Effects of exogenous isoflourane on postischemic dysfunction (Stunned myocardium) in the isolated rabbit heart

DONATO M; MARINI J; D ANNUNZIO V; GELPI RJ

L A Archives of Cardiovascular Sciences

SERVCOR

Lugar: Belho Horizonte; Año: 2000 vol. 1 p. 31 - 47

1677-6542

There is experimental evidence, though it is controversial, that volatil anesthesics protect heart from postischemic ventricular dysfunction (?stunned myocardial?). However, the drug?s effects on the diastolic phase of the cardiac cycle are less known. The aim of this work was to determine the effect of Isofluorane when it was administered 10 minutes before ischemia on the systolic and diastolic function of the ?stunned myocardium?. Rabbit isolated isovolumic hearts were perfused according to Langendorff?s technique, and subjected to 15 minutes global ischemia and 30 minutes reperfusion. A small latex ballon was inserted into the left ventricle via the left atrium which allowed to measure the ventricular end-diastolic pressure (diastolic stiffness) and calculate the developed pressure, the maximal rate of pressure generation and maximal rate of pressure decay (+ dP/dtmax and -dP/dtmax), the ratio between these two variables (+P/-P), and the time constant of isovolumic relaxation (t, Tau). The administration of Isofluorane before ischemia did not atenuated the sistolyc alterations without modifies the isovolumic relaxation, but the diastolic stiffness increased significantly