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Analysis of heart rhythm disturbances in fetuses
Tomek, Viktor ; Ošťádal, Bohuslav (advisor) ; Sedmera, David (referee) ; Calda, Pavel (referee)
Analysis of heart rhythm distrubances V.Tomek Abstract Objective: The dissertation was focused on prenatal cardiology. Prenatal cardiology is a relatively young field, which is focused on diagnosis and treatment of fetal heart. In the thesis, I focused on the issue of cardiac arrhythmias: pathophysiology, diagnosis and therapeutic management of prenatally heart rhythm disturbances. The most frequent type of prenatal arrhythmias are fetal isolated complete atrioventricular (AV) block and supraventricular tachycardia (SVT). Although these rhythm heart disorders are relatively rare, but can lead to heart failure and are important causes of fetal mortality. Methods: We performed measurement of mechanical atrioventricular conduction time intervals in human foetuses assessed by Doppler echocardiography and provided reference values. We compared reference values with foetuses of mothers with anti-SSA Ro/SSB La autoantibodies, being in risk of isolated congenital heart block development. We collaborated in a multinational, multicenter retrospective study of 175 fetuses diagnosed with AV block (2000 -2007) to analyse the influence of the treatment. We compared 2 treatment protocols (Prague and London) to find out the optimal treatment strategy of fetuses with supraventricular tachycardia. The severity of heart...
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Effect of temperature on arrhythmogenesis during heart development
Vostárek, František ; Sedmera, David (advisor) ; Tomek, Viktor (referee) ; Naňka, Ondřej (referee)
5 Abstract: Aims: The main objective of this work was to analyze in detail the effects of acute temperature changes on the function of isolated chick embryonic heart in vitro in comparison with natural conditions in ovo. Methods: The effects of temperature change (34 řC, 37 řC and 40 řC - hypo-, normo- and hyperthermia, respectively) on calcium dynamics in four days old isolated chick hearts in vitro were investigated by high-speed calcium optical imaging. For comparison and validation of in vitro measurements, experiments were also performed in ovo using videomicroscopy. Artificial electrical stimulation experiments were performed in vitro and in ovo to uncover conduction limits of different heart segments. Results: We observed almost linear dependence of sinus frequency on temperature in our temperature range. Sinus frequency during hypothermia and hyperthermia in vitro and in ovo changed about 20% in comparison with normothermia. We observed no significant changes in amplitude of calcium transients during temperature change to hypothermia but hyperthermia caused a significant decrease in amplitude of calcium transients (atria 35%, ventricles 38%). We observed a wide spectrum of arrhythmias, which occurred spontaneously even during normothermia in vitro. Occurrence of arrhythmias in vitro significantly...
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Effect of temperature on arrhythmogenesis during heart development
Vostárek, František ; Sedmera, David (advisor) ; Tomek, Viktor (referee) ; Naňka, Ondřej (referee)
5 Abstract: Aims: The main objective of this work was to analyze in detail the effects of acute temperature changes on the function of isolated chick embryonic heart in vitro in comparison with natural conditions in ovo. Methods: The effects of temperature change (34 řC, 37 řC and 40 řC - hypo-, normo- and hyperthermia, respectively) on calcium dynamics in four days old isolated chick hearts in vitro were investigated by high-speed calcium optical imaging. For comparison and validation of in vitro measurements, experiments were also performed in ovo using videomicroscopy. Artificial electrical stimulation experiments were performed in vitro and in ovo to uncover conduction limits of different heart segments. Results: We observed almost linear dependence of sinus frequency on temperature in our temperature range. Sinus frequency during hypothermia and hyperthermia in vitro and in ovo changed about 20% in comparison with normothermia. We observed no significant changes in amplitude of calcium transients during temperature change to hypothermia but hyperthermia caused a significant decrease in amplitude of calcium transients (atria 35%, ventricles 38%). We observed a wide spectrum of arrhythmias, which occurred spontaneously even during normothermia in vitro. Occurrence of arrhythmias in vitro significantly...
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Analysis of heart rhythm disturbances in fetuses
Tomek, Viktor ; Ošťádal, Bohuslav (advisor) ; Sedmera, David (referee) ; Calda, Pavel (referee)
Analysis of heart rhythm distrubances V.Tomek Abstract Objective: The dissertation was focused on prenatal cardiology. Prenatal cardiology is a relatively young field, which is focused on diagnosis and treatment of fetal heart. In the thesis, I focused on the issue of cardiac arrhythmias: pathophysiology, diagnosis and therapeutic management of prenatally heart rhythm disturbances. The most frequent type of prenatal arrhythmias are fetal isolated complete atrioventricular (AV) block and supraventricular tachycardia (SVT). Although these rhythm heart disorders are relatively rare, but can lead to heart failure and are important causes of fetal mortality. Methods: We performed measurement of mechanical atrioventricular conduction time intervals in human foetuses assessed by Doppler echocardiography and provided reference values. We compared reference values with foetuses of mothers with anti-SSA Ro/SSB La autoantibodies, being in risk of isolated congenital heart block development. We collaborated in a multinational, multicenter retrospective study of 175 fetuses diagnosed with AV block (2000 -2007) to analyse the influence of the treatment. We compared 2 treatment protocols (Prague and London) to find out the optimal treatment strategy of fetuses with supraventricular tachycardia. The severity of heart...
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