Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Jan Sitar is active.

Publication


Featured researches published by Jan Sitar.


European Journal of Echocardiography | 2011

The role of exercise echocardiography in the diagnostics of heart failure with normal left ventricular ejection fraction

Jaroslav Meluzín; Jan Sitar; Jan Křístek; Robert Prosecký; Martin Pešl; Helena Podroužková; Vladimír Soška; Roman Panovský; Ladislav Dušek

AIMS Few data are available on the exercise-induced abnormalities of myocardial function in patients with exertional dyspnoea and normal left ventricular ejection fraction (LV EF). The main aims of this study were to determine the prevalence of isolated exercise-induced heart failure with normal ejection fraction (HFNEF) and to assess whether disturbances in LV or right ventricular longitudinal systolic function are associated with the diagnosis of HFNEF. METHODS AND RESULTS Eighty-four patients with exertional dyspnoea and normal LV EF and 14 healthy controls underwent spirometry, NT-proBNP plasma analysis, and exercise echocardiography. Doppler LV inflow and tissue mitral and tricuspid annular velocities were analysed at rest and immediately after the termination of exercise. Of the 30 patients with the evidence of HFNEF, 6 (20%) patients had only isolated exercise-induced HFNEF. When compared with the remaining patients, those with HFNEF had a significantly lower resting and exercise peak mitral annular systolic velocity (Sa) and the mitral annular velocity during atrial contraction, lower exercise peak mitral annular velocity at early diastole, and lower exercise peak systolic velocity of tricuspid annular motion. The multivariate logistic regression analysis including both parameters standardly defining HFNEF and the new Doppler variables potentially associated with the diagnosis of HFNEF revealed that NT-proBNP, LV mass index, left atrial volume index, and Sa significantly and independently predict the diagnosis of HFNEF. CONCLUSION A significant proportion of patients require exercise to diagnose HFNEF. Sa appears to be a significant independent predictor of HFNEF, which may increase the diagnostic value of models utilizing the variables recommended by the European Society of Cardiology guidelines.


Catheterization and Cardiovascular Interventions | 2014

Early outcomes of alcohol septal ablation for hypertrophic obstructive cardiomyopathy: a European multicenter and multinational study.

Josef Veselka; Thorsten Lawrenz; Christoph Stellbrink; David Zemánek; Marian Branny; Jaroslav Januška; Jan Sitar; Pawel Petkow Dimitrow; Jan Krejčí; Maciej Dabrowski; Stanislav Mizera; Thomas Bartel; Horst Kuhn

Background: This study was designed to evaluate the outcomes of alcohol septal ablation (ASA) under multicenter and multinational conditions. Methods: Data for 459 patients (age 57 ± 13 years) from nine European centers were prospectively collected and retrospectively analyzed. Results: ASA led to a significant reduction in outflow gradient (PG) and dyspnea [median of PG from 88 (58–123) mm Hg to 21 (11–41) mm Hg; median of NYHA class from 3 (2–3) to 1 (1–2); P < 0.01]. The incidence of 3‐month major adverse events (death, electrical cardioversion for tachyarrhythmias, resuscitation) and mortality was 2.8% and 0.7%, respectively. Permanent pacemakers for post‐ASA complete heart block were implanted in 43 patients (9%). Multivariate analysis identified higher amount of alcohol (however, in generally low‐dose procedures), higher baseline left ventricular ejection fraction and higher age as independent predictors of PG decrease ≥50%. Conclusions: The results of the first European multicenter and multinational study demonstrate that real‐world early outcomes of ASA patients are better than was reported in observations from the first decade after ASA introduction.


The Cardiology | 2009

Intracoronary Delivery of Bone Marrow Cells to the Acutely Infarcted Myocardium

Jaroslav Meluzín; Michal Vlašín; Ladislav Groch; Jiří Mayer; Leoš Křen; Petr Raušer; Boris Tichý; Ivan Horňáček; Jan Sitar; Stanislav Palša; Martin Klabusay; Zdeněk Kořístek; Michael Doubek; Šárka Pospíšilová; L. Lexmaulová; Ladislav Dušek

Objectives: Intracoronary cell transplantation during catheter balloon inflations may be associated with adverse events. We studied the effectiveness of an alternative transplantation technique – intracoronary cell infusion. Methods: Fourteen pigs, which had survived acute myocardial infarction, were randomized into 2 treatment groups and 2 controls. Three days after infarction, 12 pigs underwent allogeneic intracoronary mononuclear bone marrow cell transplantation using either the standard technique (short-term cell injections during repeat balloon inflations, technique A, n = 6) or continuous intracoronary cell infusion without balloon inflations (technique B, n = 6). Implanted cells were stained with fluorescent dye. After transplantation, the pigs were euthanized and myocardial samples were analyzed by fluorescent microscopy. Results: The mean numbers of fluorescently labeled bone marrow cells in the infarction border zone, in the infarction mid-area and in the center of myocardial infarction were 84, 72 and 55 using technique A, and 29, 57 and 46 using technique B, respectively. The mean cell retention in the infarction border zone of 84 cells for technique A and 29 cells for technique B differed significantly (p = 0.034, two-tailed t test). Conclusion: The continuous intracoronary cell infusion technique is a less efficient cell delivery technique as compared with the standard technique using repeat intracoronary balloon inflations.


Disease Markers | 2012

Matrix metalloproteinase 13 genotype in rs640198 polymorphism is associated with severe coronary artery disease.

Anna Vašků; Jaroslav Meluzín; Jan Blahák; Vladimír Kincl; Monika Pávková Goldbergová; Jan Sitar; Filip Zlámal; Julie Bienertová-Vašků; Jiří Vítovec

Atherosclerosis as a main etiopathogenetic source for coronary artery disease (CAD) development is intimately related to dynamic changes in the extracellular matrix (ECM). Elevated levels of MMP-13 have been observed in human atherosclerotic plaques which could also involve variability in MMP-13 gene. The aim of the study was to associate rs640198 polymorphism with CAD and/or with its severity. The study comprised 1071 consecutive patients with suspected or known coronary artery disease (CAD), confirmed by coronary angiography. Genotyping for the rs640198 polymorphism in MMP-13 gene was performed using Taqman® assay. The TT and TG genotypes of rs640198 polymorphism in MMP-13 gene confer the significantly increased risk of triple vessel disease compared to patients without atherosclerotic lesions in coronary arteries (odds ratio = 1.64, Pcorr = 0.05). Furthermore, an increased risk of having 5 and more stenoses (odds ratio = 1.90, Pcorr = 0.004) was observed in TT and TG carriers (sensitivity of 0.613 and a specificity of 0.544; power of the test is 0.87). The T allele of MMP-13 intron polymorphism rs640198 is associated with the severity of coronary artery disease, represented by the number of affected arteries as well as by the number of stenoses confirmed by coronarography.


Clinical Cardiology | 2009

The Effect of Short-term Isometric Muscle Contraction and the Valsalva Maneuver on Systemic and Pulmonary Hemodynamics in Patients with Severe Heart Failure

Miroslav Souček; Petr Frana; Tomáš Kára; Jan Sitar; Josef Halámek; Pavel Jurák; Ivan Rihacek; Lenka Špinarová; Ivo Oral

Chronic heart failure is characterized by high mortality, frequent hospitalization, and reduced quality of life. Patients with severe heart failure are often in very poor physical condition, they are unable to take part in the usual exercise programs, and therefore need an individual approach.


Biomedical Papers-olomouc | 2016

Longitudinal, circumferential and radial systolic left ventricular function in patients with heart failure and preserved ejection fraction.

Zdenka Gregorova; Jaroslav Meluzín; Radka Stepanova; Jan Sitar; Helena Podrouzkova; Lenka Špinarová

INTRODUCTION Heart failure with preserved left ventricular ejection fraction (HFPEF) is an epidemiologically serious disease. Noninvasive diagnosis of HFPEF remains challenging. The current diagnosis is based on evidence of diastolic dysfunction, albeit systolic dysfunction is also present but not included in the diagnostic algorithm. The aim of this study was to analyze the longitudinal (long), circumferential (circ) and radial (rad) component of systolic left ventricular (LV) function in patients with exertional dyspnea of unexplained etiology and normal left ventricular ejection fraction (LVEF). METHODS One hundred and twenty-two patients with exertional dyspnea of unexplained etiology and normal LVEF and 21 healthy controls, underwent echocardiography examination at rest and at the end of symptom-limited exercise. We analysed the longitudinal, circumferential and radial deformation of myocardium using two dimensional speckle tracking echocardiography in all subjects. RESULTS Patients with exertional dyspnea and preserved LVEF were divided into group A1 (46 patients meeting the criteria for the diagnosis HFPEF) and group A2 (76 patients without HFPEF). Group A1 had significantly worse longitudinal and circumferential systolic LV function than group A2. Subjects in group A1 compared to group A2 showed significantly different strain rates during atrial contraction (SR A), circ and ratio of peak early trans-mitral flow velocity (E) and strain rate E wave (E / SR E) circ. Multivariate logistic regression analysis showed that the SR parameter A circ is an independent predictor of HFPEF (odds ratio 0.550, 95% confidence interval: 0.370 - 0.817, P value 0.003). CONCLUSION Longitudinal and circumferential LV deformation was significantly more impaired in patients with HFPEF than in patients with exertional dyspnea without HFPEF. In patients with exertional dyspnea and normal LVEF, the value of SRA circ appears to be a significant and independent predictor of HFPEF. This parameter may, in the future complement the diagnostic algorithm for HFPEF.


The Journal of Critical Care Medicine | 2015

Ventricular Septal Rupture – A Critical Condition as a Complication of Acute Myocardial Infarction

Martin Novák; Ota Hlinomaz; Ladislav Groch; Michal Rezek; Jiri Semenka; Jiri Sikora; Jan Sitar

Abstract Ventricular septal rupture is a potentially fatal complication of acute myocardial infarction. The key to management of this critical condition is an aggressive approach to haemodynamic stabilization and surgical closure of the rupture. Where there is a small rupture and the patient is in a haemodynamically stable condition, surgery can be delayed with the prospect of achieving better perioperative results. However, in unstable critically ill patients either immediate surgery or extracorporeal membranous oxygenation support and delayed surgery is indicated. In some patients, trans-catheter closure may be considered as an alternative to surgery.


Bratislava Medical Journal-bratislavske Lekarske Listy | 2017

Conservative versus invasive treatment in hypertrophic obstructive cardiomyopathy: an echocardiography study

Tomáš Honek; Jan Krejčí; Jan Máchal; Ladislav Groch; Jan Sitar; Jaroslav Meluzín; Lenka Špinarová

AIM AND METHODS The aim of our study was to compare the development of echocardiographic parameters and functional status of patients with hypertrophic obstructive cardiomyopathy (HOCM) treated conservatively (n = 41) or by alcohol septal ablation (ASA; n = 39). RESULTS Left ventricular outflow tract gradient (LVOTG) decreased in the first year by 53.7±36.4 mmHg in ASA group versus 5.5±47.1 mmHg in conservatively treated group (p<0.001), in the third year by 53.1±41.4 mmHg versus 23.9±42.7 mmHg (p = NS) and in the fifth year, the reduction of LVOTG was 52.1±44.5 mmHg in ASA group and 3.0±63.2 mmHg in conservatively treated group (p<0.05).Change in NYHA class in the first year was -1.1±0.4 versus 0.1±0.5, in the third year -1.0±0.6 versus 0.1±0.4 and in the fifth year -0.8±0.5 versus 0.1±0.4 (all p<0.001). CONCLUSION Our results showed for the first time that decline of LVOTG after ASA creates a favorable left ventricle remodeling and leads to significant improvement of functional status of HOCM patients in comparison with conservative treatment (Tab. 3, Fig. 2, Ref. 42).


Journal of Cardiovascular Emergencies | 2016

How To Treat Spontaneous Coronary Artery Dissection

Jan Sitar; Ladislav Groch; Ota Hlinomaz; Michal Rezek; Jiří Seménka

Abstract Spontaneous coronary artery dissection (SCAD) is a rare disease, occurring most often in young women, around 40 years of age. Usually there is the presence of several predisposing factors. Diagnosis is made using coronary angiography, optical coherence tomography (OCT) or autopsy. Optical coherence tomography allows a precise diagnosis to be made, identifying as it can, a coronary artery intramural haematoma prior to the occurrence of a dissecting lesion. The case of a 52-year-old woman with SCAD of unknown etiology is reported.


Journal of Cardiovascular Emergencies | 2015

New Imaging Methods of Coronary Arteries in Acute Coronary Syndromes

Ota Hlinomaz; Ladislav Groch; Jan Sitar; Michal Rezek; Jiří Seménka; Martin Novák; Nikolay Penkov

Abstract Coronary angiography is still the most widely used method for the assessment of lumen of coronary arteries and for diagnosis and treatment of coronary artery disease. New imaging modalities of coronary arteries play an increasing role in interventional cardiology. Intravascular ultrasound (IVUS) is the oldest technology, however due to its high tissue penetration remains very important for imaging of left main coronary artery and saphenous vein grafts. IVUS was used in many clinical trials and clinical experience with it is huge. Optical coherence tomography (OCT) is a new, very fast developing method. It has ten times higher axial resolution than IVUS. It gives us the opportunity to assess the inner structures of coronary artery wall, to evaluate the characteristics of atherosclerotic plaques, quality of stent implantation and its healing. It helps us to find the culprit lesion of acute coronary syndrome in some cases, to diagnose the cause of stent thrombosis, and to evaluate stent apposition which has a direct relation to prognosis. We use it to perform complex percutaneous coronary interventions and after heart transplantation to diagnose the vascular graft disease. We strongly believe that OCT is important for the assessment of plaque instability and patient´s prognosis. Near infrared spectroscopy combined with IVUS can distinguish fibrous from lipid core plaques. Lipid core burden index is in relation to a risk of periprocedural myocardial infarction and to prognosis. It is the only method which can sufficiently detect the amount of lipids in coronary wall.

Collaboration


Dive into the Jan Sitar's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge