Faculty Collaboration Database

Evaluation of myocardial contractility in the chronically instrumented dog with intact autonomic nervous system function: effects of desflurane and isoflurane. Acta Anaesthesiol Scand 1993 Feb;37(2):203-10

Date

02/01/1993

Pubmed ID

8447212

DOI

10.1111/j.1399-6576.1993.tb03702.x

Scopus ID

2-s2.0-0027471990 (requires institutional sign-in at Scopus site)   28 Citations

Abstract

Characterization of changes in myocardial contractility using indices derived from ventricular pressure-segment length loops in animals with intact autonomic nervous system (ANS) function is complicated by alterations in systemic hemodynamics mediated by baroreceptor reflexes and by spontaneous respiration and its effects on ventricular pressure and filling. This investigation examined and compared the effects of desflurane and isoflurane on myocardial contractility in dogs with intact ANS reflexes using techniques designed to overcome these potential difficulties. Two groups comprising 18 experiments were performed using nine dogs chronically instrumented for measurement of aortic and left ventricular pressure, the maximum rate of increase of left ventricular pressure (dP/dt), subendocardial segment length, cardiac output and intrathoracic pressure. A brief occlusion of the inferior vena cava was used to alter preload to generate pressure-length loops prior to onset of baroreceptor reflex-mediated increases in heart rate. Respiratory variation in ventricular pressure was negated by calculation of "transmural pressure" via instantaneous subtraction of intrathoracic pressure from corresponding left ventricular pressure. Contractility was then evaluated in the conscious and anesthetized states using transmural pressure-length loops and calculation of the preload recruitable stroke work (PRSW) relationship. Dogs were anesthetized with 1.25, 1.5, or 1.75 MAC desflurane or isoflurane and measurements were repeated after 30 min of equilibration at each anesthetic concentration. Desflurane and isoflurane produced similar declines in PRSW slope [Mw; 41 +/- 6 (5.5 +/- 0.8) during 1.75 MAC desflurane compared to 43 +/- 5 mmHg (5.7 +/- 0.7 kPa) during 1.75 MAC isoflurane], indicating that these agents cause similar depression of contractile state at equivalent MAC.(ABSTRACT TRUNCATED AT 250 WORDS)

Author List

Pagel PS, Kampine JP, Schmeling WT, Warltier DC

MESH terms used to index this publication - Major topics in bold

Anesthetics
Animals
Autonomic Nervous System
Blood Pressure
Cardiac Output
Dogs
Dose-Response Relationship, Drug
Evaluation Studies as Topic
Heart
Heart Rate
Isoflurane
Myocardial Contraction
Oxygen
Stroke Volume
Ventricular Function, Left