Abstract
1. The effects of long-term administration of oral amiodarone on transmembrane action potential and contraction of ventricular muscle were investigated in rabbits. 2. ECGs of rabbits that received oral amiodarone 50 mg or 100 mg kg-1 daily for 4 weeks, showed a significant prolongation of RR, QT and corrected QT (QTc) intervals, whereas PQ and QRS were unaffected. Serum and myocardial tissue amiodarone concentrations were 0.14-0.18 micrograms ml-1 and 1.47-3.63 micrograms g-1 wet wt. respectively. 3. Right ventricular papillary muscles isolated from treated rabbits were characterized by a moderate prolongation of action potential duration (APD) compared with controls. A slight decrease of the maximum upstroke velocity (Vmax) was also observed at the higher dose. The APD prolongation by chronic amiodarone, unlike acute effects of sotalol, E-4031, Cs+ and 4-aminopyridine, did not show marked reverse use-dependence. 4. APD and Vmax restitution following slow basic stimuli (0.03 Hz) were unaffected by chronic treatment with amiodarone. 5. Acute application of amiodarone (10 microM) caused a significant decrease in APD and developed tension, as well as a marked use-dependent Vmax inhibition with fast recovery kinetics. 6. These findings suggest that a major and consistent electro-physiological effect of chronic amiodarone is repolarization delay (Class-III action) showing minimal frequency-dependence. However, when amiodarone above a certain concentration is present in the extracellular space, a fast kinetic Class-I action would be added as an acute effect.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Anderson K. P., Walker R., Dustman T., Lux R. L., Ershler P. R., Kates R. E., Urie P. M. Rate-related electrophysiologic effects of long-term administration of amiodarone on canine ventricular myocardium in vivo. Circulation. 1989 Apr;79(4):948–958. doi: 10.1161/01.cir.79.4.948. [DOI] [PubMed] [Google Scholar]
- Balser J. R., Bennett P. B., Hondeghem L. M., Roden D. M. Suppression of time-dependent outward current in guinea pig ventricular myocytes. Actions of quinidine and amiodarone. Circ Res. 1991 Aug;69(2):519–529. doi: 10.1161/01.res.69.2.519. [DOI] [PubMed] [Google Scholar]
- Brien J. F., Jimmo S., Armstrong P. W. Rapid high-performance liquid chromatographic analysis of amiodarone and N-desethyl-amiodarone in serum. Can J Physiol Pharmacol. 1983 Mar;61(3):245–248. doi: 10.1139/y83-038. [DOI] [PubMed] [Google Scholar]
- Cascio W. E., Woelfel A., Knisley S. B., Buchanan J. W., Jr, Foster J. R., Gettes L. S. Use dependence of amiodarone during the sinus tachycardia of exercise in coronary artery disease. Am J Cardiol. 1988 May 1;61(13):1042–1045. doi: 10.1016/0002-9149(88)90122-1. [DOI] [PubMed] [Google Scholar]
- Colatsky T. J., Follmer C. H., Starmer C. F. Channel specificity in antiarrhythmic drug action. Mechanism of potassium channel block and its role in suppressing and aggravating cardiac arrhythmias. Circulation. 1990 Dec;82(6):2235–2242. doi: 10.1161/01.cir.82.6.2235. [DOI] [PubMed] [Google Scholar]
- Follmer C. H., Aomine M., Yeh J. Z., Singer D. H. Amiodarone-induced block of sodium current in isolated cardiac cells. J Pharmacol Exp Ther. 1987 Oct;243(1):187–194. [PubMed] [Google Scholar]
- GIBBS C. L., JOHNSON E. A. Effect of changes in frequency of stimulation upon rabbit ventricular action potential. Circ Res. 1961 Jan;9:165–170. doi: 10.1161/01.res.9.1.165. [DOI] [PubMed] [Google Scholar]
- Gallagher J. D., Bianchi J., Gessman L. J. A comparison of the electrophysiologic effects of acute and chronic amiodarone administration on canine Purkinje fibers. J Cardiovasc Pharmacol. 1989 May;13(5):723–729. [PubMed] [Google Scholar]
- Harris L., McKenna W. J., Rowland E., Holt D. W., Storey G. C., Krikler D. M. Side effects of long-term amiodarone therapy. Circulation. 1983 Jan;67(1):45–51. doi: 10.1161/01.cir.67.1.45. [DOI] [PubMed] [Google Scholar]
- Heger J. J., Prystowsky E. N., Miles W. M., Zipes D. P. Clinical use and pharmacology of amiodarone. Med Clin North Am. 1984 Sep;68(5):1339–1366. doi: 10.1016/s0025-7125(16)31098-7. [DOI] [PubMed] [Google Scholar]
- Hiraoka M., Kawano S. Calcium-sensitive and insensitive transient outward current in rabbit ventricular myocytes. J Physiol. 1989 Mar;410:187–212. doi: 10.1113/jphysiol.1989.sp017528. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hiraoka M., Kawano S. Mechanism of increased amplitude and duration of the plateau with sudden shortening of diastolic intervals in rabbit ventricular cells. Circ Res. 1987 Jan;60(1):14–26. doi: 10.1161/01.res.60.1.14. [DOI] [PubMed] [Google Scholar]
- Hondeghem L. M., Snyders D. J. Class III antiarrhythmic agents have a lot of potential but a long way to go. Reduced effectiveness and dangers of reverse use dependence. Circulation. 1990 Feb;81(2):686–690. doi: 10.1161/01.cir.81.2.686. [DOI] [PubMed] [Google Scholar]
- Honjo H., Kodama I., Kamiya K., Toyama J. Block of cardiac sodium channels by amiodarone studied by using Vmax of action potential in single ventricular myocytes. Br J Pharmacol. 1991 Mar;102(3):651–656. doi: 10.1111/j.1476-5381.1991.tb12228.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ikeda N., Nademanee K., Kannan R., Singh B. N. Electrophysiologic effects of amiodarone: experimental and clinical observation relative to serum and tissue drug concentrations. Am Heart J. 1984 Oct;108(4 Pt 1):890–898. doi: 10.1016/0002-8703(84)90451-4. [DOI] [PubMed] [Google Scholar]
- Kato R., Venkatesh N., Kamiya K., Yabek S., Kannan R., Singh B. N. Electrophysiologic effects of desethylamiodarone, an active metabolite of amiodarone: comparison with amiodarone during chronic administration in rabbits. Am Heart J. 1988 Feb;115(2):351–359. doi: 10.1016/0002-8703(88)90481-4. [DOI] [PubMed] [Google Scholar]
- Kentish J. C., Boyett M. R. A simple electronic circuit for monitoring changes in the duration of the action potential. Pflugers Arch. 1983 Aug;398(3):233–235. doi: 10.1007/BF00657157. [DOI] [PubMed] [Google Scholar]
- Kohlhardt M., Fichtner H. Block of single cardiac Na+ channels by antiarrhythmic drugs: the effect of amiodarone, propafenone and diprafenone. J Membr Biol. 1988 May;102(2):105–119. doi: 10.1007/BF01870449. [DOI] [PubMed] [Google Scholar]
- Kukushkin N. I., Gainullin R. Z., Sosunov E. A. Transient outward current and rate dependence of action potential duration in rabbit cardiac ventricular muscle. Pflugers Arch. 1983 Oct;399(2):87–92. doi: 10.1007/BF00663902. [DOI] [PubMed] [Google Scholar]
- Mason J. W. Amiodarone. N Engl J Med. 1987 Feb 19;316(8):455–466. doi: 10.1056/NEJM198702193160807. [DOI] [PubMed] [Google Scholar]
- Mason J. W., Hondeghem L. M., Katzung B. G. Amiodarone blocks inactivated cardiac sodium channels. Pflugers Arch. 1983 Jan;396(1):79–81. doi: 10.1007/BF00584702. [DOI] [PubMed] [Google Scholar]
- Mason J. W., Hondeghem L. M., Katzung B. G. Block of inactivated sodium channels and of depolarization-induced automaticity in guinea pig papillary muscle by amiodarone. Circ Res. 1984 Sep;55(3):278–285. doi: 10.1161/01.res.55.3.278. [DOI] [PubMed] [Google Scholar]
- Nishimura M., Follmer C. H., Singer D. H. Amiodarone blocks calcium current in single guinea pig ventricular myocytes. J Pharmacol Exp Ther. 1989 Nov;251(2):650–659. [PubMed] [Google Scholar]
- Pallandi R. T., Campbell T. J. Resting, and rate-dependent depression of Vmax of guinea-pig ventricular action potentials by amiodarone and desethylamiodarone. Br J Pharmacol. 1987 Sep;92(1):97–103. doi: 10.1111/j.1476-5381.1987.tb11300.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Raeder E. A., Podrid P. J., Lown B. Side effects and complications of amiodarone therapy. Am Heart J. 1985 May;109(5 Pt 1):975–983. doi: 10.1016/0002-8703(85)90238-8. [DOI] [PubMed] [Google Scholar]
- Saikawa T., Carmeliet E. Slow recovery of the maximal rate of rise (Vmax) of the action potential in sheep cardiac Purkinje fibers. Pflugers Arch. 1982 Jul;394(1):90–93. doi: 10.1007/BF01108313. [DOI] [PubMed] [Google Scholar]
- Shenasa M., Denker S., Mahmud R., Lehmann M., Estrada A., Akhtar M. Effect of amiodarone on conduction and refractoriness of the His-Purkinje system in the human heart. J Am Coll Cardiol. 1984 Jul;4(1):105–110. doi: 10.1016/s0735-1097(84)80326-5. [DOI] [PubMed] [Google Scholar]
- Singh B. N., Vaughan Williams E. M. The effect of amiodarone, a new anti-anginal drug, on cardiac muscle. Br J Pharmacol. 1970 Aug;39(4):657–667. doi: 10.1111/j.1476-5381.1970.tb09891.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Singh B. N., Venkatesh N., Nademanee K., Josephson M. A., Kannan R. The historical development, cellular electrophysiology and pharmacology of amiodarone. Prog Cardiovasc Dis. 1989 Jan-Feb;31(4):249–280. doi: 10.1016/0033-0620(89)90033-9. [DOI] [PubMed] [Google Scholar]
- Varro A., Nakaya Y., Elharrar V., Surawicz B. Use-dependent effects of amiodarone on Vmax in cardiac Purkinje and ventricular muscle fibers. Eur J Pharmacol. 1985 Jun 19;112(3):419–422. doi: 10.1016/0014-2999(85)90791-5. [DOI] [PubMed] [Google Scholar]
- Vaughan Williams E. M. A classification of antiarrhythmic actions reassessed after a decade of new drugs. J Clin Pharmacol. 1984 Apr;24(4):129–147. doi: 10.1002/j.1552-4604.1984.tb01822.x. [DOI] [PubMed] [Google Scholar]
- Venkatesh N., Somani P., Bersohn M., Phair R., Kato R., Singh B. N. Electropharmacology of amiodarone: absence of relationship to serum, myocardial, and cardiac sarcolemmal membrane drug concentrations. Am Heart J. 1986 Nov;112(5):916–922. doi: 10.1016/0002-8703(86)90300-5. [DOI] [PubMed] [Google Scholar]
- Yabek S. M., Kato R., Singh B. N. Acute effects of amiodarone on the electrophysiologic properties of isolated neonatal and adult cardiac fibers. J Am Coll Cardiol. 1985 May;5(5):1109–1115. doi: 10.1016/s0735-1097(85)80012-7. [DOI] [PubMed] [Google Scholar]
- Yabek S. M., Kato R., Singh B. N. Effects of amiodarone and its metabolite, desethylamiodarone, on the electrophysiologic properties of isolated cardiac muscle. J Cardiovasc Pharmacol. 1986 Jan-Feb;8(1):197–207. doi: 10.1097/00005344-198601000-00029. [DOI] [PubMed] [Google Scholar]
- Zipes D. P., Prystowsky E. N., Heger J. J. Amiodarone: electrophysiologic actions, pharmacokinetics and clinical effects. J Am Coll Cardiol. 1984 Apr;3(4):1059–1071. doi: 10.1016/s0735-1097(84)80367-8. [DOI] [PubMed] [Google Scholar]