Beat-to-beat Variability in Persistent Atrial Fibrillation

Study Overview
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Brief Summary
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Heart rate variability (HRV) in patients with atrial fibrillation (AF) is hardly studied. Though a reduced HRV in patients with heart failure and reduced ejection fraction (HFrEF) has been associated with poor prognosis. Data on HRV in AF-patients without a reduced ejection fraction is lacking. We hypothesize that those patients with persistent atrial fibrillation and larger beat-to-beat variability would be more symptomatic than does those with smaller HRV. To asses this theory we intend to perform a prospective observational trial. Symptoms of Atrial fibrillation will be assessed using Quality of Life questionnaires and 6 minutes walking test. Heart rate variability will be assessed using 24 hour Holter ECG monitoring. The correlation between symptoms and heart rate variability will be then assessed.

Official Title
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Beat-to-beat Variability in Persistent Atrial Fibrillation

Conditions
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Persistent Atrial Fibrillation

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Persistent atrial fibrillation No previous ablation for atrial fibrillation At least 18 years old Signed written patient's informed consent Exclusion Criteria: Paroxysmal atrial fibrillation Previous ablation therapy for atrial fibrillation Reduced left ventricular ejection fraction (LVEF<35%) Permanent ventricular pacing (including cardiac resynchronization therapy CRT) Acute coronary syndrome (ACS) during past 6 weeks. Stroke or TIA within past 6 weeks. Cardiac surgical operation/ intervention within past 3 months. Acute decompensated heart failure Treatment with IV Inotropic medications (e.g. Dobutamine, Levosimendan) Mitral valve replacement or rheumatic mitral valve stenosis Neurological or psychological disease that may impair patient's judgement or compliance Pregnancy or Breast-feeding women.

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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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Atrial fibrillation symptoms | Whether atrial fibrillation symptoms assessed by Quality-of-Life questionnaires correlates with heart rate variability | 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Atrial fibrillation symptoms | Whether atrial fibrillation symptoms assessed by Quality-of-Life questionnaires correlates with heart rate reserve. Heart rate reserve is defined as the difference between maximal heart rate (220- age in years) and mean heart rate during atrial fibrillation (assessed by 24 hour Holter ECG monitoring). | 7 days | 
| Improvement in 6MWD (6 minutes walk distance) | Whether 6MWD improvement after treatment of atrial fibrillation correlates with heart rate variability. | 7 days | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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persistent atrial fibrillation, Heart rate variability, quality of life