Interactions of adrenaline and magnesium on the cardiovascular system of the baboon.
Cardiovascular variables were measured in baboons before and during an adrenaline infusion at 1 microgram/kg/min, and following two bolus injections of either MgSO4 60 mg/kg or saline. Arterial blood pressure (ABP), systemic vascular resistance (SVR), central venous pressure (CVP), pulmonary arterial pressure and pulmonary capillary wedge pressure were all elevated by the adrenaline infusion. Cardiac output (CO), stroke volume (SV) and heart rate were unchanged but multifocal arrhythmias occurred. Mg infusion abolished arrhythmias and markedly increased CO and SV. SVR was reduced below baseline values by Mg, and ABP and CVP returned toward baseline. Saline did not alter adrenaline-induced changes in any way. It is concluded that Mg has powerful antiarrhythmic effects in the presence of catecholamines and, in addition, may have useful alpha-adrenergic antagonist effects.
James
M F
MF
Department of Anaesthesia, University of the Witwatersrand, Johannesburg, South Africa.
Cork
R C
RC
Harlen
G M
GM
White
J F
JF
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000517:prevention & control; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D002319:Cardiovascular System / Q000187:drug effects*; D004347:Drug Interactions; D004837:Epinephrine / Q000494:pharmacology*; D006339:Heart Rate / Q000187:drug effects; D008274:Magnesium / Q000494:pharmacology*; D010215:Papio; D014655:Vascular Resistance / Q000187:drug effects
D008274:Magnesium; D004837:Epinephrine