Administration of sevoflurane and isoflurane prior to prolonged global ischemia improves heart function in isolated rat heart.

Abstract

The Langendorff model was used to determine whether pretreatment with sevoflurane, isoflurane, or ischemic preconditioning (IP) could protect the myocardium of rats against global ischemia. After 15-min perfusion, each isolated heart was assigned to (1) CONTROL GROUP: no pretreatment, (2) Sevoflurane group: 20-min exposure of 1.7% sevoflurane prior to ischemia, (3) Isoflurane group: exposure of 1.4% isoflurane prior to ischemia, or (4) IP group: two 5-min ischemic periods separated by 5-min perfusion. Following pretreatment, each heart was exposed to 20-min global normothermic ischemia followed by 60-min reperfusion. Heart rate (HR), left ventricular end-diastolic pressure (LVEDP), left ventricular developed pressure (LVDP), HR x LVDP, left ventricular contractility (+dLVP/dt), and coronary flow were recorded continuously. Myocardial damage was assessed by hematoxylin and eosin (H&E) staining. No significant differences (P > 0.05) in hemodynamic variables were recorded among the four groups before the experiment. After ischemia during reperfusion, sevoflurane, isoflurane and IP pretreated hearts recovered left ventricular function significantly better than control hearts. After 60-min reperfusion, +dLVP/dt recovered to 6.84 +/- 1.06%, 23.3 +/- 4.80%, 42.3 +/- 3.16%, and 59.6 +/- 5.75% of baseline values respectively for control, sevoflurane, isoflurane and IP groups. HR x LVDP recovered to 8.9 +/- 1.7%, 27.9 +/- 6.42%, 38.7 +/- 2.78%, and 59.6 +/- 3.98% respectively. H&E staining supported the hemodynamic data in that hearts pretreated with sevoflurane, isoflurane and IP showed significantly less ischemic damage when compared to control hearts. Our study shows pretreatment with sevoflurane or isoflurane provided moderate protection to the isolated heart against prolonged periods of global ischemia.