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Calcium reverses global and regional myocardial dysfunction caused by the combination of verapamil and halothane
Author(s) -
Lehot J. J.,
Leone B. J.,
Foëx P.
Publication year - 1987
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1987.tb02599.x
Subject(s) - medicine , verapamil , halothane , calcium , anesthesia , pharmacology , cardiology
In order to evaluate the effects of the combination of halothane and verapamil on left ventricular function and coronary blood flow (CBF), six sheep were anaesthetized with halothane (1.2% inspired) and given increasing cumulative doses of intravenous verapamil. Regional myocardial function was assessed by sonomicrometry in the areas supplied by the left anterior descending coronary artery (LAD) and the left circumflex coronary artery (LC). Changes in global haemodynamics, atrioventricular conduction, LV relaxation and systolic shortening alter 0.32 mg·kg ‐1 intravenous verapamil indicated impaired left ventricular function. Significant myocardial dysfunction (post‐systolic shortening) occurred in the LAD territory, accompanied by a 64% decrease (42 ± 6 to 15 ± 3, p < 0.01) in coronary perfusion pressure (CPP). Coronary blood flow in the LC segment decreased 83% (102 ± 15 to 17 ± 13, P < 0.01) as coronary reserve was exhausted with the decrease in CPP. Calcium chloride reversed the impairment of global and regional myocardial function observed with verapamil, improved the impaired left ventricular relaxation, but did not significantly alter atrioventricular conduction. Thus the combination halothane‐verapamil can cause significant left ventricular depression and myocardial dysfunction, possibly by inducing suhendocardial ischaemia or by direct pharmacologic effect. calcium chloride reverses this regional myocardial dysfunction as well as the deleterious global haemodynamic changes caused by halothane‐verapamil; however, the changes in atrioventricular conduction are not corrected by calcium.