DOSE-RELATED EFFECTS OF ISOFLURANE ASSOCIATED WITH LOW PLASMA CONCENTRATIONS OF VERAPAMIL ON GLOBAL AND REGIONAL FUNCTION IN NORMAL AND COMPROMISED CANINE MYOCARDIUM

• Published in: British journal of anaesthesia : BJA Vol. 66; no. 6; pp. 673 - 682
• Main Authors: ARVIEUX, C.C., VIDECOQ, M., RAMSAY, J.G., STONE, J.G., FOËX, P., RYDER, W.A.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.1991; Oxford University Press
• Subjects: Anaesthetics; Anesthetics. Neuromuscular blocking agents; Animals; Biological and medical sciences; Blood Pressure - drug effects; Coronary Circulation - drug effects; Coronary Disease - blood; Coronary Disease - physiopathology; Disease Models, Animal; Dogs; Dose-Response Relationship, Drug; Drug Interactions; Heart - drug effects; Heart - physiopathology; Heart: myocardial function; ischaemia; Isoflurane - pharmacology; Medical sciences; Neuropharmacology; Pharmacology. Drug treatments; Vasodilation - drug effects; verapamil; Verapamil - blood; volatile: isoflurane; ischaemia; Heart: myocardial function; volatile: isoflurane; verapamil; Anaesthetics; Volatile compound; Fissipedia; Carnivora; Vertebrata; Drug combination; Cardiac performance; Mammalia; General anesthetic; Animal; Calcium antagonist; Drug interaction; Dog
• ISSN: 0007-0912; 1471-6771
• DOI: 10.1093/bja/66.6.673

Global and regional myocardial functions were studied in seven open-chest dogs with constant low plasma concentrations of verapamil as increasing concentrations of isoflurane (0.75, 1, 1.5 MAC) were administered in the presence of normal myocardial perfusion and after application of critical constriction of the left anterior descending coronary artery. In the presence of verapamil, increases in isoflurane concentrations caused dose-dependent myocardial depression both before and after critical coronary constriction. The systemic and coronary vasodilatation associated with high concentrations of isoflurane did not occur in the presence of verapamil. The association of verapamil with isoflurane caused regional myocardial dysfunction that worsened at high isoflurane concentrations. This regional dysfunction could not be antagonized in two dogs. The effects of isoflurane on regional function were not modified by application of a critical coronary constriction.