[Electrophysiologic basis of the anti-arrhythmic action of amiodarone in man].
The aim of this study was to analyse the effect of an intra-atrial injection of 5 mg/kg of amiodarone on the heart rate, the A-V conducting pathways, and the right atrium and ventricle of 23 patients. By recording the potentials in the bundle of His, it was possible to measure the nodal A-V conduction time (A-H interval) and the conduction time below the bundle of His (H-V interval) during atrial pacemaking. The refractory periods were calculated by the stimulus-test method. The results were subjected to statistical analysis using Student's test. They may be summarised as follows: - slowing of the sinus rhythm; - depressed conduction in the A-V node, but without any effect on the speed of conduction infranodally; - an increase in the atrial effective refractory period; - persistant lengthening of both the effective and the functional refractory periods of the A-V node; - an increase in the relative refractory period in the His-Purkinje system, and in the effective refractory period of the ventricle. These findings throw light on the mechanism of the anti-arrhythmic action of amiodarone in man.
D000200:Action Potentials / Q000187:drug effects; D000293:Adolescent; D000328:Adult; D000368:Aged; D000638:Amiodarone / Q000494:pharmacology* / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D001145:Arrhythmias, Cardiac / Q000188:drug therapy; D001572:Benzofurans / Q000494:pharmacology*; D002036:Bundle of His / Q000187:drug effects; D002986:Clinical Trials as Topic; D003864:Depression, Chemical; D004341:Drug Evaluation; D005260:Female; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D006329:Heart Conduction System / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects*; D006352:Heart Ventricles / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged
D000889:Anti-Arrhythmia Agents; D001572:Benzofurans; D000638:Amiodarone
Bases électrophysiologiques de l'action antiarythmique de l'amiodarone chez l'homme