[Effect of amiodarone on autonomic status and its efficacy in the treatment of different variants of paroxysmal atrial fibrillation].

Association of autonomic status and efficacy of therapy with amiodarone was studied in 90 patients with paroxysmal atrial fibrillation of ischemic (n=45, mean age 62 years) and nonischemic (n=45, mean age 38 years) origin. Autonomic status was assessed by measurement of heart rate variability. Electrophysiological and echocardiographical studies were also conducted before and after 4 weeks of amiodarone therapy. Treatment with amiodarone was accompanied by substantial lowering of the tone of autonomic nervous system in patients with adrenergic type of paroxysmal atrial fibrillation while there was no dynamics of parasympathetic tone in patients with vagal or mixed types. Positive association between amiodarone therapy and decrease of left atrial dimension and improvement of left ventricular contractility was also observed. It was concluded that the use of amiodarone was justified in adrenergic but not in vagal or mixed variants of paroxysmal atrial fibrillation.