Use of Omega 3 Polyunsaturated Fatty Acids Supplements to Maintain Sinus Rhythm in Persistent Atrial Fibrillation

The patients. Randomisation. Patients with persistent AF will be recruited from clinic attendees and in-patient hospital patients at Ninewells Hospital and Medical School. A total of 150 patients with AF of more than 7 days duration and scheduled for elective direct current cardioversion will be recruited. The patients will be randomised to receive fish oil supplements (3g/day) or placebo on recruitment for a period of 4 weeks prior to cardioversion and continued after cardioversion until recurrence of AF or until the end of 6 months. All patients will be anticoagulated routinely. Patients on anti-arrhythmic drugs, left atrial size >6 cm, significant mitral valve disease, myocardial infarction in the last 3 months, unstable angina, NYHA IV heart failure, cardiac surgery in the previous 3 months, acute reversible conditions, significant thyroid, hepatic, pulmonary disease, pregnancy or child bearing potential will be excluded from the study.

3.2. End Points of the Study. The primary endpoint will be time to first electrocardiographically confirmed recurrence of atrial fibrillation/flutter lasting more than 10 minutes. Secondary endpoints will be shock number and energy requirements to achieve electrical cardioversion. All patients will give informed consent and approval will be obtained from the Ethics Committee of Ninewells Hospital and Medical School.

3.3. Free n-3 PUFA plasma concentrations On the day of cardioversion, 3mls of venous blood will be obtained for measurement of free n-3 PUFA plasma concentrations.

3.4. Elective Direct current cardioversion and Follow-up Patients will be routinely scheduled for cardioversion (2 per week) as outpatients. Cardioversion will be under conscious sedation (titrated doses of intravenous midazolam) as is the current routine practice in the Department of Cardiology, Ninewells Hospital. Follow-up (with ECG) of cardioverted patients will be weekly in the first month; then 2,3,4,5 and 6 months; and at any time the patients complains of palpitations or other symptoms.