Zielsetzung: In dieser Machbarkeitsstudie evaluierten wir den aktuellen Standard der linksventrikulären Endomyokardbiopsie in einem Modellversuch. Wir entwickelten und überprüften mögliche Verbesserungen hinsichtlich ihrer Sicherheit und Punktionsgenauigkeit, indem wir eine steuerbare Schleuse und ein 3D Mapping-System zum Einsatz brachten. Hintergrund: Die Endomyokardbiopsie gilt als Goldstandard zur Diagnostik von Myokarditiden und Kardiomyopathien, da sie histochemische, histologische und molekularbiologische Analysen ermöglicht, die für eine korrekte Diagnose und Therapie wichtig sind. Die Methodik hat eine verhältnismäßig geringe Sensitivität und einen niedrigen negativen prädiktiven Wert, da das Myokard derzeit unter Röntgendurchleuchtung biopsiert wird, ohne eine genaue Orientierung im dreidimensionalen Raum oder eine Kenntnis der z.T. diskontinuierlich betroffenen Myokardareale zu haben (sogenannter „sampling error“). Methoden: Wir testeten die Steuerbarkeit und die Punktionsgenauigkeit der Endomyokardbiopsie im Modellversuch, indem wiederholt Biopsien von acht verschiedenen linksventrikulären Herzregionen genommen werden. In einer dreiarmigen Studie optimierten wir zum einen die invasiv-apparative Ausrüstung und zum anderen die verfügbare Bildgebungsmodalität. Der Kontrollversuch I repräsentiert eine Analyse des aktuellen Standards, da hier Biopsien mit konventionellen Führungskathetern unter Röntgendurchleuchtung erfolgen. Der Kontrollversuch II untersucht, ob mittels einer steuerbaren Schleuse unter konventioneller Bildgebung eine Verbesserung erzielt werden kann. Im dritten Teil der Studie wurde die Röntgendurchleuchtung durch ein 3D elektroanatomisches Mapping-System ersetzt. Hiermit kann erstmalig die Machbarkeit der Navigation einer steuerbaren Schleuse in einem 3D Mapping-System geprüft werden. Ergebnisse: Jeder der eingesetzten konventionellen Führungskatheter ist für die Biopsie einer bestimmten Herzregionen geeignet, jedoch hat die konventionelle Methodik bei wiederholten Messungen allgemein eine niedrige Präzision (JR 4.0 Führungskatheter: 17,4 ± 4 mm, AL 1.0 Führungskatheter: 18,7 ± 5,7 mm, EBU 3.5 Führungskatheter: 18,3 ± 8,2 mm). Durch den Einsatz der neu entwickelten steuerbaren Schleuse konnten einige der gewünschten Stellen zwar korrekter biopsiert werden, aber eine allgemein sichere Ansteuerung aller Positionen war damit noch nicht möglich (9,5 ± 5,8 mm). Die bildliche Darstellung der steuerbaren Schleuse im 3D Mapping-System gelang sehr gut, die Biopsiezange konnte mit der Schleuse leicht und mit einer höheren Präzision an fast alle gewünschten Herzregionen navigiert werden (3,6 ± 2 mm). Fazit: Die hier vorgelegte Machbarkeitsstudie zeigt, dass der Einsatz einer neuentwickelten steuerbaren Schleuse in Kombination mit einem 3D Mapping-System möglich und erfolgversprechend ist. Die Ergebnisse der Biopsien im elektroanatomischen Mapping-Versuch wiesen im Mittel eine deutlich geringere Abweichung beim wiederholten Ansteuern der jeweilig gewünschten Zielregion auf. Mittels der neuentwickelten Technik kann somit die Endomyokardbiopsie im Vergleich zum Standardverfahren präziser und mit einer potentiell höheren Patientensicherheit durchgeführt werden. / Objectives: In this proof of principle study we evaluated the current standard of leftventricular endomyocardial biopsy in an in-vitro test and developed and assessed improvements concerning safety and accurateness by making use of a steerable sheath and a 3D mapping system. Background: Endomyocardial biopsy represents the gold standard for diagnosing myocarditis and certain cardiomyopathies as it allows histology, immunhistochemistry and molecular biology studies which add to diagnosis and therapy. Nevertheless, the sensitivity and negative predictive value are comparatively low, as the biopsy is currently performed under fluorescence imaging without three-dimensional orientation and without exact knowledge of the partly discontinuously affected myocardium (so called sampling error). Methods: We tested the controllability and accuracy of endomyocardial biopsy in simulation tests by taking repetitive biopsies of 8 different leftventricular cardiac regions. In a three-arm study we first optimized the invasive technical equipment and second the available imaging technique. Control experiment one illustrates an analysis of the current standard as biopsies were taken with conventional diagnostic catheters under fluorescence imaging. In control experiment two the ability of improvement by the use of a steerable sheath under conventional imaging was checked. In part three of the study the fluorescence imaging was replaced by a three-dimensional electroanatomical mapping system. This simulation test represents a proof of principle for the first time navigation of a steerable sheath in a 3D mapping system. Results: Each tested standard guiding catheter was suited for biopsy of a particular part of the myocardium, although the conventional method in general proved to have a low accuracy in repetitive measurements (e.g. JR 4.0 guiding catheter: 17.4 ± 4 mm, AL 1.0 guiding catheter: 18.7 ± 5.7 mm, EBU 3.5 guiding catheter: 18.3 ± 8.2 mm). By the use of the newly developed steerable sheath in some requested regions the biopsy could be taken with higher precision, but a general save approach to all regions was still not possible (9.5 ± 5.8 mm). The electroanatomical mapping experiment revealed an excellent visualization of the steerable sheath in the 3D mapping system, allowing the biopsy forceps to be easily navigated by the sheath to almost all of the requested areas with higher precision (3.6 ± 2 mm). Conclusions: The use of a steerable sheath in combination with a 3D mapping system is possible and promising. The biopsy results of the electroanatomical mapping experiments showed on average clearly less deviation in repetitive approaches to the respective target areas. With the newly developed technique endomyocardial biopsy can be realized with higher accuracy and potentially more patient safety compared to the standard procedure.

The aim of this work was to study the expression of proteins involved in reactions in which harmful free radicals are degraded in an organism. was observed difference between the expression of selected myocardial proteins in non-influenced animals, animals who were treated with low dosage of morphine (0.1 mg/kg/day or 1 mg/kg/day), and animals administered high dosage of morphine (10 mg/kg/day). Low dosages were administered for 28 days and high dosage for 10 days. In addition, the effect of abstinence lasting one week was assessed after cessation of morphine administration (1 mg/kg/day). Morphine at low dosage (0.1 mg/kg/day) increased levels of glutathion peroxidase-1/2, which may be considered as one of the possible consequences of the ongoing oxidative stress. There were no significant differences in glutathion peroxidase-6 expression. Next aim of this work was to study the expression of antioxidant enzymes. These experiments were carried out on myocardial preparations from the animals treated with a constant dosage of morphine (10 mg/kg/day) for 10 days. Samples from these animals were used for measuring the total antioxidant capacity of the left and right ventricles. These samples were also used for determination of concentration of the oxidative stress marker 8-isoprostane. We also aimed to...

In der vorliegenden Arbeit wurde überprüft, ob sich sham-operierte Versuchsratten und gesunde Vergleichsratten in via Cine-Herz-MRT zu erfassenden Parametern signifkant unterscheiden. Hierzu wurden an einem Bruker 7 Tesla-Magnetresonanztomografen drei verschiedene Tiergruppen à 6 Tiere untersucht. Der erste Vergleich fand statt zwischen der gesunden Vergleichsgruppe und einer ähnlich schweren Shamtiergruppe, die sich in der 8. postoperativen Woche befand. Nachdem hier keinerlei signifikante Unterschiede zwischen den beiden Gruppen festzustellen waren, wurde der Vergleich ausgeweitet: Die Shamgruppe wurde zu einem frühen postoperativen Zeitpunkt (7-14 Tage postoperativ) ein zweites Mal mit der gesunden Gruppe verglichen. / The aim of this study was to test whether heart infarction sham operated rats were disparable from healthy rats by parameters captured by Cine MRI, gold standard of cardiac imaging. Therefore three groups of animals were examined, right and left ventricular myocardial parameters were determined and a comprehensive comparison of cardiac parameters was done. The first comparison was drawn between a healthy animal group and sham operated animals of nearly similar weight and age, 8 weeks after surgical procedure. Furthermore, we compared the same healthy animals’ group with remarkably younger sham animals quite shortly (in the 2nd week) after surgery.

Introduction: Magnetic resonance (MR) represents still the gold standard in myocardial imaging. There are some studies suggesting that the computed tomography (CT) might be a valid alternative for some patients (especially the ones who are unable to undergo MR). Aims: We had two aims. Aim number 1: To evaluate the ability of CT in the evaluation of delayed contrast enhancement (DCE) in patients with dilated cardiomyopathy. Aim number 2: To assess the possibilities of CT originally performed for a different indication in myocardial tissue characterization. Methods: Part 1: We prospectively enrolled 17 patients with dilated cardiomyopathy. All the patients underwent both cardiac CT and cardiac MR. We compared the findings of DCE on CT with the findings of DCE on MR. Part 2: We retrospectively evaluated 96 patients who underwent both CT for any indication and cardiac MR. We compared the findings of a hypodense area in the myocardium with the findings of DCE on MR. Results: Part 1: CT detected DCE in 3 patients and MR detected DCE in 6 patients. The agreement between both modalities was in v 82% cases (kappa 0.56). The sensitivity and specificity of CT were 50% and 100%, respectively and the positive predictive value was 100%. In patients with positive findings on CT, the localization of DCE was almost...

Adaptation to chronic hypoxia increases myocardial resistance to acute ischemia/reperfusion (I/R) injury, similarly to application of exogenous erythropoietin (EPO). Nevertheless, it is not known if EPO induced by chronic hypoxia plays a role in its cardioprotective mechanism. The aim of this study was to find out if protective effect of exogenous EPO adds up to protection offered by chronic hypoxia. Adult male mice (ICR) were adapted to intermittent hypobaric hypoxia 8 hours per day, 5 days per week for 5 weeks. The degree of hypoxia corresponded to 7000 metres. Control animals were housed for the same time in normoxic environment. Resistance to I/R injury was assessed according to size of myocardial infarction induced by 45-min global ischemia and 1-h reperfusion of the heart in vitro. Animals were treated 24 h before the experiment with 200 or 5000 U/kg EPO. Treatment with 200 U/kg EPO was sufficient to significantly limit infarct size in normoxic animals (33,56 ± 2,93 % vs. 25,71 ± 2,29 %). Hypoxic adaptation decreased infarct area to 23,49 ± 2,30%, but additive effect of EPO in hypoxic group was not detected. The results indicate that exogenous EPO employs the same cardioprotective mechanisms as adaptation to chronic intermittent hypoxia. Preliminary results indicate that repeated application of EPO...

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Cardiovascular diseases, particularly acute myocardial infarction, are one of the leading causes of death in developed countries. It is well known that adaptation to chronic intermittent hypobaric hypoxia (IHH) confers long-lasting cardiac protection against acute ischemia/reperfusion injury. Protein kinase C (PKC) appears to play a role in its cardioprotective mechanism since the administration of general PKC inhibitor completely abolished the improvement of ischemic tolerance in IHH hearts. However, the involvement of individual PKC isoforms remains unclear. Therefore, the primary aim of this study was to investigate the potential involvement of PKCδ and PKCε, the most prevalent PKC isoforms in rat heart, in the mechanism of IHH-induced cardioprotection. We showed that IHH up- regulated PKCδ protein in left ventricle, enhanced its phosphorylation on Ser643 and increased its co-localization with markers of mitochondrial and sarcolemmal membranes. PKCδ subcellular redistribution induced by IHH as well as the infarct size-limiting effect of IHH was reversed by acute treatment with PKCδ inhibitor rottlerin. These data support the view that PKCδ plays a significant role in IHH-induced cardioprotection. On the other hand, adaptation to IHH decreased the PKCε total protein level without affecting its...

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in Europe. Over 4 million people die from CVDs annually and another 11 million people develops CVDs every year. These numbers show that there is a need for better diagnostic, prognostic and predictive biomarkers and, more importantly, a need for new and more efficient drugs. Integral membrane proteins (IMPs) are ideal candidates for new drug targets. However, a study of IMPs represents a major challenge in current proteomics. This challenge is associated with the low abundance of IMPs, their low solubility in aqueous solvents and the absence of trypsin cleavage sites in their transmembrane segments. To overcome these issues, methods that selectively target either N-glycosylated extra-membrane segments (CSC, SPEG, N-glyco-FASP) or transmembrane segments (hpTC) were developed. In this thesis we employed a combination of two N-glyco-capture methods (SPEG and N-glyco-FASP) performed on two different samples (membrane-enriched fraction and total tissue lysate) with analysis of membrane-embedded IMP segments by hpTC and with standard non-targeted "detergent+trypsin" approach to analyze rat myocardial membrane proteome. We also performed an evaluation of employed methods for preparation of membrane fraction by western blot...

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.