title: [On the possibility of amiodarone use in some cases of persistent atrial fibrillation].
abstract: Aim of the study was to investigate mechanisms of amiodarone action on atrial and ventricular rhythm during persistent atrial fibrillation (PAF), and to assess efficacy of amiodarone as monotherapy or in combination with digoxin. Holter ECG monitoring and registration of high resolution ECG with construction of periodograms of ff waves and histograms of RR intervals (MATLAB 5.3 environment) were carried out in 34 patients (mean age 63.1+/-11.0 years) with PAF. Amiodarone (550.0+/-143.4 mg/day), digoxin (0.30+/-0.09 mg/day) with amiodarone (571.4+/-106.9 mg/day) were given for 21 days with recordings of high resolution ECG at baseline and on day 21. Long term therapy (1.7 years) with combination of digoxin 0.19+/- 0.07 mg/day) and amiodarone (254+/-82.0 mg/day) was controlled by Holter ECG monitoring. Monotherapy with amiodarone was not associated with significant lowering of heart rate (HR) (small er, Cyrillic=0.054) because of complex effect of amiodarone of HR: significant increase of period of ff waves (by 0.031+/-0.011 s), with facilitation of their conduction to ventricles combined with significant 0.10+/-0.08 s increment of minimal RR. Amiodarone combined with digoxin caused significantly lesser (by 0.009+/-0.017 s) enlargement of ff waves and significant lowering of HR (by 21.24+/-15.77 bpm) at the account of slowing of AV conduction (minimal RR increased by 0.12+/-0.08 s) and suppression of early RR peaks (0.28-0.46 s). The combination effectively suppressed tachysystolia resistant to other therapy (maximal HR 170-215 bpm) with significant lowering of mean (by 16.5+/-13.1 bpm) and maximal (by 43.3+/-35.6 s) HR, with suppression of ventricular extrasystoles in 83% of patients, and without significant lowering of minimal HR and appearance of pauses from 3 s. Level of thyrotrophic hormone rose from 2.4 to 5/9 IU/ml (p >0.05).
authors.forename: O V
authors.initials: OV
authors.lastname: Blagova
authors.forename: A V
authors.initials: AV
authors.lastname: Nedostup
mesh_terms: D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000494:pharmacology* / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology* / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy* / Q000503:physiopathology; D004077:Digoxin / Q000627:therapeutic use; D004359:Drug Therapy, Combination; D004562:Electrocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D016276:Ventricular Function / Q000187:drug effects
chemical_list: D000889:Anti-Arrhythmia Agents; D004077:Digoxin; D000638:Amiodarone