Background: Atrial fibrillation (AF) remains a significant contributor to cardiovascular morbidity. Amiodarone is a potent antiarrhythmic drug. The safety and efficacy of oral versus intravenous (i.v.) Amiodarone in the treatment of AF of recent onset (duration <48 h) was investigated.
Methods: The study population consisted of 223 patients with symptomatic AF, of whom 110 received 600 mg oral Amiodarone (Group A) in three divided doses and 113 received i.v. Amiodarone (5 mg/kg over 30 min followed by 1000 mg over the next 24 h) (Group B). Digoxin was administered to all patients, who had not previously received it. All patients were monitored for 24 h.
Results: Conversion to sinus rhythm occurred in 85.45% of group A and 82.30% in group B (p=NS). Mean time of cardioversion in group A was 20+/-4.5 h and in group B was 12+/-8 h (p<0,001). However, blood pressure (BP) in group A remained stable for the observation period, whereas it fell significantly in group B. Treatment was not discontinued in any of the patients in either group, however 13 patients in group B developed superficial phlebitis.
Conclusions: Both forms of the drug are extremely efficient in restoring sinus rhythm in AF of recent onset, although the i.v. form acts quicker. The oral form of the drug does not alter significantly the patients' BP.