Hemodynamic analysis and efficient control of ischemic heart in chronically instrumented dogs

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This study was carried out to establish the model of stunned myocardium with chronically instrumented dogs, and to analyze systemic and coronary hemodynamics under administration of several anesthetics and vasoactive drugs using the computer-based cardiovascular measurement system including the analysis of left ventricular pressure-volume relationship.The direct effects of several anesthetics on myocardial contractility were studied. The, direct myocardial depressant effect of etomidate, ketamine and propofol was dose dependent. Fentanyl had no negative inotropic effect. The hemodynamic actions of kromakalim were studied under the conscious state and during isoflurane anesthesia. The coronary vasodilating effects of isoflurane and cromakalim were basically additive until cromakalim exerted the maximal effects. The combined effects of dantrolen with propofol on the systemic and coronary hemodynamics were studied. A clinical dose of dantrolen reversed the decrease in heart rate, coronary … More blood flow and mean arterial pressure caused by propofol anesthesia.The hemodynamic and cardioprotective effects of sevoflurane in stunned myocardium were studied. Sevoflurane had a cardioprotective effect mediated through activation of mitochondria! K^ channels. The efficacy of MQ-154 after sevoflurane anesthesia for myocardial contractile function and oxygen consumption on stunned myocardium were studied. The combination of low-dose MCI-154 with sevoflurane could synergisucally act to produce full recovery of myocardial contraction without increase in myocardial oxygen consumption and heart rate after ischemia/reperfusion.The effects of sevoflurane on myocardial contractility and systemic and coronary hemodynamics, as compared with the effects of isoflurane under the same cardiac work condition, were studied. Myocardial depressant effects were comparable between sevoflurane and isoflurane, and both systemic and coronary vasodilatory effects of isoflurane were greater than those of sevoflurane. The cardiovascular effects of sevoflurane under acute normovolemic hemodilution were studied. Acute normovolemic hemodilution was beneficial during sevoflurane anesthesia with respect to the left ventricular-arterial coupling and mechanical efficiency. Less