Plasma concentrations and haemodynamic effects of d-sotalol after beta-blockade in dogs.
This study was designed to investigate the haemodynamic effects of d-sotalol at plasma concentrations producing class III antiarrhythmic effects. d-Sotalol 1, 4 and 10 mg/kg intravenously was given after beta-blockade (propranolol 0.25 mg/kg intravenously) to seven pentobarbital anaesthetized dogs. Left ventricular (LV) systolic and end-diastolic pressures, LV dP/dtmax, mean aortic pressure, stroke volume, cardiac output and total peripheral resistance were not significantly changed by d-sotalol. There was a linear correlation between the dose of d-sotalol infused and the plasma concentration of d-sotalol obtained. Heart rate decreased and QT-time increased with increasing plasma concentrations of d-sotalol, whereas the QRS-width did not change. There was a linear correlation between the decrease in heart rate and the increase in QT-time, and between the plasma concentration of d-sotalol and increase in QT-time. In conclusion, the study indicates that after beta-blockade, d-sotalol has no cardiodepressive effects at concentrations that prolong repolarization.
Mortensen
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Department of Medical Physiology, University of Tromsø, Norway.
Tande
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Kløw
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Refsum
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D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000097:blood / Q000494:pharmacology; D002316:Cardiotonic Agents / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D006321:Heart / Q000187:drug effects / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects*; D007275:Injections, Intravenous; D008297:Male; D013015:Sotalol / Q000008:administration & dosage / Q000097:blood* / Q000494:pharmacology; D013997:Time Factors
D000319:Adrenergic beta-Antagonists; D000889:Anti-Arrhythmia Agents; D002316:Cardiotonic Agents; D013015:Sotalol