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Acute cardiodepressant effects induced by bolus intravenous administration of amiodarone in rabbits
Author(s) -
Lessa Marcos Adriano,
Tibiriçá Eduardo
Publication year - 2005
Publication title -
fundamental and clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 73
eISSN - 1472-8206
pISSN - 0767-3981
DOI - 10.1111/j.1472-8206.2004.00308.x
Subject(s) - amiodarone , medicine , hemodynamics , lidocaine , anesthesia , bolus (digestion) , vascular resistance , contractility , cardiac output , heart rate , mean arterial pressure , cardiology , blood pressure , atrial fibrillation
Amiodarone is a potent anti‐arrhythmic with a large pharmacological spectrum that shares the mechanisms of action of all classes of anti‐arrhythmic drugs. Originally used in the treatment of supraventricular arrhythmias, it has also been used to treat ventricular tachyarrhythmias. The recent inclusion of amiodarone in the Advanced Cardiac Life Support protocols warrants the characterization of the hemodynamic profile resulting from the rapid venous administration of the drug. Thus, the main purpose of the present study was to investigate the acute hemodynamic profile resulting from the bolus i.v. injection of amiodarone, compared with bolus i.v. administration of lidocaine. We investigated the acute hemodynamic effects of amiodarone and lidocaine, in an experimental model of open‐chest pentobarbital‐anesthetized rabbits ( n = 24). Amiodarone (5 mg/kg) induced immediate reductions in mean arterial pressure (MAP) of 32 ± 5% ( P < 0.001), accompanied by reductions in cardiac contractility and relaxation, as assessed by left ventricular (LV) +d P /d t max and −d P /d t max (40 ± 4 and 36 ± 4% respectively) ( P < 0.001), heart rate (HR) 10 ± 1% ( P < 0.05), cardiac output (CO) 24 ± 5% ( P < 0.001) and systemic vascular resistance (SVR) 19 ± 3.5% ( P < 0.05). Lidocaine (3 mg/kg) induced reductions in: MAP of 18 ± 7% ( P < 0.001), LV +d P /d t max and −d P /d t max (40 ± 5 and 22 ± 7% respectively) ( P < 0.001), HR 7 ± 1% ( P < 0.01) and CO of 23 ± 6% ( P < 0.001). SVR increased by 9 ± 1.5% ( P > 0.05). It is concluded that rapid i.v. administration of both amiodarone and lidocaine induces significant cardiovascular depression mainly characterized by immediate reductions in cardiac contractility.