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Development of cardiovascular system function in patients with a functionally single ventricle
Materna, Ondřej ; Janoušek, Jan (advisor) ; Klásková, Eva (referee) ; Urbanová, Zuzana (referee)
Development of cardiovascular system function in patients with a functionally single ventricle. Abstract Total cavopulmonary connection (TCPC) is the only possible surgical palliative procedure in patients with a functionally single ventricle. It consists of the stepwise anastomosis of both caval veins with pulmonary arteries, creating a unique situation of so-called Fontan circulation, where the separation of the pulmonary and systemic circuit is traded for chronically elevated systemic venous pressure and impaired cardiac output increase during exercise. We aimed to evaluate long-term results and development of exercise capacity in the population of patients with TCPC in the Czech Republic, possible predictors of their survival and functional outcome, as well as analysis of permanent cardiac resynchronization as one of the new treatment options for dysfunction of the single ventricle. We present a retrospective study of all consecutive patients in the Czech Republic identified in the nationwide single-centre institutional database and matched with the National Death Registry and Cardiovascular Intervention Registries. We proved that overall mean survival probability until composite end-point of death, TCPC take- down or indication for a heart transplant was 92.9 % at 20 years after the operation. TCPC...
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Deep learning based QRS delineator
Malina, Ondřej ; Ronzhina, Marina (referee) ; Smíšek, Radovan (advisor)
This thesis deals with the issue of automatic measurement of the duration of QRS complexes in ECG signals. Special emphasis is then placed on the possibility of automatic detection of QRS complexes while exciting cardiac tissue with a pacemaker. The content of this work is divided into four logical units, where the first part deals with the heart as an organ. It describes the origin and spread of excitement in the heart, its possible pathologies and their manifestations in ECG recording, it also deals with pacing and measuring ECG recording during simultaneous pacing. The second part of the thesis contains a brief introduction to the topic of machine and deep learning. The third part of the thesis contains a search of current approaches using methods based on deep learning to solve the detection of QRSd. The fourth part deals with the design and implementation of its own model of deep learning, able to detect the beginnings and ends of QRS complexes from ECG recordings. It describes the data preprocessing implemented in the MATLAB programming environment. The actual implementation of the model was performed in the Python using the PyTorch and NumPy moduls.
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Deep learning based QRS delineator
Malina, Ondřej ; Hejč, Jakub (referee) ; Smíšek, Radovan (advisor)
This thesis deals with the issue of automatic measurement of the duration of QRS complexes in ECG signals. Special emphasis is then placed on the possibility of automatic detection of QRS complexes while exciting cardiac tissue with a pacemaker. The content of this work is divided into four logical units, where the first part deals with the heart as an organ. It describes the origin and spread of excitement in the heart, its possible pathologies and their manifestations in ECG recording, it also deals with pacing and measuring ECG recording during simultaneous pacing. The second part of the thesis contains a brief introduction to the topic of machine and deep learning. The third part of the thesis contains a search of current approaches using methods based on deep learning to solve the detection of QRSd. The fourth part deals with the design and implementation of its own model of deep learning, able to detect the beginnings and ends of QRS complexes from ECG recordings. It describes the data preprocessing implemented in the MATLAB programming environment. The actual implementation of the model was performed in the Python using the PyTorch and NumPy moduls.
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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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The influence of pacemaker implantation on the patient´s life
HOLUBOVÁ, Kateřina
Bachelor thesis concerns with the issue of perception and effect of the pacemaker on patient and his life. The theoretical part deals with particular illnesses as indications to a permanent cardiac stimulation. It also describes individual examinations that a cardiological patient can undergo. Major category comprises of regime measures and recommendations on how to perform with a pacemaker. This category is systematically divided into specific spheres, in which a problem or a potential risk for the pacemaker as well as for the patient can arise. The practical, research part is done with a help of a qualitative research survey with a half-structured interview as a tool of information obtaining. The questions were drawn in order to cover the life before pacemaker´s implantation, during the stay in hospital and to catch the following adaptation to the pacemaker and to this reality. The research group comprised of 10 patients implanted 4 - 8 months before the survey. The aim of this thesis was to find out what effect the pacemaker and his implantation have. The results show the effect of pacemaker mainly in connection with complications experienced. Our respondents admitted that adaptation to the pacemaker took them some time. The exception was the respondent who did not accept the pacemaker, especially in connection with the feeling of the mechanism in the body and the visibility of the devices under the skin. From the interviews with the respondents, we clearly show that their lack of a brochure, information material about the risks associated with this problems. The results obtained and information collected lead to our decision to issue an informative leaflet for patients, which also became an output of the bachelor thesis. This booklet contains the experiences of patients who have already had a pacemaker implantation.
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Microcontroler based On Demand Pacemaker
Daniš, Václav ; Balogh, Jaroslav (referee) ; Sekora, Jiří (advisor)
Pacemakers have nowadays become an inseparable part of treatment in a wide range of cardiovascular diseases. The topic of this bachelors degree paper refers to and proposes the implementation of a functional type of ´On Demand´ pacemaker controlled by a microcontroller. The introductory chapters focus on a more detailed, theoretical familiarization with the complex issues of permanent heart cardiostimulation. In addition to the actual theory of pacemakers and cardiostimulation, the chapters also include those significant historical aspects in the evolution of permanent cardiostimulation, the basic structures of heart anatomy and the transmission system of the heart. Also included are the recording of heart activity and ECG analysis, both physiological and pathological. In the practical part of the paper I deal with the ´On Demand´ pacemaker controlled by a microcontroller with a firm (solid, strong, steady, fixed) repeating frequency inhibited by the R wave. Subsequently, a proposed system for its implementation is created. The next step is the creation of a scheme for the electrical connections and composition of the microcontroller programme. The final part illustrates the implementation of the model of the pacemaker itself, preceded by a verification of the efficacy of the connections in a non-solder field.
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The dynamics of changes of leads' technical parameters during stimulation
Kulík, Tomáš ; Chmelař, Milan (referee) ; Rozman, Jiří (advisor)
The main theme of the thesis is the dynamics of changes of leads’ technical parameters during stimulation. The thesis is dealt with statistical analysis of clinical dates and investigation of time variability of chosen stimulation parameters during the time of implantation to 3 years after surgical intervention. The document consists of theoretical parts about cardiac pacing and one’s own project of statistical solution according to submission.
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Removal of pacing spikes from the electrocardiographic signal
Smíšek, Radovan ; Plešinger,, Filip (referee) ; Postránecká, Tereza (advisor)
The goal of this thesis is to detect pacing pulses in ultra high-frequency ECG so as to remove these pacing pulses. It makes evaluation of higher frequency components of QRS complex possible. This evaluation is impossible while pacing pulses are present. Chosen issue is solved using heuristic algorithm. Algorithm uses spacing of signal by line in the area which is not influenced by pacing pulses. Subsequently this line is made longer and using differences between line and signal (or another rules) edges of pacing pulses are detected. The top of the stimulation tip is detected by thresholding envelope of original signal´s first difference. More algorithms are tested in this thesis. Several methods of removing pacing pulses are suggested in thesis. Envelopes of high-frequency components are created. Envelopes are analyzed subsequently and suggested methods of removing pacing pulses are compared on the basis of these analysis. Finally the detection efficiency is evaluated.
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ECG signal classification
Smělý, Tomáš ; Harabiš, Vratislav (referee) ; Hrubeš, Jan (advisor)
This thesis deals with classification of different types of time courses of ECG signals. Main objective was to recognize the normal cycles and several forms of arrhythmia and to classify the exact types of them. Classification has been done with usage of algorithms of Neural Networks in Matlab program, with its add-on (Neural Network Toolbox). The result of this thesis is application, which makes possible to load an ECG signal, pre-process it and classify its each cycle into five classes. Percentage results of this classification are in the conclusion of this thesis.
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