THE EFFECTS OF DIAZEPAM (VALIUM) ON LEFT VENTRICULAR FUNCTION AND SYSTEMIC VASCULAR RESISTANCE

• Published in: The Journal of pharmacology and experimental therapeutics Vol. 173; no. 2; pp. 364 - 370
• Main Authors: Abel, R M, Staroscik, R N, Reis, R L
• Format: Journal Article
• Language: English
• Published: United States American Society for Pharmacology and Experimental Therapeutics 01.06.1970
• Subjects: Animals; Aorta; Blood Pressure - drug effects; Diazepam - administration & dosage; Diazepam - pharmacology; Dogs; Extracorporeal Circulation; Heart Rate - drug effects; Heart Ventricles - drug effects; Injections, Intravenous; Muscle Contraction - drug effects; Vascular Resistance - drug effects; Ventricular Function
• ISSN: 0022-3565; 1521-0103

The effects of intravenous diazepam on left ventricular function and systemic vascular resistance were determined in anesthetized dogs on cardiopulmonary bypass with heart rate and aortic pressure maintained constant. Immediately after diazepam was given an increase in peak isovolumetric left ventricular pressure and dp/dt max occurred in every animal, and these effects persisted for 30 minutes in 9 of 10 dogs. Forcevelocity and length-tension relations also demonstrated improved cardiac performance after diazepam. Within 45 seconds after the administration of diazepam, a significant decrease in systemic vascular resistance occurred in all animals. A transient rise in resistance toward control levels occurred during the following 3 to 7 minutes, but within 10 minutes after injection, decreases recurred. Since diazepam augments myocardial contractility and produces systemic vasodilatation, it may have a salutary effect when employed as a sedative or tranquilizer drug in patients with impaired cardiac function.