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The effect of new synthetized drugs on electrical activity of rat isolated heart
Korčáková, Ivona ; Janoušek, Oto (referee) ; Ronzhina, Marina (advisor)
This thesis deals with the influence of the newly synthesized drug on the electrical activity of the isolated heart of rat. Part of the thesis is a theoretical analysis of the use laboratory animals in experiments and ethical aspects related to the use of laboratory animals. There is also an analysis of drug testing, test substances, electrocardiography and methods used to detect and measure ECG signal. The two algorithms used for the QT interval are automated. The QT interval is the main indicator of cardiotoxicity and is considered to be the gold standard in evaluating the effect of the drug. In the practical part the ECG records obtained at the Faculty of Medicine at Masaryk University in Brno are processed. These records are dimmed manually and automatically. The manual dimming was consulted with a specialist in cardiography and statistically processed. Statistical processing served to compare with the results of the automatic ECG measurement. The algorithm is used to automate the measurement, and the results are compared with the reference points obtained from cardiology experts and manual measurement results. This work serves as a pilot study for the development and testing of a new active substance.
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Evaluation of the antineoplastic treatment effects on heart electrical activity in experimental telemetric study
Beňková, Daniela ; Janoušek, Oto (referee) ; Ronzhina, Marina (advisor)
This master´s thesis deals with the analysis of experimental telemetrical ECG records with intention to determine the long-term influence of anticancer drug sunitinib on the electrical activity of heart. A laboratory rat was chosen as a model organism for the experimental study carried out at the Department of Physiology at Faculty of Medicine, Masaryk university. The sunitinib was applied to the rats at an early age and the ECG was measured with a 20-week delay using the Stellar telemetry system. To measure the effect of sunitinib on the electrical activity of the heart chambers, an analysis of the duration of the RR and QT interval and the width of the QRS complex was chosen. These parameters were detected by the wavelet transform method. Statistical analysis was performed using nonparametric tests - the Wilcoxon signed rank test, the MannWhitney test and the Friedman Test. The obtained results suggest that the use of sunitinib has no long-term effect on the observed parameters for the chosen animal model. After extension of the study, the results obtained could contribute to assess the effect of drugs on electrical activity of the human heart several decades after sunitinib treatment termination.
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Processing of electrocardiograms
Princ, Martin ; Vítek, Martin (referee) ; Kolářová, Jana (advisor)
This work concerns with problems of the QT sequences detection in ECG signal. The first part introduces electrophysiology of heart and his electrical manifestation. For main detection were used two algorithms, which were afterwards modified and programmed in Matlab. The work includes developed custom applications for measurement and evaluation of the length of QT interval. The final lengths of the QT interval, which we got from this two methods, were compared with reference length.
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METHODS FOR DETECTION AND CLASSIFICATION IN ECG ANALYSIS
Kičmerová, Dina ; Kremláček,, Jan (referee) ; Sovka, Pavel (referee) ; Provazník, Ivo (advisor)
První část práce je zaměřena na měření QT intervalu. QT interval může být použit k hodnocení kardiovaskulárního zdraví pacientů a detekovat potenciální abnormality. QT interval je měřen od začátku QRS komplexu až po konec T vlny. Nicméně, měření konce T vlny je často vysoce subjektivní a jeho verifikace je obtížná. Představujeme dvě metody měření QT intervalu - vlnkovou a šablonovou metodu. Metody byly porovnány mezi sebou a testovány na QT databázi. Druhá část práce je zaměřena na modelování arytmických signálů McSharryho modelem následována klasifikací s použitím umělých neuronových sítí. Metoda používá předzpracování signálů lineární aproximací a shlukování lineárních segmentů pro stanovení počátečních parametrů McSharryho modelu. Byly použity EKG signály standardní MIT/BIH Arrhythmia Databáze. Modelování bylo testováno na celé databázi a svodu MLII (modifikovaný svod II). Všechny signály mohou být modelovány 10 Gaussovými funkcemi bez významného zkreslení. Třetí část práce představuje klasifikaci EKG do dvou tříd. Předčasné komorové kontrakce (PVC) mají vysoký význam při hodnocení a predikci život ohrožujících ventrikulárních arytmií. Představujeme algoritmus pro detekci předčasných komorových kontrakcí s použitím McSharryho modelu a neuronových sítí. Signály modelované 30 Gaussovými parametry byly předloženy na vstup umělé neuronové sítě. Použitý vícevrstvý perceptron dosáhl klasifikační úspěšnosti 93,10% pro předčasné komorové kontrakce (PVC) a 96,43% pro normální stahy.
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Evaluation of the antineoplastic treatment effects on heart electrical activity in experimental telemetric study
Beňková, Daniela ; Janoušek, Oto (referee) ; Ronzhina, Marina (advisor)
This master´s thesis deals with the analysis of experimental telemetrical ECG records with intention to determine the long-term influence of anticancer drug sunitinib on the electrical activity of heart. A laboratory rat was chosen as a model organism for the experimental study carried out at the Department of Physiology at Faculty of Medicine, Masaryk university. The sunitinib was applied to the rats at an early age and the ECG was measured with a 20-week delay using the Stellar telemetry system. To measure the effect of sunitinib on the electrical activity of the heart chambers, an analysis of the duration of the RR and QT interval and the width of the QRS complex was chosen. These parameters were detected by the wavelet transform method. Statistical analysis was performed using nonparametric tests - the Wilcoxon signed rank test, the MannWhitney test and the Friedman Test. The obtained results suggest that the use of sunitinib has no long-term effect on the observed parameters for the chosen animal model. After extension of the study, the results obtained could contribute to assess the effect of drugs on electrical activity of the human heart several decades after sunitinib treatment termination.
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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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The effect of new synthetized drugs on electrical activity of rat isolated heart
Korčáková, Ivona ; Janoušek, Oto (referee) ; Ronzhina, Marina (advisor)
This thesis deals with the influence of the newly synthesized drug on the electrical activity of the isolated heart of rat. Part of the thesis is a theoretical analysis of the use laboratory animals in experiments and ethical aspects related to the use of laboratory animals. There is also an analysis of drug testing, test substances, electrocardiography and methods used to detect and measure ECG signal. The two algorithms used for the QT interval are automated. The QT interval is the main indicator of cardiotoxicity and is considered to be the gold standard in evaluating the effect of the drug. In the practical part the ECG records obtained at the Faculty of Medicine at Masaryk University in Brno are processed. These records are dimmed manually and automatically. The manual dimming was consulted with a specialist in cardiography and statistically processed. Statistical processing served to compare with the results of the automatic ECG measurement. The algorithm is used to automate the measurement, and the results are compared with the reference points obtained from cardiology experts and manual measurement results. This work serves as a pilot study for the development and testing of a new active substance.
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METHODS FOR DETECTION AND CLASSIFICATION IN ECG ANALYSIS
Kičmerová, Dina ; Kremláček,, Jan (referee) ; Sovka, Pavel (referee) ; Provazník, Ivo (advisor)
První část práce je zaměřena na měření QT intervalu. QT interval může být použit k hodnocení kardiovaskulárního zdraví pacientů a detekovat potenciální abnormality. QT interval je měřen od začátku QRS komplexu až po konec T vlny. Nicméně, měření konce T vlny je často vysoce subjektivní a jeho verifikace je obtížná. Představujeme dvě metody měření QT intervalu - vlnkovou a šablonovou metodu. Metody byly porovnány mezi sebou a testovány na QT databázi. Druhá část práce je zaměřena na modelování arytmických signálů McSharryho modelem následována klasifikací s použitím umělých neuronových sítí. Metoda používá předzpracování signálů lineární aproximací a shlukování lineárních segmentů pro stanovení počátečních parametrů McSharryho modelu. Byly použity EKG signály standardní MIT/BIH Arrhythmia Databáze. Modelování bylo testováno na celé databázi a svodu MLII (modifikovaný svod II). Všechny signály mohou být modelovány 10 Gaussovými funkcemi bez významného zkreslení. Třetí část práce představuje klasifikaci EKG do dvou tříd. Předčasné komorové kontrakce (PVC) mají vysoký význam při hodnocení a predikci život ohrožujících ventrikulárních arytmií. Představujeme algoritmus pro detekci předčasných komorových kontrakcí s použitím McSharryho modelu a neuronových sítí. Signály modelované 30 Gaussovými parametry byly předloženy na vstup umělé neuronové sítě. Použitý vícevrstvý perceptron dosáhl klasifikační úspěšnosti 93,10% pro předčasné komorové kontrakce (PVC) a 96,43% pro normální stahy.
|
|
|
Processing of electrocardiograms
Princ, Martin ; Vítek, Martin (referee) ; Kolářová, Jana (advisor)
This work concerns with problems of the QT sequences detection in ECG signal. The first part introduces electrophysiology of heart and his electrical manifestation. For main detection were used two algorithms, which were afterwards modified and programmed in Matlab. The work includes developed custom applications for measurement and evaluation of the length of QT interval. The final lengths of the QT interval, which we got from this two methods, were compared with reference length.
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