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Function of systemic right ventricle after atrial correction of transposition of great arteries - longitudinal follow-up and impact on exercise capacity
Frank Antonová, Petra ; Rohn, Vilém (advisor) ; Linhartová, Kateřina (referee) ; Pudil, Radek (referee)
Function of systemic right ventricle after atrial correction of transposition of great arteries - longitudinal follow-up and impact on exercise capacity Abstract Maximal oxygen uptake during cardiopulmonary exercise test determines decision about pregnancy, therapeutic measures and timing of surgery and heart transplantation. Atrial correction of transposition of great arteries places right ventricle in the systemic positon. The aim of our work was to assess relation of parameters of function of systemic right ventricle to maximal oxygen uptake. 86 patients after Senning correction were subjected to testing of NYHA class, blood tests of NT-proBNP, Holter monitoring and cardiopulmonary exercise test. Systolic function of right ventricle was assessed semiquantitatively by echocardiography and precisely calculated by heart MRI. Maximal oxygen uptake was not associated with NYHA, NT-proBNP nor systolic function of systemic right and subpulmonary left ventricles. The only parameter associated with VO2max was heart rate reserve. Systolic function of the systemic right ventricle is likely only one integral part of a more complex haemodynamic mechanism of total heart output and its increase during exercise. In the second part of our study we aimed to ascertain long term mortality of all patients after atrial...
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Prognostic factors of surgical treatment of chronic thromboembolic pulmonary hypertension
Nižnanský, Matúš ; Lindner, Jaroslav (advisor) ; Rohn, Vilém (referee) ; Pudil, Radek (referee)
Chronic thromboembolic pulmonary hypertension (CTEPH) is a disease characterized by increased pulmonary artery pressure. It is caused by intraluminal thrombi organisation, stenoses and occlusions of pulmonary artery and its branches and peripheral vascular remodeling. It is a chronic complication of acute pulmonary embolism. The obstruction of pulmonary artery branches increases pulmonary vascular resistance (PVR) and this leads to the right ventricular overload and right-sided heart failure. The treatment of choice is surgical pulmonary endarterectomy (PEA), a procedure that is performed in deep hypothermic cardiac arrest. Patients with peripheral type of CTEPH, who are not indicated for operation and also patients with residual pulmonary hypertension after PEA can be indicated for specific vasodilatation therapy. In indicated cases the treatment may involve the balloon pulmonary angioplasty or lung transplantation. Despite the high effectivity of PEA, there is a number of patients, whose pulmonary arterial pressure remains high and this plays a key role in postoperative mortality and morbidity. Incidence of residual pulmonary hypertension is according to literature between 16 and 51%. This leads to a pursuit of finding possible tools to predict residual pulmonary hypertension after PEA. The aim of...
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Comparison of Methods of Left Appendage Exclusion During Surgical Ablation of Atrial Fibrillation
Kohut, Marián ; Kuntscher, Vilém (advisor) ; Skalický, Tomáš (referee) ; Rohn, Vilém (referee)
Comparison of methods of left atrial appendage exclusion during surgical ablation of atrial fibrilation Abstract Atrial fibrillation is the most common heart arrhytmia affecting a significant part of the population over 60 years of age and it is an eminent source of cardio-embolic events. Leading source of intra-cardial thrombi is the left atrium of the heart, specifically the left atrial appendage. Randomised studies show significant reduction of cerebral ictus by the use of Warfarin in patients with atrial fibrillation, however the use of anticoagulation has its restrictions, side effects and contraindications. There are several surgical techniques of excision or exclusion of the left atrial auricle. This dissertation thesis is focusing on the comparison of the two most common surgical techniques - resection of the left atrial appendage using a stapler and the exclusion of the left auricle using a clip applied from the pericardial side. At the same time, we've set an objective of confirming the electrical insulation of the left atrial appendage as a significant source of fibrillation impulses when using the clip for the left appendage exclusion. In a group of 30 patients with atrial fibrillation and who underwent the surgical atrial fibrillation ablation using a clip or stapler amputation during complex...
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Long Pentraxin 3 - a Putative Biomarker with Predictive Value to Identify the Adverse Inflammatory Response in Cardiac Surgical Patients?
Holubcová, Zdeňka ; Manďák, Jiří (advisor) ; Lonský, Vladimír (referee) ; Rohn, Vilém (referee)
(LONG PENTRAXIN 3 - A PUTATIVE BIOMARKER WITH PREDICTIVE VALUE TO IDENTIFY THE ADVERSE INFLAMMATORY RESPONSE IN CARDIAC SURGICAL PATIENTS?) INTRODUCTION. Cardiac surgery is well established for development of systemic inflammatory response. There are still no biomarkers with significant predictive value to identify patients at risk. AIM. The aim of this study was to compare the dynamics of pentraxin 3 (PTX3) and other inflammatory biomarkers (CRP, TLR2 and IL-8) after cardiac surgery with particular regards to different postoperative clinical manifestation of inflammatory response. Furthermore to evaluate the association between perioperative inflammatory biomarkers (PTX3, CRP, IL-8, IL-18, IL-18BP, TLR2, MMP7, MMP8, sFas a sFasL) and atrial fibrillation (AF) in cardiosurgical patients. METHODS. Forty-two patients undergoing open heart surgery with the use of cardiopulmonary bypass were included in the study and divided in 2 groups according to the extent of clinical manifestation of inflammatory response: Group A (n = 21) - patients with different severity of systemic inflammatory response syndrome (SIRS) and Group B (n = 21) - patients with uneventful postoperative period (no SIRS). The same group of 42 patient were divided in 3 groups according to occurrence of atrial fibrillation (AF): Group A...
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Development of vascular substitues for low flow peripheral vascular reconstructions
Mitáš, Petr ; Špaček, Miroslav (advisor) ; Štádler, Petr (referee) ; Rohn, Vilém (referee)
The development of vascular replacement for low flow rates is a topical issue. The model for developing the development of replacement properties, which are based on the idea of assuming the characteristics of the biological model - vena saphena and programming these properties into a model of constructed replacement is one of the possible directions of development. The presented replacement, which is the result of the work of the author's team, consists of three parts - a non-absorbable scaffold representing the media, and two absorbable collagen layers - pseudointima and pseudoadventice. Target parameters of the prosthesis were determined by test results of the basic physical testing method - uniaxial tensile test and inflation-extension test, as well as other procedures in human saphenous specimens. The key issue is the technology of producing the collagen layer of the prosthesis. However, other manufacturing processes can also have a significant impact on vascular prosthesis properties, such as collagen hardening, antithrombogenic treatment of the inner surface of the vascular replacement, and the use of a sterilization method. Furthermore, the author deals with the development of a new female component of the three- layer vascular prosthesis of the Czech carp, which is characterized by lower...
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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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Pathophysiological consequences of different cardiac support regimens in cardiorespiratory insufficiency
Lacko, Stanislav ; Kittnar, Otomar (advisor) ; Havránek, Štěpán (referee) ; Rohn, Vilém (referee)
Introduction: Veno-arterial extracorporeal membrane oxygenation (VA ECMO) is a rapidly applicable type of mechanical circulatory support that overcomes acute hemodynamic breakdowns, whether in acute or chronic heart failure or cardiac arrest. In recent years, the method has seen a very significant increase in use. VA ECMO can fully replace the function of the heart and lungs, delivering about 5 l / min of fully saturated blood. However, the method is burdened with a number of risks. Currently much-discussed issue is the effect of circulatory support on left ventricular residual function as VA ECMO increases its work and the risk of developing left ventricular distension and subsequent pulmonary edema. A detailed analysis of these pathophysiological mechanisms is a key objective of this work. Methods: The focus of the work is three series of experiments on a large biomodel (domestic pig). First, we developed a new model of acute hypoxic-ischemic heart failure by proximal occlusion of one of the main branches of the left coronary artery with a balloon catheter with a lumen for controlled perfusion of deoxygenated venous blood behind the balloon. Furthermore, we monitored the hemodynamic response and energy parameters in detail in the porcine biomodel of acute and chronic heart failure with a gradual...
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Fish collagen foam properties optimalization for medical and veterinary use.
Lukáč, Peter ; Grus, Tomáš (advisor) ; Rohn, Vilém (referee) ; Matia, Ivan (referee)
V průběhu projektu byly vyvinuty unikátní kolagenní pěny z kolagenu získaného z kůže sladkovodní ryby (kapr obecný, Cyprinus carpio). Pomocí síťování karbodiimidem byl překonán problém s nestabilitou kolagenní matrix z kolagenu získávaného z chladnokrevných živočichů při tělesné teplotě savců. Následně byly pěny impregnovány antibiotiky (gentamicin a vankomycin) a opětovně lyofilizovány, což je postup, který zajišťuje požadovanou koncentraci antibiotika bez rizika následného vymytí při dalších technologických krocích. Uvedený produkt je, na rozdíl od přípravků z nesíťovanéhokolagenu, stabilní i při sterilizaci gamma zářením. Finální sterilizovaný produkt byl testován in vivo na potkaním modelu infikované rány. Byla prokázána efektivita v léčbě potenciálně letální infekce Pseudomonas aeruginosa a kmene Stafylococcus aureus rezistentní k meticilinu (MRSA). Vzhledem k vysoké potřebě profylaxe a terapie infekcí pooperačních a jiných ran právě výše uvedenými polyrezistentními původci se jedná o slibný prostředek k budoucímu klinickému využití. Zkušenosti, které jsme získali v průběhu uvolnování ATB z kolagenních pěn budou v dalším vyvoji použity pro impregnaci zevní kolagenní vrstvy cévní protézy, čímž bychom mohli eliminovat jednu z největších nevýhod a rizik spojených s použitím umělých materiálu a tím je...
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Current possibilities of influence long-term patency of coronary artery bypass grafts
Skalský, Ivo ; Rohn, Vilém (advisor) ; Adamec, Miloš (referee) ; Němec, Petr (referee)
The main complication of aortocoronary reconstruction with vein grafts is restenosis in the course of time. The aim was to assess the effect of a periadventitial polyester system releasing sirolimus on intimal hyperplasia of autologous grafts. The controlled-release system comprises a polyester mesh coated with a sirolimus-eluting copolymer of L lactic acid and ε-caprolactone system designed to be wrapped around an autologous venous graft during its implantation. In vitro sirolimus release and its effects on smooth muscle and endothelial cells were assessed. In vitro, the copolymer-coated polyester mesh released sirolimus over a period of 6 weeks. Mesh-eluted sirolimus inhibited the growth of smooth muscle and endothelial cells in seven-day in vitro experiments. After seven days of sirolimus release from the mesh, smooth muscle and endothelial cell counts decreased by 29% and 75%, respectively, with the cells maintaining high viability. We implanted v. jugularis ext. into a. carotis communis in rabbits. The vein graft was either intact, or was wrapped with a pure polyester mesh, or with a sirolimus-releasing mesh. Three and six weeks after surgery, the veins were subjected to standard histological staining and the thicknesses of the tunica intima, the media and the intima-media complex were...
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Impact of Minimally Invasive Approach on Pulmonary Function in Patients Undergoing Aortic Valve Replacement
Gofus, Ján ; Pojar, Marek (advisor) ; Rohn, Vilém (referee) ; Šantavý, Petr (referee)
of the dissertation Impact of minimally invasive approach on pulmonary function in patients undergoing aortic valve replacement MUDr. Ján Gofus The most common minimally invasive approach to aortic valve replacement is upper hemisternotomy, which has been implemented at our department, as well. Preserving the lower half of thoracic cage could lead to lower postoperative drop of pulmonary function, apart from other benefits. Nevertheless, publications on this topic are insufficient and controversial. Our aim was to perform a prospective randomized trial comparing upper hemisternotomy with standard (median) sternotomy in terms of pulmonary function changes perioperatively. We also added a novel exercise tolerance test, one-minute sit-to-stand test, and a quality of life evaluation to the study. We included patients indicated for elective isolated aortic valve replacement with bioprosthesis who were older than 65 years, signed informed consent, and in which both surgical approaches were technically feasible. Exclusion criteria were re-do surgery and concomitant cardiac surgery. Patients were randomized to minimally invasive and standard group in 1:1 ratio. On the day of admission, on the 7th postoperative day and 3 months postoperatively, the patients underwent pulmonary function testing and one-minute...
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