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Effects of amiodarone on cardiac electrophysiology and inducibility of arrhythmias in chronically infarcted dogs late arrhythmias hemodynamics and sympatholytic actions


, : Effects of amiodarone on cardiac electrophysiology and inducibility of arrhythmias in chronically infarcted dogs late arrhythmias hemodynamics and sympatholytic actions. Journal of Cardiovascular Pharmacology 16(6): 896-904

The electrophysiological and antiarrhythmic effects of acute (2 and 10 mg/kg i.v.) and chronic (400 mg/day p.o. for 28 days) amiodarone (AM) treatment were compared in anaesthetised dogs with 5-6-day-old myocardial infarcts. Intravenous AM prolonged the RR interval, sinus node recovery trime, the PR interval, and atrial to His conduction time by 36, 33, 25, and 36%, respectively. Corresponding increases after oral aminodarone were 50, 57, 12, and 26%. Atrial and His-Purkinje conduction times were unchanged. Atrial and ventricular refractory periods were increased especially after oral treatment. Oral AM additionally prolonged QRS, QT, and paced QT (by 4, 34, and 19%, respectively). Effects of oral AM on ventricular repolarisation and on the fast inward sodium current were confirmed in vitro. Both modes of AM administration protected against inducible arrhythmias, an effect that was more marked during normal sinus rhythm than during pacing in orally treated dogs. Oral amiodarone failed to protect against spontaneous late arrhythmias 24 h after infarction whilst both modes of administration noncompetitively inhibited isoprenaline-induced tachycardia. Oral AM reduced blood pressure (13%) and LV dP/dt/P (24%) whereas cardiac output was maintained by an increase in stroke volume. It was concluded that oral AM is haemodynamically well tolerated and that prolonged ventricular repolarisation enhanced by bradycardia together with sympatholytic actions may be important mechanisms for antiarrhythmic efficacy, whereas the mechanisms involved in i.v. efficacy are less clear but may depend, at least partly, on sympatholytic actions and perhaps (tentatively) on sodium channel block in Purkinje tissue.

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PMID: 1704981


Other references

Wiles, I.A., 1958: Volunteer workers in medical installations. Medical Bulletin of the U. S. Army, Europe. United States. Army, Europe. Medical Division 15(10): 215-218

Speller, D.C., 1988: The clinical impact of antibiotic resistance. Journal of Antimicrobial ChemoTherapy 22(5): 583-586

Calleja, G.B., 1970: Flocculation in Schizosaccharomyces pombe. Journal of General Microbiology 64(2): 247-250

Petter, O.; Kipping, D., 1972: Immunoelectrophoretic studies in various collagen diseases in dermatology. Zeitschrift für Haut- und Geschlechtskrankheiten 47(2): 53-62

Trost, H.A.; Heissler, H.E.; Claussen, G.; Gaab, M.R., 1991: Testing the hydrocephalus shunt valve: long-term bench test results of various new and explanted valves. The need for model for testing valves under physiological conditions. 13 new and 19 explanted hydrocephalus shunt valves were tested under perfusion for two weeks, using a modified ASTM test. Some manufacturers seem to have problems with quality control. Our results show large deviations in pressure-flow-characteris...

Sohal K.S.; Saini A.K., 1992: Sem & thur soils in Punjab; 1968-69 to 1984-85. Geographical Review of India: , Pages 10-20. 1992.

Panin L.E.; Kuz'menko D.I.; Kolpakov A.R., 1982: Role of blood lipo proteins in adaptive changes in rat liver mitochondria. Bulletin of Experimental Biology & Medicine 94(9): 1220-1222

Sato, Y.; Naito, H.; Takase, A.; Yoshiki, T., 1986: A case of T cell lymphoma with marked proliferation of histiocytes. Japanese Journal of Clinical Hematology 27(2): 225-230

Murata, K.J.; Friedman, I.I.; Madsen, B.M., 1967: Carbon-13--rich diagenetic carbonates in miocene formations of california and Oregon. Carbon unusually rich in C(13)(deltaC(13) = +5.4 to +19.0 per mil relative to the Peedee belemnite carbonate standard of the University of Chicago) is characteristic of certain diagenetic limestones and dolomites in the Miocene Monterey Shale of C...

Donaldson, R.C.; Paletta, F.X., 1963: An Improved Method Of Direct Cannulation Of The Carotid Artery For Infusion. American Journal of Surgery 106: 712-715