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Effect of continuous blood flow on cerebrovascular perfusion and hemocoagulation in patients with implantable left ventricular assist device
Koňařík, Miroslav ; Szárszoi, Ondrej (advisor) ; Ošťádal, Petr (referee) ; Brát, Radim (referee)
Implantation of left ventricular assist devices (LVADs) is an integral treatment modality in patients with heart failure. In most cases, it refers to a machine which generates continuous blood flow with reduced pulse pressures. The effect of reduced pulsatility on organ function, such as homeostatic regulatory mechanisms is still unknown. The goal of our study was to understand whether continuous blood flow generated by mechanical support devices affects cerebrovascular regulatory mechanisms (study A), and whether or not hemocoagulation is affected in regard to complications relating to hemocompatibility (study B). Study A utilized finger plethysmography and TCD ultrasonography to detect possible changes in static cerebral auto-regulation when compared to a range of rotations per minute (rpm) of the LVAD, which served as a model for either accentuation or reduction in residual arterial pulsatility. Study B divided patients with implanted LVADs based on the incidence of selected thrombophilic mutations. Both groups of patients were placed on individualized anticoagulation protocols. The results were focused on the incidence of thromboembolic and hemorrhagic complications, and eventual morbidity/mortality of the patient. Our findings did not confirm disruption to static cerebral auto-regulation,...
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Protection of the ischemic myocardium during early stages of the ontogenetic development
Doul, Jan ; Charvátová, Zuzana (advisor) ; Adamcová, Michaela (referee) ; Szárszoi, Ondrej (referee)
Neonatal hearts exhibit higher resistance to ischemia-reperfusion (I/R) injury and cannot be further protected by ischemic preconditioning (IPC). Nothing is known about ischemic postconditioning (IPoC) in neonatal hearts yet. Rat hearts isolated on postnatal days 1, 4, 7 and 10 were perfused according to Langendorff. Hearts were exposed to 40 or 60 min of ischemia and reperfusion up to the maximum recovery of developed force. IPoC was induced by protocols 3x10s, 3x30s, 3x60s and 5x10s. Tolerance to ischemia did not change from day 1 to day 4 but decreased to days 7 and 10. On day 10, none of the IPoC protocols 3x10s, 3x30s and 3x60s led to significant protection, not even when the ischemia was prolonged to 60 min. The 3x30s protocol (the most effective from the previous) was also applied on days 1, 4 and 7 without any significant effect. However, in the next series of experiments, protocol 5x10s had significant protective effect on day 10. IPC and IPoC in adult hearts act through mitochondrial- K-ATP channels and nitric oxide (NO). Surprisingly mito-K-ATP blocker (5-HD) administered 5 min before ischemia and during first 20 min of reperfusion had no effect on neonatal resistance or on IPoC on day 10. Another group of hearts was used for analysis of 3- nitrotyrosine (3-NT) and serum samples were...
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The role of nitric oxide in cardioprotection induced by chronic hypoxia
Mandíková, Petra ; Neckář, Jan (advisor) ; Szárszoi, Ondrej (referee)
The aim of present project was to uncover the effect of pharmacological increase in acute and chronic nitric oxide (NO) production on cardioprotective effect of chronic hypoxia. We studied the effect of NO donor molsidomine on hemodynamic conditions and ischemia - induced myocardium injury. Male Wistar rats were exposed to continual hypoxia in a normobaric chamber (10 % O2, 4 weeks). Rats received molsidomine either chronically (15 mg/kg/day) in drinking water or acutely (10 mg/kg) in saline infused 30 min before ischemia. Control rats were kept under normoxia and treated in a corresponding manner. Adaptation to chronic hypoxia resulted in development of pulmonary hypertension. Chronic treatment with molsidomine slightly reduced these consequences of chronic hypoxia but it had no effect on increased cardiac ischemic tolerance in chronically hypoxic rats. On the other hand acute treatment with molsidomine significantly reduced infarct size and increased the number of arrhythmias in both normoxic and chronically hypoxic animals. In conclusion, our data suggests that acute increase in availability of NO is cardioprotective in both normoxic and chronically hypoxic rats contrary to its chronic increase which seems to have no protective contribution.
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Methods and consequences of some neurosurgical interventions in animal model and in human clinic. Pinealectomy and intracerebroventricular application.
Řezáčová, Lenka ; Tichý, Michal (advisor) ; Szárszoi, Ondrej (referee) ; Přibáň, Vladimír (referee)
Clinical surgical techniques of pinealectomy and intracerebroventricular (i.c.v) cannulation are still used in the clinic in indicated cases. In research, there is an effort to replace these classical surgical techniques by other means. However, these various new models often do not reflect the complexity of the functions taking place in the living organism as a whole. The thesis shows that these surgical techniques should be also a part of biomedical research in the future, as they still bring new important information. In the experiment, the pinealectomy can serve as a model of resection or depletion (removal of natural hormone secretion), while i.c.v. application of the active substance to the ventricles on the contrary as a model of addition or substitution. The practical part of the thesis is divided into 4 areas: A) pinealectomy - an animal models, B) pinealectomy - in the experiment, C) pinealectomy - in the clinical practice and D) intracerebroventricular application - in the experiment. The work describes in detail the surgical techniques and discuss possible consequences of pinealectomy in 6 animal species (and their comparison) and in humans. It also includes an experiment with pinealectomy in a rat and a clinical study in patients with pineal cyst and subsequent pinealectomy. The work...
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Oxygen consumption in awake cardiac surgical patients
Pořízka, Michal ; Stříteský, Martin (advisor) ; Szárszoi, Ondrej (referee) ; Šetina, Marek (referee)
OBJECTIVES: Standard blood flow rates for cardiopulmonary bypass have been assumed to be the same for awake cardiac surgery with thoracic epidural anesthesia as for general anesthesia. However, compared to general anesthesia, awake cardiac surgery with epidural anesthesia may be associated with higher oxygen consumption due to missing effect of general anesthetics. This may result in insufficient oxygen delivery and lactic acidosis when standard blood flow rates were used. The primary aim of our study was to investigate if standard blood flow rates are adequate in awake cardiac surgery. The secondary aim was to evaluate postoperative clinical outcomes of patients undergoing awake cardiac surgery. METHODS: Forty-seven patients undergoing elective on-pump cardiac surgery were assigned to receive either epidural (Group TEA, n=17), combined (Group TEA-GA, n=15) or general (Group GA, n=15) anesthesia. To monitor adequacy of standard blood flow rates, arterial lactate, acid base parameters, central venous and jugular bulb saturation were measured at six time points during in all groups. Blood flow rates were adjusted when needed. Subsequently, early and late postoperative outcome data including hospital and 3-year mortality was recorded and compared among the study groups RESULTS: No lactic acidosis has...
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Percutanous electrogastrography, principle and posibilities of clinical application in abdominal surgery
Fraško, Roman ; Krška, Zdeněk (advisor) ; Maršálek, Petr (referee) ; Szárszoi, Ondrej (referee)
Author of this dissertation presentation discuss in the begining definition and historical consequences of origin and consecutive evolution of the method of percutaneous electrogastrography. Intimately is described physiology, anatomy, embryology and function of gastrointestinal tract with special interest on construction and function of the stomach. Next to this author analyses current knowledge about location and function of the gastric pace setter. The technique of used perctutaneous electrogastrography equipmentt is described. In the second part results of original studies monitoring restoration of peristalsis in perioperative period at patients after open and laparoscopic cholecystectomy and laparoscopic non-adjustable gastric banding are discussed. Furthermore results of EGG measurement of patients with mechanic, vascular and paralytic intestinal obstruction are presented in correlation with plasma levels of interleukin 1β, interleukin-6, procalcitonin and C-reactive protein. Key words: Percutanous electrogastrography, laparoscopic cholecystectomy, laparoscopic gastric bandage, inflammatory mediators, intestinal obstruction.
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Hemodynamic adaptation mechanisms of heart failure to percutaneous venoarterial extracorporeal circulatory support
Hála, Pavel ; Kittnar, Otomar (advisor) ; Szárszoi, Ondrej (referee) ; Havránek, Štěpán (referee)
Introduction: Venoarterial extracorporeal membrane oxygenation (VA ECMO) is widely used in the treatment of circulatory failure, but repeatedly, its negative effects on the left ventricle (LV) have been observed. The purpose of this study is to assess the influence of ex- tracorporeal blood flow (EBF) on systemic hemodynamic changes and LV performance parameters during VA ECMO therapy of decompensated heart failure. Methods: Porcine models of low-output chronic and acute heart failure were developed by long-term fast cardiac pacing and coronary hypoxemia, respectively. Profound signs of circulatory decompensation were defined by reduced cardiac output and tissue hypoperfusion. Sub- sequently, under total anesthesia and artificial ventilation, VA ECMO was introduced. LV performance and organ specific parameters were recorded at different levels of EBF using an LV pressure-volume loop analysis, arterial flow probes on carotid and subclavian arteries, and transcutaneous probes positioned to measure cerebral and forelimb regional tissue oxygen saturations. Results: Conditions of severely decompensated heart failure led to systemic hypotension, low tissue and mixed venous oxygen saturations, and increase in LV end-diastolic pressure. By increasing the EBF from minimal flow to 5 L/min, we observed a...
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Protection of the ischemic myocardium during early stages of the ontogenetic development
Doul, Jan ; Charvátová, Zuzana (advisor) ; Adamcová, Michaela (referee) ; Szárszoi, Ondrej (referee)
Neonatal hearts exhibit higher resistance to ischemia-reperfusion (I/R) injury and cannot be further protected by ischemic preconditioning (IPC). Nothing is known about ischemic postconditioning (IPoC) in neonatal hearts yet. Rat hearts isolated on postnatal days 1, 4, 7 and 10 were perfused according to Langendorff. Hearts were exposed to 40 or 60 min of ischemia and reperfusion up to the maximum recovery of developed force. IPoC was induced by protocols 3x10s, 3x30s, 3x60s and 5x10s. Tolerance to ischemia did not change from day 1 to day 4 but decreased to days 7 and 10. On day 10, none of the IPoC protocols 3x10s, 3x30s and 3x60s led to significant protection, not even when the ischemia was prolonged to 60 min. The 3x30s protocol (the most effective from the previous) was also applied on days 1, 4 and 7 without any significant effect. However, in the next series of experiments, protocol 5x10s had significant protective effect on day 10. IPC and IPoC in adult hearts act through mitochondrial- K-ATP channels and nitric oxide (NO). Surprisingly mito-K-ATP blocker (5-HD) administered 5 min before ischemia and during first 20 min of reperfusion had no effect on neonatal resistance or on IPoC on day 10. Another group of hearts was used for analysis of 3- nitrotyrosine (3-NT) and serum samples were...
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Gender differences in myocardial apoptosis of the patients after heart tranplantation.
Smetana, Michal ; Szárszoi, Ondrej (advisor) ; Brát, Radim (referee) ; Neckář, Jan (referee)
Gender differences in myocardial apoptosis of the patients after heart transplantation Background: Many functions of the cardiovascular apparatus are influenced by gender. The aim of our study was to find out the sensitivity to perioperative ischemia of the donor female and male myocardium; and determine how the organism affects the donor myocardium of the other sex after heart transplantation (detection of apoptosis), and whether the investigated biomarkers can predict primary graft dysfunction (PGD). Methods: The research was divided into three prospective studies. The Study 1 included 81 patients undergoing heart transplantation from September 2010 to January 2013. Patients were divided into two groups according to male allograft and female allograft. In order to prove myocardial necrosis the high-sensitive cardiac troponin T (hs-cTnT) method was used. Apoptosis was determined by immunohistochemical detection of caspase-3, Bcl-2, and by the TUNEL method. The Study 2 includeded 58 patients divided into four groups according to gender; both of the recipient and the donor. Apoptosis (caspase-3, Bcl-2, TUNEL) was analysed in these groups during the two-year follow-up. Into Study 3 64 patients were involved. We investigated the relationship in between these biomarkers and the development of PGD after...
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