Objectives To investigate the efficacy and safety of the low dose oral amiodarone therapy in patients for the long-term prevention of paroxysmal atrial fibrillation (PAF).
Methods Usage of Amiodarone After conversion by using medicine or electroversion or spontaneous conversion, a initial dose of amiodarone was given within 2 weeks as follows, 0.2 g for three times a day for the first week and then 0.2 g for two times a day during the second week. The maintenance dose of amiodarone (0.1–0.2 g for one time a day) was administered from the third week.
Results Sixty-two consecutive patients with PAF were followed up after amiodarone was orally administered. The mean duration of follow-up was 16.3±8.3 (1–24) years. 6 months, 12 months and 24 months after amiodarone treatment. The clinical effective rate was 86.44%, 75.86%, 59.0% and 73.3% respectively. No patient had significant side effects. The univariate analysis demonstrated that there were differences on the sides included age (≥65 years old) and coronary heart disease in the 2 groups (U=230.500, p=0.006; X2=6.651, p=0.010). Through Logistic regression analysis, age (≥65 years old) and coronary heart disease were confirmed not to be independent risk factors for the efficacy of amiodarone therapy (OR=4.060, p=4.060; OR=0.355, p=0.196).There were 14 cases (22.95%) with sinus bradycardia, among them, four cases stop taking them and three cases install heart pacemakers, but no case occur serious arrhythmia or Cardiac dysfunction worse and angina symptoms. There were 12 cases with abnormal thyroid function, among them 7 case (11.48%) with Hypothyroidism. No severe side effects were observed in other cases.
Conclusions Amiodarone may provide an effective and relatively safety therapeutic approach to maintaining sinus rhythm in patients with paroxysmal atrial fibrillayion. The adverse drug reactions of amiodarone should be observed during the medication period. There were no evidence suggest age (≥65 years old), heart function classification, left atrium diameter, IBM body mass index, the history of PAF, ACEI and ARB, coronary heart disease, were confirmed not to be independent risk factors for the efficacy of amiodarone therapy.