Atrial fibrillation (AF) remains a significant contributor to cardiovascular morbidity. Amiodarone is a potent antiarrhythmic drug; however, patients receiving IV amiodarone are at high risk for phlebitis. Phlebitis may lead to infection, additional medical intervention, delay in treatment, and prolonged hospitalization. Therefore, examining new therapy approach, aimed to reduce the incidence of phlebitis is a valuable clinical and research goal.

Aim: To evaluate the safety and efficacy of oral versus intravenous (IV) Amiodarone in the treatment of AF of recent onset (duration < 48 h).

Atrial fibrillation (AF) is the most common heart rhythm abnormality worldwide. Three therapeutic goals should be considered for each patient: Rate control, maintenance of sinus rhythm and prevention of thromboembolism. In managing AF, numerous antiarrhythmic drugs have been used. Intravenous amiodarone is a class III antiarrhythmic agent which has been reported to be safe and most effective in various clinical settings, without an associated increase in mortality rate. In most of the cases, the method of administration is via peripheral infusion. Phlebitis is the most common complication with peripheral infusion of amiodarone. Phlebitis adversely affects patient care; it may interfere with the continued infusion of amiodarone, necessitate insertion of another peripheral intravenous or central catheter, and extend hospitalization. Furthermore, patients who develop phlebitis, experience pain, swelling, and inflammation. Phlebitis can be prevented by oral administration.

The goal of the proposed study is to evaluate the incidence rate of phlebitis following IV administration of amiodarone and to investigate whether the oral administration of amiodarone in patients with recent onset AF (duration < 48 h), is safer than, and as efficient as, the IV administration of the same drug in the ICCU and ICU setting.

Inclusion Criteria:

• Over 18 years of age,
• Patients who will be admitted to the ICCU / ICU wards
• Patients with recent onset of atrial fibrillation (duration < 48h).

Exclusion Criteria:

• Age < 18 years
• Baseline systolic blood pressure < 100 mm/hg
• Known thyroid disease
• Serum potassium < 3.5 mmol/l
• Pretreatment with amiodarone
• Pregnant or lactating women.
• Participation in other clinical trial.