Regional and global myocardial function in the dog when nitrous oxide is added to halothane in the presence of critical coronary artery constriction

• Published in: Anesthesia and analgesia Vol. 65; no. 5; pp. 431 - 436
• Main Authors: RAMSAY, J. G, ARVIEUX, C. C, FOEX, P, PHILBIN, D. M, JEAVONS, P, RYDER, W. A, JONES, L. A
• Format: Journal Article
• Language: English
• Published: Hagerstown, MD Lippincott 01.05.1986
• Subjects: Anesthetics. Neuromuscular blocking agents; Animals; Biological and medical sciences; Constriction; Coronary Circulation - drug effects; Coronary Disease - physiopathology; Dogs; Drug Combinations; Halothane; Hemodynamics - drug effects; Medical sciences; Neuropharmacology; Nitrous Oxide - pharmacology; Pharmacology. Drug treatments; Fissipedia; Gases; Carnivora; Vertebrata; Cardiac performance; Mammalia; General anesthetic; Coronary artery; Drug interaction; Nitrogen protoxide; Dog
• ISSN: 0003-2999; 1526-7598
• DOI: 10.1213/00000539-198605000-00001

The effect of substituting 66% nitrous oxide for nitrogen on global and regional myocardial function before and after critical constriction of the left anterior descending coronary artery (LAD) was studied in six open-chested dogs anesthetized with 1% halothane (inspired). Regional myocardial function was measured in the region of the LAD and in the region of the left circumflex artery using sonomicrometry, and LAD blood flow was measured. Administration of nitrous oxide produced moderate depression of global performance. Regional shortening in both myocardial segments was reduced, and dysfunction also appeared in the LAD segment. This dysfunction was observed in the presence of both normal coronary blood flow, and after critical constriction. The appearance of dysfunction when coronary blood flow was unimpaired suggests that ischemia may not be the only cause of regional myocardial dysfunction.