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Cardiac tolerance to oxygen deprivation: the effects of inhalational and intravenous anesthetics
Říha, Hynek ; Pirk, Jan (advisor) ; Bultas, Jan (referee) ; Geršl, Vladimír (referee)
Background: Surgical procedures are invariably accompanied by the use of inhalational and intravenous anesthetics. Both groups have strong influence on cardiovascular system by the interaction with myocardial oxygen supply/demand ratio and cardiomyocyte functions at the level of cell membranes, ion channels and regulatory enzymes. Aims: 1. To examine the effects of different isoflurane concentrations on the left ventricular (LV) dimensions and systolic function in the rat. 2. To examine the effects of isoflurane-induced myocardial preconditioning (APC) on the cardiac tolerance to ischemia- reperfusion (I-R) injury. 3. To compare the influence of anesthesia, based on ketamine- dexmedetomidine (KET-DEX), on the release of biochemical markers of myocardial injury and the early postoperative course with the anesthesia, based on sevoflurane-sufentanil (SEVO), in the patients undergoing coronary artery bypass grafting (CABG). Methods: 1. We carried out transthoracic echocardiographic examination in the rats immobilized by 1.5-3% concentration of isoflurane. 2. After inducing APC by isoflurane (0.5 and 1 MAC), we evaluated ventricular arrhythmias during regional ischemia (45 min), induced by the occlusion of the left anterior descending artery, and subsequent reperfusion (60 min), using the model of...
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The effect of methadone on cardiac ischemic tolerance in rats
Mošovská, Linda ; Neckář, Jan (advisor) ; Říha, Hynek (referee)
Opioids are considered as a dangerous addictive substances which are widely used in medicine for their strong analgetic effects. Opioids (such as morphine and methadon) may nevertheless play an important role in the resistance of the heart to ischemia by reducing the rate of cell damage. This protective effect is well understood about morphine but we don't know almost nothing about effects of methadone on the myocardium. The main aim of this thesis was to find out how chronic methadone treatment affects ischemic tolerance of rat hearts. For our experiments we used Wistar rats in two series. In the first series we administered morphine (10 mg/kg/day, i.m.) or methadone (2 mg/kg/day, i.m.) for 10 days. In the second experiment series we administered methadon for 28 days (2 mg/kg/day, i.m.). For analysis of the ischemic heart tolerance we used the isolated perfused heart method. Incidence and severity of ischemia and reperfusion arrhythmias were analyzed during the 50 min of ischemia and early reperfusion. Infarct size was analyzed histochemically, using tetrazolium salts and KMnO4 1 h after reperfusion and was determined by planimetric method. In the first series of experiments analyzing the effect of 10-day administration of both opioids on the resistance of the heart to ischemia we did not find a...
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Cardiac tolerance to oxygen deprivation: the effects of inhalational and intravenous anesthetics
Říha, Hynek ; Pirk, Jan (advisor) ; Bultas, Jan (referee) ; Geršl, Vladimír (referee)
Background: Surgical procedures are invariably accompanied by the use of inhalational and intravenous anesthetics. Both groups have strong influence on cardiovascular system by the interaction with myocardial oxygen supply/demand ratio and cardiomyocyte functions at the level of cell membranes, ion channels and regulatory enzymes. Aims: 1. To examine the effects of different isoflurane concentrations on the left ventricular (LV) dimensions and systolic function in the rat. 2. To examine the effects of isoflurane-induced myocardial preconditioning (APC) on the cardiac tolerance to ischemia- reperfusion (I-R) injury. 3. To compare the influence of anesthesia, based on ketamine- dexmedetomidine (KET-DEX), on the release of biochemical markers of myocardial injury and the early postoperative course with the anesthesia, based on sevoflurane-sufentanil (SEVO), in the patients undergoing coronary artery bypass grafting (CABG). Methods: 1. We carried out transthoracic echocardiographic examination in the rats immobilized by 1.5-3% concentration of isoflurane. 2. After inducing APC by isoflurane (0.5 and 1 MAC), we evaluated ventricular arrhythmias during regional ischemia (45 min), induced by the occlusion of the left anterior descending artery, and subsequent reperfusion (60 min), using the model of...
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