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The stress response to cardiac catheterisation. The concentration of stress markers of the hypothalamic-pituitary-adrenal axis
Skarlandtová, Hana ; Kittnar, Otomar (advisor) ; Gregor, Pavel (referee) ; Svoboda, Miroslav (referee)
In our study, we analyzed four stress markers (cortisol, cortisone, DHEA and DHEAS) in blood serum in young sows using minimally invasive heart catheterisation as the stress factor. The marker levels were assessed in four defined periods of the experiment, beginning with the baseline level on the day before intervention (1), the second period was after the introduction of anaesthesia (2), the third was after conducting tissue stimulation or ablation (3), and the final period was after the end of the catheterisation (4). Cortisol and cortisone were detected using HPLC method, DHEA(S) by commercial kits. For statistical analyses non-parametric tests were used (due to non standard Gaussian data distribution). In our study we arranged these experiments: 1. Diurnal variability in these markers concentration during heart catheterisation was tested. 2. Are there differences between stress markers concentration the day before experiment (sampling 1) and in the day of the catheterisation (samplings 2, 3, 4)? 3. Are there differences between these markers concentration during operation (the first sampling was excluded)? 4. The cortisol/cortisone ratio was calculated. We found only minimal statistical differences in studied markers between the morning and afternoon group (p > 0.05) in experiment 1. For tested...
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Utilization of GRID technology in processing of medical information
Kulhánek, Tomáš ; Šárek, Milan (advisor) ; Kittnar, Otomar (referee) ; Anjum, Ashiq (referee)
This thesis focuses on selected areas of biomedical research in order to benefit from current computational infrastructures established in scientific community in european and global area. The theory of computation, parallelism and distributed computing, with focus on grid computing and cloud computing, is briefly introduced. Exchange of medical images was studied and a seamless integration of grid-based PACS system was established with the current distributed system in order to share DICOM medical images. Voice science was studied and access to real-time voice analysis application via remote desktop technology was introduced using customized protocol to transfer sound recording. This brings a possibility to access current legacy application remotely by voice specialists. The systems biology approach within domain of human physiology and pathophysiology was studied. Modeling methodology of human physiology was improved in order to build complex models based on acausal and object-oriented modeling techniques. Methods for conducting a parameter study (especially parameter estimation and parameter sweep) were introduced using grid computing and cloud computing technology. The identification of parameters gain substantial speedup by utilizing cloud computing deployment when performed on medium complex models of...
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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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Using of non-invasive cardiac imaging for precise evaluation of atrium size and prediction of atrial wall fibrosis in patients with atrial fibrillation
Fingrová, Zdeňka ; Havránek, Štěpán (advisor) ; Kittnar, Otomar (referee) ; Skála, Tomáš (referee)
Atrial fibrillation is the most prevalent arrhythmia worldwide and remains one of the major causes of morbidity and mortality. Atrial fibrillation is an arrhythmia that has a various etiology and takes number of clinical forms. Due to the heterogenity of atrial fibrillation, it is necessary to individualize the optimal treatment strategy, ie conservative pharmacological therapy or interventional therapy as catheter ablation. Inncorrect indication of catheter ablation of atrial fibrillation leads to low success rate of the procedure and increases the risk of the procedure. The success rate of catheter ablation of atrial fibrillation depends on many clinical parameters, including the size and volume of the left atrium and the presence of pathological tissue in the atrial myocardium. In everyday practice, echocardiography (2D-echocardiography) is the most dominant method in estimation of the left atrial parameters, for it's simplicity, non- invasiveness, financial costs and the absence of ionizing radiation. Different methods for assesment of left atrial parameters are cardiac CT, cardiac magnetic resonance imaging and methods of 3-D echocardiography or 3-D angiography. The results of the present studies show that in patients with non-valvular atrial fibrillation who are indicated for catheter...
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Biomechanical model of interaction between ventilation and hemodynamics induced by mechanical ventilation
Otáhal, Michal ; Kittnar, Otomar (advisor) ; Maršík, František (referee) ; Dostál, Pavel (referee)
MUDr. Michal Otáhal Biomechanický model interakce oběhu a ventilace za podmínek UPV Abstract: Conventional mechanical ventilation provides gas exchange in conditions of respiratory failure by application positive airway pressure in the respiratory system. Due to the significant change in pressure conditions inside the thorax during conventional artificial ventilation the circulation can be significantly affected. Recruitment maneuver (RM) techniques can be a part of ventilation strategy in patients with the Acute Respiratory Distress Syndrome (ARDS), that are used to re-aerate collapsed parts of the lung parenchyma. During these RMs a significantly higher airway pressure is used than in protective ventilation strategy, which can limit the flow through the lung capillary network and can significantly affect the systemic hemodynamics of the patient. The aim of this work was to develop an optimized animation model of ARDS, then to compare the influence that has the application of different types of recruitment maneuvers on hemodynamics and to create a biomechanical simulation model of interaction and blood circulation and its verification with data obtained during the implementation of different types of RM in the experimental animal ARDS model. Results from the experimental animal model and simulations...
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Regional flow and number of microembolisms in the common carotid artery at different levels of hemodynamics controlled by VA-ECMO.
Janák, David ; Kittnar, Otomar (advisor) ; Danzig, Vilém (referee) ; Bešík, Josef (referee)
Extracorporeal membrane oxygenation (ECMO) is a method that allows extracorporeal life support in potentially reversible life-threatening conditions affecting the heart or lungs which are refractory to conventional treatment. Depending on the parameters of its setting, this method affects the haemodynamics of the cardiovascular system and the perfusion of the target organ. From the point of view of its character, the necessity for invasive application, and the function thereof in the conditions of the cardiovascular system, ECMO is regarded as a risky method accompanied by a number of complications. Among the critical complications are thromboembolic complications affecting the central nervous system (CNS) and haemorrhagic complications. The goal of this paper is to present and verify the prerequisites for the formation of periprocedural embolisms affecting the CNS and to evaluate the regional haemodynamics of the CNS. This is done by analysing the presence of embolisms and by analysing the parameters of blood flow rates in the right common carotid artery (arteria carotis communis-ACC) and the corresponding oxygenation of the brain tissue during various flow rate parameters generated by the ECMO support on induced heart failure in a biological porcine model. In the first section of the paper, 8...
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Electrical stability of the heart during hypothermia-induced potassium plasmatic level changes and after modulation of the autonomic nervous system by renal denervation.
Kudlička, Jaroslav ; Kittnar, Otomar (advisor) ; Nováková, Marie (referee) ; Danzig, Vilém (referee)
Malignant ventricular arrhythmias are a common cause of sudden cardiac death. Moderate therapeutic hypothermia (MTH) is routinely used in post-resuscitation care for anticipated neuroprotective effects. However, the safety of MTH in terms of the electrical stability of the heart has not been satisfactorily proved yet. Also, the increased sympathetic tone in patients with heart failure contributes to a higher incidence of malignant ventricular arrhythmias. The aim of this work was to verify the safety of MTH as regards the inducibility of ventricular fibrillation (VF) in the pig biomodel, especially in relation to spontaneous changes in the kalemia and QT interval. Furthermore, we assumed that renal denervation (RDN) could reduce the inducibility of VF. In the first part of the thesis, the extracorporeal cooling was introduced in fully anesthetized swine (n = 6) to provide MTH. Inducibility of VF was studied by programmed ventricular stimulation (8 basic stimuli with up to 4 extrastimuli) three times in each biomodel under the following conditions: during normothermia (NT), after reaching the core temperature 32 řC (HT) and after another 60 minutes of stable hypothermia (HT60). VF inducibility, effective ventricular refractory period (ERP), QTc interval, and potassium plasma level were measured. In...
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Changes of the electric field of the heart in disorders of glucose metabolism and ways of influencing them by correction of impaired autonomic nervous regulation
Fialová, Elena ; Kittnar, Otomar (advisor) ; Danzig, Vilém (referee) ; Ošťádal, Petr (referee)
Diabetes mellitus (DM) is not just a simple metabolic disorder, however, it is considered to be a cardiovascular disease of a metabolic origin. This is apparent especially when speaking about type 2 diabetes (DM II). Patients with DM have a high occurrence of vegetative nervous system (VNS) disorders that manifest themselves as an increased activity of the sympathetic nervous system that correlates with peripheral autonomic neuropathy and is considered to be the major pathophysiological mechanism for the development of DM II. The objective of our study was to determine whether a comprehensive spa treatment (ST) may affect the level of the sympathetic tone of patients suffering from DM II. As an indicator of the sympathetic tone, selected electrocardiographic parameters derived from the HRV, microvolt T-wave alternans, and microvolt R-wave alternans were evaluated. The electrophysiological examination of patients was performed before and after a three-week spa treatment using the KARDiVAR system. The method is used to examine the current state of the autonomic nervous system and carry out an analysis of risk factors and adaptive capabilities of the organism. The results showed favorable changes in DM II patients after the ST, primarily in terms of reduced sympathetic adrenal system activity,...
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Utilization of GRID technology in processing of medical information
Kulhánek, Tomáš ; Šárek, Milan (advisor) ; Kittnar, Otomar (referee) ; Anjum, Ashiq (referee)
This thesis focuses on selected areas of biomedical research in order to benefit from current computational infrastructures established in scientific community in european and global area. The theory of computation, parallelism and distributed computing, with focus on grid computing and cloud computing, is briefly introduced. Exchange of medical images was studied and a seamless integration of grid-based PACS system was established with the current distributed system in order to share DICOM medical images. Voice science was studied and access to real-time voice analysis application via remote desktop technology was introduced using customized protocol to transfer sound recording. This brings a possibility to access current legacy application remotely by voice specialists. The systems biology approach within domain of human physiology and pathophysiology was studied. Modeling methodology of human physiology was improved in order to build complex models based on acausal and object-oriented modeling techniques. Methods for conducting a parameter study (especially parameter estimation and parameter sweep) were introduced using grid computing and cloud computing technology. The identification of parameters gain substantial speedup by utilizing cloud computing deployment when performed on medium complex models of...
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The stress response to cardiac catheterisation. The concentration of stress markers of the hypothalamic-pituitary-adrenal axis
Skarlandtová, Hana ; Kittnar, Otomar (advisor) ; Gregor, Pavel (referee) ; Svoboda, Miroslav (referee)
In our study, we analyzed four stress markers (cortisol, cortisone, DHEA and DHEAS) in blood serum in young sows using minimally invasive heart catheterisation as the stress factor. The marker levels were assessed in four defined periods of the experiment, beginning with the baseline level on the day before intervention (1), the second period was after the introduction of anaesthesia (2), the third was after conducting tissue stimulation or ablation (3), and the final period was after the end of the catheterisation (4). Cortisol and cortisone were detected using HPLC method, DHEA(S) by commercial kits. For statistical analyses non-parametric tests were used (due to non standard Gaussian data distribution). In our study we arranged these experiments: 1. Diurnal variability in these markers concentration during heart catheterisation was tested. 2. Are there differences between stress markers concentration the day before experiment (sampling 1) and in the day of the catheterisation (samplings 2, 3, 4)? 3. Are there differences between these markers concentration during operation (the first sampling was excluded)? 4. The cortisol/cortisone ratio was calculated. We found only minimal statistical differences in studied markers between the morning and afternoon group (p > 0.05) in experiment 1. For tested...
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