Effects of chronic, oral amiodarone on left ventricular pressure, electrocardiograms, and action potentials from myocardium in vivo and from Purkinje fibers in vitro.
Left ventricular pressure, electrocardiograms, and action potentials from myocardium and Purkinje fibers were recorded from five untreated controls and five dogs given amiodarone at 25 mg/kg every 12 hours for 4 weeks, followed by 25 mg/kg once daily for an additional 6 weeks. QT interval and action potential duration were more prolonged following treatment with amiodarone, but there were no significant changes in Purkinje fibers except that automaticity was suppressed. This study demonstrated that amiodarone given orally for 10 weeks to healthy dogs lengthens action potential duration of myocardium but has no effect on Purkinje fibers or heart rate variability. This is contrary to previous reports of dogs given amiodarone at a lower dose and for shorter times.
Bicer
S
S
The Ohio State University, College of Veterinary Medicine, Department of Veterinary Biosciences, 1900 Coffey Road, Columbus, OH 43210, USA.
Nakayama
H
H
Nakayama
T
T
Strauch
S M
SM
Hamlin
R L
RL
D000200:Action Potentials / Q000502:physiology*; D000638:Amiodarone / Q000008:administration & dosage* / Q000494:pharmacology*; D000818:Animals; D004285:Dogs; D004334:Drug Administration Schedule / Q000662:veterinary; D004562:Electrocardiography / Q000662:veterinary*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009206:Myocardium; D011690:Purkinje Fibers / Q000187:drug effects*
D000638:Amiodarone