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Effect of pulsatility of blood flow on parametres of vascular damage in patients with mechanical circulatory support
Ivák, Peter ; Netuka, Ivan (advisor) ; Štádler, Petr (referee) ; Ošťádal, Petr (referee)
Ventricular assist devices are an important therapeutic modality in advanced surgical therapy of end-stage heart failure. Devices mainly used until recently generate primarily non- pulsatile blood flow. Despite indisputable clinical success of this therapy, we encounter complications specific to the devices with continuous flow. Complications are mostly attributed to increased shear stress and changes in blood vessels, blood elements and endothelium. The aim of this study was to determine the effect of continuous blood flow on the vasculature and blood elements by longitudinal monitoring of selected biomarkers of vascular health. During the study we monitored circulating microparticles, endothelial progenitor cells and stem cells and examined degradation dynamics of von Willebrand factor and its function. Results obtained in our study confirm the hypothesis of changes in the dynamics of studied markers dependent on the change of characteristics of blood flow. The possible negative effect of continuous flow on monitored parameters was observed in tracked period. In degradation of the high molecular weight von Willebrand factor multimers the probable positive effect of arteficial pulsatility was observed. Further research can provide important data for the development of specific characteristics...
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The importance of genetic testing in prevention of bleeding complications of invasive procedures in cardiology
Sionová, Magdalena ; Moťovská, Zuzana (advisor) ; Ošťádal, Petr (referee) ; Pudil, Radek (referee)
Background: Periprocedural bleeding is the most common complication related to coronary angiography (CAG) and percutaneous coronary intervention (PCI) and it is associated with worse short-term and long-term prognosis. Determining risk factors and genetic variations associated with increased bleeding risk may improve use of avoidance bleeding strategies in prevention of bleeding. Aim: The aim of our study was to a) identify independent risk factors (of the baseline characteristics, clinical, laboratory a procedural data) associated with a higher risk of periprocedural bleeding b) to validate predictive value of CRUSADE and NCDR bleeding risk stratification algorithms c) to analyze the association between the presence of selected single nucleotide polymorphisms of key platelet proteins (GPIa, GPVI, P2Y12, COX-1) and the risk of periprocedural bleeding. Methods: The study included 73 patients with acute or chronic ischemic heart disease who developed bleeding complication within 30 days after invasive procedure (CAG/PCI). The control group consisted of 331 patients without bleeding. Baseline characteristics, clinical state at admission, laboratory data (creatinine, blood count, INR) and procedural data were evaluated. The CRUSADE and NCDR algorithms for bleeding risk were retrospectively applied on both...
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Allooimmunosensitization in left ventricular assist device recipients and impact on post-transplantation outcome
Urban, Marián ; Netuka, Ivan (advisor) ; Ošťádal, Petr (referee) ; Mrázek, František (referee)
Background: In recent years mechanical circulatory assist devices became an established option in bridging patients with refractory heart failure to heart transplantation. One of the alleged limitations of mechanical devices is a high degree of antibody production with possible deleterious effect on subsequent heart transplantation outcome. Aim: The main goal of this study is to assess the role of antibodies on the outcome of surgical treatment of patients with end- stage heart failure. Method: Firstly, we present a literature review on the current state of knowledge of possible immunologic mechanisms involved in antibody production in left ventricular assist device (LVAD) recipients, new methods of antibody detection, desensitization strategies and overview of published evidence assessing the impact of sensitization on post-transplantation outcome. In the experimental part of our study we prospectively evaluated the presence of anti-Angiotensin II Type 1 Receptor (AT1R) antibodies in 83 Heart Mate II (HMII) recipients who were implanted at our institution between 2008 and 2012 and survived the first 60 days. On-device survival and device malfunction, major infection, major bleeding and neurologic dysfunction were compared between antibody positive and antibody negative recipients. Out of a total...
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Treatment of pulmonary hypertension affect the metabolism of cyclic guanosine monophosphate
Al-Hiti, Hikmet ; Kettner, Jiří (advisor) ; Ošťádal, Petr (referee) ; Goncalvesová, Eva (referee)
Chronic damage to pulmonary vessels leads to pulmonary hypertension (PH). Different forms of PH are quite frequent and are associated with significant morbidity and mortality. The treatment of PH is most successful, if its cause can be identified and removed before irreversible damage to the pulmonary vascular bed occurs. For patients, in whom the elimination of the underlying cause is not possible or where the cause is unknown, the treatment is aimed at reduction of pulmonary vascular resistance and improvement of cardiac and circulatory response to pressure overload of the right ventricle. One option for the PH treatment is modification of metabolism of cyclic guanosine monophosphate (GMP), which is the second messenger of nitric oxide and induces vascular vasodilation. Cyclic GMP is degraded by phosphodiesterases (PDE 5). In the clinical part, we tested the hypothesis that acute inhibition of PDE5 by sildenafil provides more selective pulmonary vasodilation than high doses of prostaglandin E1 (PGE1). The study showed that the vasodilator effects of sildenafil on pulmonary circulation is more pronounced than in the systemic circulation and that sildenafil had a greater ability to detect reversible component precapillary PH due to advanced chronic heart failure than PGE1. The aim of our...
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Mild therapeutical hypothermia and oxidative stress after cardiac arrest
Krüger, Andreas ; Ošťádal, Petr (advisor) ; Vízek, Martin (referee) ; Rokyta, Richard (referee)
Successfull cardiopulmonary resuscitation is an essential life-saving tool; nevertheless, general ischemia during cardiac arrest may trigger different pathways that could turn even into a fatal damage; this condition is called post-cardiac arrest syndrome. It has been repeatedly shown that oxidative stress (OS) plays one of the key roles in the development of ischemia-reperfusion injury. However, current evidence on the possible participation of OS in the pathogenesis of post-cardiac arrest syndrome is insufficient. We tested following hypotheses: (i) ischaemia-reperfusion injury after cardiac arrest is accompanied by OS and (ii) mild therapeutical hypothermia decreases OS cardiac arrest. In the experimental part of our work we studied the effects of hypothermia and normothermia on hemodynamic parameters, markers of organ damage and on the OS burden in porcine model of cardiac arrest. Furthermore, we compared the effects of hypothermia with ischaemic postconditioning and nitric oxide administration in the porcine model of extracorporeal cardiopulmonary resuscitation. We found protective effects of hypothermia on all major endpoints including OS in comparison with normothermia; moreover, hypothermia improved also selected variables compared to ischemic postconditioning and nitric oxide. In the...
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Left ventricle remodeling in patients with primary aldosteronism and essential hypertension
Indra, Tomáš ; Holaj, Robert (advisor) ; Ošťádal, Petr (referee) ; Paleček, Tomáš (referee)
Myocardial damage is one of the most serious consequences of arterial hypertension. Changes in the heart structure and function develop not only due to pressure overload itself, but many other hemodynamic and neurohumoral factors contribute to their formation. Our work has compared echocardiohraphic strucutural anf functional changes of the left ventricle, caused by essential hypertension and hypertension associated with primary aldosteronism (PA) as the most common reason for secondary hypertension. The first part of our work focused on the differences in left ventricle geometry in men with PA and essential hypertension after separating it's low-renin form (where, similarly to PA, the plasma volume expansion was considered to have the dominant effect on left ventricle remodelation). In men with low-renin forms of hypertension including PA, we observed greater both endsystolic and enddiastolic diameter of the left ventricle, lower relative wall thickness and more frequent eccentric type of hypertrophy when compared to essential hypertensives with normal renin levels. Whereas left ventricle cavity diameters were positively correlated to aldosterone levels, wall thicknesses were associated mainly with hypertension severity expressed as an average 24hour blood pressure and number of antihypertensives....
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New aproaches to myocardial atrophy attenuation after mechanical unloading - Experimental study of heterotopic heart transplantation in rats
Pokorný, Martin ; Malý, Jiří (advisor) ; Ošťádal, Petr (referee) ; Rohn, Vilém (referee)
Cardiac atrophy, as a result of a long term mechanical unloading observed in patients treated with mechanical circulatory supports, represents a substantial obstacle in cardiac recovery. The first aim of this thesis was to evaluate the course of unloading-induced cardiac atrophy in healthy and failing heart. Mechanical unloading was studied in an experimental model of heterotopic heart transplantation in rats. Heart failure was experimentally induced by chronic volume overload achieved by creation of aorto-caval fistula. The second aim of this thesis was to discover if dietary induced increase in fatty acids concentration in heart tissue, specifically myristic, palmitic and palmitooleic, that are believed to promote physiological heart growth, could attenuate the course of cardiac atrophy. The third aim of this thesis was to examine if increased isovolumic loading obtained by intraventricular implantation of newly designed spring expander would attenuate the development of cardiac atrophy. The level of cardiac atrophy was evaluated as the weight loss of the heterotopically tranplanted heart compared to the control heart on days 7, 14, 21 and 28 after heterotopic transplantation. The cardiomyocyte width and the level of cardiac fibrosis was studied simultaneously. Mechanical unloading following heterotopic...
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Cardiac Pacing Hemodynamics
Ulč, Ivan ; Vančura, Vlastimil (advisor) ; Mayer, Otto (referee) ; Ošťádal, Petr (referee)
(EN) Cardiac pacing is the only established treatment method of bradyarrhythmias. Most patients indicated for cardiac pacing need to have one lead implanted in the right ventricle. Activation sequence of the left ventricle during right ventricular pacing resembles the activation sequence in patients with left bundle branch block. When the proportion of paced cycles in the right ventricle reaches significant level, 10-20 % of patients develop pacing induced cardiomyopathy. Direct causal relationship with right ventricular pacing is supported by the improvement of subjective symptoms and objective parameters of the left ventricular function after the upgrade to cardiac resynchronization therapy (CRT). In patients with preexisting heart failure with reduced left ventricular ejection fraction, the best prevention of heart failure worsening is to implant CRT when antibradycardic indication to the right ventricular pacing occurs. In patients with normal or near normal left ventricular function, the situation is more problematic. CRT implantation in all patients with supposed high proportion of right ventricular paced cycles is not only more expensive, but also imposes higher demands on implanting centers and increases the occurrence of immediate as well as long-term complications which do not outweigh...
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Possibilities of organ protection after global ischemia during cardiac arrest.
Mudrochová, Hana ; Ošťádal, Petr (advisor) ; Rokyta, Richard (referee) ; Malý, Jiří (referee)
Successful cardiopulmonary resuscitation is the first step to rescue life during cardiac arrest. High mortality even after successful restoration of spontaneous circulation is substantially caused by patophysiological process associated with ischemia-reperfusion injury and it is widely called post-cardiac arrest syndrome (PCAS). There are many patophysiological mechanisms involved in the development and progress of this syndrom; the key role seems to play oxidative stress, triggering the activation cascade of systemic inflammatory reaction. In our study we have tested different possibilities of influencing the post-cardiac arrest syndrom. In the first experimental study we have compared the effect of mild therapeutic hypothermia with controlled normothermia on PCAS in a porcine model of cardiac arrest. In the second study we have compared in the same model the protective effects of mild therapeutic hypothermia, administration of nitric oxide and ischemic postconditioning. Results of the first experiment have revealed that mild therapeutic hypotermia is superior in the resuscitability, maintenance of blood pressure, oxidative stress suppression and organ damage protection than controlled normothermia. In the second experiment we have shown that neither nitric oxide administration, nor ischemic...
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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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