Anton Mateasik

International Laser Centre, Presburg, Bratislavský, Slovakia

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Publications (55)71.6 Total impact

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    ABSTRACT: Material and methods: The model defines the geometry of cardiac ventricles analytically as parts of ellipsoids; the left ventricular wall is represented by five layers. The impulse propagation velocity was decreased by 50% in one and two midwall layers, respectively, in the whole left ventricle and in LV anterior region. The effects of slowed conduction velocity on the QRS complex of the 12-lead electrocardiogram are presented as 12-lead electrocardiograms and corresponding values of ECG criteria for left ventricular hypertrophy (ECG-LVH criteria): Gubner criterion, Sokolow-Lyon index (SLI) and Cornell voltage. Results: All simulated situations led to increased R wave amplitude in the lead I and of S wave in the lead III, showing a leftward shift of the electrical axis and increased values of ECG-LVH criteria based on limb leads alone or in combination with precordial leads (Gubner criterion, Cornell voltage). The slowed conduction velocity in the whole LV influenced the QRS complex voltage in precordial leads, having an impact on the SLI and Cornell voltage. The changes were pronounced if two layers were involved. Conclusion: Using computer modeling we showed that the midwall slowing in conduction velocity modified the QRS complex morphology. The QRS complex changes were consistent with ECG-LVH criteria, i.e. QRS patterns usually interpreted as the effect of left ventricular hypertrophy (the increased left ventricular mass).
    No preview · Article · Dec 2015 · Journal of electrocardiology
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    ABSTRACT: Fabricated micro- and nano-structured surfaces were evaluated for use with living cells. Metabolic state was tested by means of endogenous flavin fluorescence of living peripheral blood mononuclear cells (PBMC) positioned on a coverslip, non-covered, or covered with micro- or nano-structured surfaces (OrmoComp polymer structures produced by 2-photon photopolymerisation, or Zinc Oxide (ZnO) layer fabricated by pulsed laser deposition). Confocal microscopy and Fluorescence Lifetime Imaging Microscopy (FLIM) were employed to gather flavin fluorescence lifetime images of living PBMC on structured surfaces. Gathered data are the first step towards monitoring of the live cell interaction with different micro/nano-structured surfaces and thus evaluate their potential applicability in the biomedical field.
    No preview · Article · Jan 2015
  • Ljuba Bacharova · Vavrinec Szathmary · Anton Mateasik

    No preview · Article · Dec 2014 · Journal of Electrocardiology
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    ABSTRACT: Despite the low sensitivity of the electrocardiogram (ECG) in detecting left ventricular hypertrophy (LVH), ECG-LVH is known to be a strong predictor of cardiovascular risk. Understanding reasons for the discrepancies in detection of LVH by ECG versus imaging could help improve the diagnostic ability of ECG. We examined factors associated with false-positive and false-negative ECG-LVH, using cardiac magnetic resonance imaging (MRI) as the gold standard. We also compared the prognostic significance of ECG-LVH and MRI-LVH as predictors of cardiovascular events. This analysis included 4,748 participants (mean age 61.9 years, 53.5% females, 61.7% nonwhites). Logistic regression with stepwise selection was used to identify factors associated with false-positive (n = 208) and false-negative (n = 387), compared with true-positive (n = 208) and true-negative (n = 4,041) ECG-LVH, respectively. A false-negative ECG-LVH status was associated with increased odds of Hispanic race/ethnicity, current smoking, hypertension, increased systolic blood pressure, prolongation of QRS duration, and higher body mass index and with lower odds of increased ejection fraction (model-generalized R(2) = 0.20). A false-positive ECG-LVH status was associated with lower odds of black race, Hispanic race/ethnicity, minor ST-T abnormalities, increased systolic blood pressure, and presence of any major electrocardiographic abnormalities (model-generalized R(2) = 0.29). Both ECG-LVH and MRI-LVH were associated with an increased risk of cardiovascular disease events (hazard ratio 1.51, 95% confidence interval 1.03 to 2.20 and hazard ratio 1.81, 95% confidence interval 1.33 to 2.46, respectively). In conclusion, discrepancy in LVH detection by ECG and MRI can be relatively improved by considering certain participant characteristics. Discrepancy in diagnostic performance, yet agreement on predictive ability, suggests that LVH by ECG and LVH by imaging are likely to be two distinct but somehow related phenotypes. Copyright © 2014 Elsevier Inc. All rights reserved.
    No preview · Article · Nov 2014 · The American Journal of Cardiology
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    ABSTRACT: Change in metabolic pathways is an important indicator of modifications in physiological, pathological and/or differentiation state of the cell. Its non-invasive investigation can significantly improve medical practice, namely the determination of the suspected tissue during surgery, including fast biopsy used for pre-operative tissue diagnostics, and/or resection guidance during surgical operations. Early detection of these changes is a prerequisite of fast and precise diagnostics directly in living cells and tissues and is thus crucial for the patient's survival and/or his/hers better quality of life. In this contribution, we review time-resolved fluorescence measurements of endogenous NAD(P)H in cells and tissues aimed at separation of specific metabolic pathways (glycolysis vs. oxidative phosphorylation – OXPHOS). Other complex situations, including the presence of oxidative stress, are also discussed. Current state of knowledge on non-invasive diagnostics of pathophysiological state in living cells and tissues, based on time-resolved autofluorescence, is presented.
    No preview · Article · Aug 2014
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    ABSTRACT: Background Acute myocardial infarction creates regions of altered electrical properties of myocardium resulting in typical QRS patterns (pathological Q waves) and ST segment deviations observed in leads related to the MI location. The aim of this study was to present a graphical method for imaging the changes in the sequence of depolarization and the ST segment deviations in myocardial infarction using the Dipolar ElectroCARdioTOpography (DECARTO) method. Material and Methods Simulated ECG data corresponding to intramural, electrically inactive areas encircled by transmural areas with slowed impulse propagation velocity in anteroseptal and inferior locations were used for imaging the altered sequence of depolarization and the ST vector. The ECGs were transformed to areas projected on the image surface so as to image the process of ventricular depolarization based on the orientation and magnitude of the instantaneous QRS vectors, and the estimated “myocardium at risk” based on the ST segment deviation. Results The images are presented as Mercator projections with the texture of anatomical segments of the heart and the corresponding coronary artery distribution. The changes in depolarization sequence were visible as dislocations of activated areas circumventing the affected areas, while the “myocardium at risk” estimated from the ST segment deviation pointed to the affected area. Conclusion The presented method of imaging ECG allows visualizing changes in sequence of depolarization as well as the ST segment deviations in myocardial infarction and they can be visually compared with non-ECG imaging methods.
    No preview · Article · Jul 2014 · Journal of Electrocardiology
  • Alzbeta Chorvatova · Anton Mateasik · Dusan Chorvat
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    ABSTRACT: We report a novel analytical approach to identify individual components of a cell's endogenous fluorescence, recorded by spectrally-resolved time-correlated single photon counting (TCSPC). Time-resolved area-normalized emission spectroscopy (TRANES) and principal component analysis (PCA) were applied to estimate the number of spectral components after metabolic modulation of cardiac cells following excitation with a 375 nm picosecond laser. Linear unmixing of TCSPC data spectrally decomposed individual components in living cells, while using characteristics of endogenously fluorescing molecules in solvents as a reference spectral database. Our data demonstrate the presence of three individual components, corresponding to the nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) in organic and inorganic solvents and to the residual flavoprotein fluorescence. The presented analytical approach offers a new alternative for the spectral separation of multi-wavelength fluorescence lifetime spectroscopy data to the conventional analysis, and opens a new possibility for the use of pattern recognition for fast resolution of components in 2D fluorescence lifetime microscopy images.
    No preview · Article · Dec 2013 · Laser Physics Letters
  • Ljuba Bacharova · Anton Mateasik · Vavrinec Szathmary

    No preview · Article · Nov 2013 · Journal of electrocardiology
  • Ljuba Bacharova · Vavrinec Szathmary · Anton Mateasik
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    ABSTRACT: Reduction or interruption of the blood supply to myocardium due to occlusion of coronary artery and consequent ischemia leads to changes of electrogenesis: changes in morphology and duration of action potentials and slowing of conduction velocity in the affected area. In this study we simulated the effects of localized changes in depolarization sequence on the QRS and ST segment patterns, using computer modeling. The model defines the geometry of cardiac ventricles analytically as parts of ellipsoids and allows changing the velocity of impulse propagation in the myocardium. An intramural electrically inactive area encircled by a transmural area with slowed impulse propagation velocity was introduced in anteroseptal and inferior locations. The effects on the QRS complex and the ST segment of the 12-lead electrocardiogram are presented. The intramural electrically inactive area caused QRS changes typical for corresponding locations of a myocardial infarction observed in patients, which were further considerably modified by slowed impulse propagation velocity in the surrounding area. Additionally, areas of slowed impulse propagation velocity led to ST segment deviations in the "reciprocal" leads, shifting the ST segment towards the affected areas. Using computer modeling we showed that the localized alteration of impulse propagation not only modified the QRS complex, but produced also changes in the ST segment consistent with changes which are usually interpreted as the effect of "injury current".
    No preview · Article · Sep 2013 · Journal of electrocardiology
  • L. Bacharova · A. Mateasik · V. Szathmary

    No preview · Article · Jul 2013 · Journal of Electrocardiology
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    ABSTRACT: Lipid peroxidation is a major biochemical consequence of the oxidative deterioration of polyunsaturated lipids in cell membranes and causes damage to membrane integrity and loss of protein function. 4-hydroxy-2-nonenal (HNE), one of the most reactive products of n-6 polyunsaturated fatty acid peroxidation of membrane phospholipids, has been shown to be capable of affecting both nicotinamide adenine dinucleotide (phosphate) reduced [NAD(P)H] as well as NADH production. However, the understanding of its effects in living cardiac cells is still lacking. Our goal was to therefore investigate HNE effects on NAD(P)H noninvasively in living cardiomyocytes. Spectrally resolved lifetime detection of endogenous fluorescence, an innovative noninvasive technique, was employed. Individual fluorescence components were resolved by spectral linear unmixing approach. Gathered results revealed that HNE reduced the amplitude of both resolved NAD(P)H components in a concentration-dependent manner. In addition, HNE increased flavoprotein fluorescence and responsiveness of the NAD(P)H component ratio to glutathione reductase (GR) inhibitor. HNE also increased the percentage of oxidized nucleotides and decreased maximal NADH production. Presented data indicate that HNE provoked an important cell oxidation by acting on NAD(P)H regulating systems in cardiomyocytes. Understanding the precise role of oxidative processes and their products in living cells is crucial for finding new noninvasive tools for biomedical diagnostics of pathophysiological states.
    No preview · Article · Jun 2013 · Journal of Biomedical Optics
  • A. Mateasik · D. Chorvat · A. Chorvatova
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    ABSTRACT: Spectral analysis of the autofluorescence images of isolated cardiac cells was performed to evaluate and to classify the metabolic state of the cells in respect to the responses to metabolic modulators. The classification was done using machine learning approach based on support vector machine with the set of the automatically calculated features from recorded spectral profile of spectral autofluorescence images. This classification method was compared with the classical approach where the individual spectral components contributing to cell autofluorescence were estimated by spectral analysis, namely by blind source separation using non-negative matrix factorization. Comparison of both methods showed that machine learning can effectively classify the spectrally resolved autofluorescence images without the need of detailed knowledge about the sources of autofluorescence and their spectral properties.
    No preview · Article · Feb 2013 · Proceedings of SPIE - The International Society for Optical Engineering
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    ABSTRACT: The genus Gluconobacter is frequently used for biotechnological and/or nanotechnological applications. We studied endogenous fluorescence of nicotinamide adenine dinucleotide (phosphate) (NAD(P)H), indicator of the oxidative metabolic state in mammalian cells, in Gluconobacter oxydans (G. oxydans). Time-resolved measurements (excitation by 375nm pulsed diode laser) were employed to record the bacterial fluorescence intensity, as well as its modifications by metabolic modulation. Results were gathered on fresh bacteria, on de-frozen ones, as well as on bacteria encapsulated in alginate beads. NAD(P)H fluorescence increased linearly with the concentration of bacteria. Freezing, which has little effect on the viability of bacteria or the concentration-dependent fluorescence rise, affected the temperature-dependence of NAD(P)H fluorescence. Sodium cyanide (10 mM) provoked significant rise in the NAD(P)H fluorescence, while dinitrophenol (200 μM) induced its decrease, confirming the bacterial NAD(P)H fluorescence sensitivity to modulators of electron transport chain. Gathered results demonstrate that endogenous NAD(P)H fluorescence can be successfully recorded in the bacterial strain G. oxydans using time-resolved measurements.
    No preview · Article · Jan 2013 · Proceedings of SPIE - The International Society for Optical Engineering
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    ABSTRACT: Time-resolved spectrometry of endogenous nicotinamide dinucleotide phosphate [NAD(P)H] fluorescence is a useful method to evaluate metabolic oxidative state in living cells. Ouabain is a well-known pharmaceutical drug used in the treatment of cardiovascular disease, the effects of which on myocardial metabolism were recently demonstrated. Mechanisms implicated in these actions are still poorly understood. We investigate the effect of ouabain on the metabolic oxidative state of living cardiac cells identified by time-resolved fluorescence spectroscopy of mitochondrial NAD(P)H. Spectral unmixing is used to resolve individual NAD(P)H fluorescence components. Ouabain decreased the integral intensity of NAD(P)H fluorescence, leading to a reduced component amplitudes ratio corresponding to a change in metabolic state. We also noted that lactate/pyruvate, affecting the cytosolic NADH gradient, increased the effect of ouabain on the component amplitudes ratio. Cell oxidation levels, evaluated as the percentage of oxidized NAD(P)H, decreased exponentially with rising concentrations of the cardiac glycoside. Ouabain also stimulated the mitochondrial NADH production. Our study sheds a new light on the role that ouabain plays in the regulation of metabolic state, and presents perspective on a noninvasive, pharmaceutical approach for testing the effect of drugs on the mitochondrial metabolism by means of time-resolved fluorescence spectroscopy in living cells.
    No preview · Article · Oct 2012 · Journal of Biomedical Optics
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    ABSTRACT: An increased QRS voltage is considered to be specific for the electrocardiogram (ECG) diagnosis of left ventricular hypertrophy (LVH). However, the QRS-complex patterns in patients with LVH cover a broader spectrum: increased QRS voltage, prolonged QRS duration, left axis deviation, and left anterior fascicular block- and left bundle branch block-like patterns, as well as pseudo-normal QRS patterns. The classical interpretation of the QRS patterns in LVH relates these changes to increased left ventricular mass (LVM) per se, while tending to neglect the modified active and passive electrical properties of the myocardium. However, it has been well documented that both active and passive electrical properties in LVH are altered. Using computer simulations, we have shown that an increased LVM is not the only determinant of QRS complex changes in LVH, as these changes could also be produced without changing the left ventricular mass, implying that these QRS patterns can be present in patients before their LVM exceeds the arbitrary upper normal limits. Our results link the experimental evidence on electrical remodeling with clinical interpretation of ECG changes in patients with LVH and stress the necessity of a complex interpretation of the QRS patterns considering both spatial and nonspatial determinants in terms of the spatial angle theory. We assume that hypertrophic electrical remodeling in combination with changes in left ventricular size and shape explains the variety of ECG patterns as well as the discrepancies between ECG and left ventricular mass.
    No preview · Article · Sep 2012 · Journal of electrocardiology
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    ABSTRACT: Cardiac cells are highly structured with a non-uniform morphology. Although precise estimation of their volume is essential for correct evaluation of hypertrophic changes of the heart, simple and unified techniques that allow determination of the single cardiomyocyte volume with sufficient precision are still limited. Here, we describe a novel approach to assess the cell volume from confocal microscopy 3D images of living cardiac myocytes. We propose a fast procedure based on segementation using active deformable contours. This technique is independent on laser gain and/or pinhole settings and it is also applicable on images of cells stained with low fluorescence markers. Presented approach is a promising new tool to investigate changes in the cell volume during normal, as well as pathological growth, as we demonstrate in the case of cell enlargement during hypertension in rats.
    Full-text · Article · May 2012 · Proceedings of SPIE - The International Society for Optical Engineering
  • P Mlkvý · I Cavarga · A Mateásik
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    ABSTRACT: Endoscopic mucosal resection and piece meal polypectomy are methods of choice in broad based unifocal rectosigmoideal lesions. Thermal ablative modalities are indicated for flat adenomas, lateral spreading tumors and as an adjunct therapeutic modality for incomplete polypectomy. Photodynamic therapy using ALA photosensitiser is effective in the treatment of multifocal lesions either alone or in a combination with thermal ablative techniques. At present "tailored suite" combination of these techniques for each patient according the character of the lesion is considered to be the most effective treatment for rectosigmoideal praecancerous lesions and early cancer.
    No preview · Article · Dec 2011 · Vnitr̆ní lékar̆ství
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    ABSTRACT: The electrocardiographic (ECG) diagnosis of left ventricular hypertrophy (LVH) is based on the assumption that QRS voltage increases with left ventricular mass. However, most of patients with echocardiographically detected LVH do not have increased QRS voltage. Reduced intercellular coupling has been observed in LVH patients and animal models. The purpose of this study was to show that this uncoupling can explain relatively low QRS voltage in LVH patients. Electrocardiograms and vectorcardiograms (VCG) were simulated with a realistic large-scale computer model of the human heart and torso that reliably represented the effects of reduced coupling on both propagation and ECG voltage. Uncoupling reduced QRS voltage in all leads except aVL, reflecting a decrease in vector amplitude as well as a leftward axis deviation that suggested left anterior fascicular block. Low QRS voltage does not necessarily contradict a diagnosis of LVH but may be an indication for electrical uncoupling. The diagnostic value of this "relative voltage deficit" needs to be demonstrated in clinical studies.
    Full-text · Article · Jul 2011 · Journal of electrocardiology
  • Ljuba Bacharova · Vavrinec Szathmary · Anton Mateasik
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    ABSTRACT: By definition, the electrocardiographic (ECG) patterns of left bundle-branch block (LBBB) represent distinctive changes in duration and shape of the QRS complex caused by intraventricular conduction delay in the left ventricle (LV) due to structural abnormalities in the His-Purkinje conduction system and/or ventricular myocardium. However, impaired conduction in the working myocardium is not taken into consideration in the practical ECG diagnosis. Because the degree of LV myocardium impairment could be of importance for clinical evaluation of patients, we studied the effects of blocked and of delayed onsets of activation in the LV to simulate complete and incomplete LBBBs and slowed conduction in the LV myocardium by applying an analytical computer model. We demonstrated that typical LBBB patterns were caused both by block or delay in the onset of the LV activation, as well as by impaired conduction in the myocardium itself while maintaining the location and onset of the LV activation. The most important difference was the absence of initial anteriorly oriented electrical forces in cases of the simulated complete LBBB and of incomplete LBBB if the onset of LV activation was delayed (≥ 6 milliseconds). Under the conditions defined in this model that did not consider myocardial infarction, the presence of initial anteriorly oriented electrical forces was indicative of preserved conduction in the left bundle and of impaired conduction in LV working myocardium. CONCLUSION: The elucidation of the participation of working myocardium impairment in the intraventricular conduction delay in the LV could be of vital significance for the clinical management of patients with LBBB patterns, for example, indicated for resynchronization therapy.
    No preview · Article · Jun 2011 · Journal of electrocardiology
  • P. Mlkvy · I. Cavarga · A. Mateasik · D. Poruban · D. Chorvat

    No preview · Article · Jun 2011 · Photodiagnosis and Photodynamic Therapy

Publication Stats

347 Citations
71.60 Total Impact Points


  • 2001-2015
    • International Laser Centre
      Presburg, Bratislavský, Slovakia
  • 2011
    • St. Elizabeth Cancer Institute Hospital - Onkologický ústav sv. Alžbety, s.r.o
  • 2010
    • Slovak Academy of Sciences
      • Institute of Normal and Pathological Physiology
      Presburg, Bratislavský, Slovakia
  • 2004
    • Comenius University in Bratislava
      Presburg, Bratislavský, Slovakia