Beat-to-beat Variability in Persistent Atrial Fibrillation

Beat-to-beat Variability in Persistent Atrial Fibrillation

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.

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.