If a dispute of the measurements arouse, consensus will be used to resolve it after consulting the Chief Investigator (CI) blinded to the results. Bland-Altman plots to minimise bias will be used|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Recurrence of atrial fibrillation. | Primary.This will be documented in a 12 lead ECG >30sec post ablation according to standard operation procedures follow up. Patients are actively followed up in regular intervals (4-12-24 months) post procedure and are able to contact department for advise if clinically suspected recurrence of atrial fibrillation. This is well studied and documented in previous studies as an outcome of measure. | 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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P-wave duration, AF, cryoablation