WorldCat Identities

Tyšler, Milan

Overview
Works: 7 works in 8 publications in 1 language and 20 library holdings
Genres: Conference papers and proceedings 
Roles: Editor, Other
Classifications: QA465, 616.1
Publication Timeline
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Most widely held works by Milan Tyšler
2017 11th International Conference on Measurement proceedings : Congress Center of the Slovak Academy of Sciences, Smolenice Castle, Slovakia, May 29-31, 2017 by International Conference on Measurement( )

1 edition published in 2017 in English and held by 12 WorldCat member libraries worldwide

The roles of mid-myocardial and epicardial cells in T-wave alternans development: a simulation study by D Janusek( )

2 editions published in 2018 in English and held by 3 WorldCat member libraries worldwide

Background: The occurrence of T-wave alternans in electrocardiographic signals was recently linked to susceptibility to ventricular arrhythmias and sudden cardiac death. Thus, by detecting and comprehending the origins of T-wave alternans, it might be possible to prevent such events. Results: Here, we simulated T-wave alternans in a computer-generated human heart model by modulating the action potential duration and amplitude during the first part of the repolarization phase. We hypothesized that changes in the intracardiac alternans patterns of action potential properties would differentially influence T-wave alternans measurements at the body surface. Specifically, changes were simulated globally in the whole left and right ventricles to simulate concordant T-wave alternans, and locally in selected regions to simulate discordant and regional discordant, hereinafter referred to as “regional”, T-wave alternans. Body surface potential maps and 12-lead electrocardiographic signals were then computed. In depth discrimination, the influence of epicardial layers on T-wave alternans development was significantly higher than that of mid-myocardial cells. Meanwhile, spatial discrimination revealed that discordant and regional action potential property changes had a higher influence on T-wave alternans amplitude than concordant changes. Notably, varying T-wave alternans sources yielded distinct body surface potential map patterns for T-wave alternans amplitude, which can be used for location of regions within hearts exhibiting impaired repolarization. The highest ability for T-wave alternans detection was achieved in lead V1. Ultimately, we proposed new parameters Vector Magnitude Alternans and Vector Angle Alternans , with higher ability for T-wave alternans detection when using multi-lead electrocardiographic signals processing than for single leads. Finally, QT alternans was found to be associated with the process of T-wave alternans generation. Conclusions: The distributions of the body surface T-wave alternans amplitude have been shown to have unique patterns depending on the type of alternans (concordant, discordant or regional) and the location of the disturbance in the heart. The influence of epicardial cells on T-wave alternans development is significantly higher than that of mid-myocardial cells, among which the sub-endocardial layer exerted the highest influence. QT interval alternans is identified as a phenomenon that correlate with T-wave alternans
Noninvasive identification of two lesions with local repolarization changes using two dipoles in inverse solution simulation study( )

1 edition published in 2015 in English and held by 1 WorldCat member library worldwide

Abstract: Background: The method for inverse localization and identification of two distinct simultaneous lesions with changed repolarization in the ventricular myocardium (two-vessel disease) is proposed and its robustness to errors in input data is tested in this simulation study. Method: The inverse solution was obtained from the difference between STT integral body surface potential map computed with repolarization changes and the STT integral map from normal activation. In a numerical model of ventricles 48 cases of two simultaneous lesions and 48 cases of a single lesion were modeled. The effect of the lesions was taken to be represented by two dipoles. The input data were disturbed by three types of added noise. Twenty three characteristics of every obtained inverse solution were defined and four of them were used as the features in discriminant analysis task distinguishing the correct inverse solutions identifying two lesions. Results: The mean localization error for identified two lesions was 1.1±0.7 cm. The sensitivity and specificity of quadratic discriminant analysis with cross-validation and feature selection was higher than 90%. Conclusions: The combination of the inverse solution with two dipoles and discriminant analysis allows the identification of two simultaneous lesions without a priori information about the number of lesions. Highlights: We modeled one or two lesions with repolarization changes in heart ventricle. We computed difference integral body surface potential maps on the torso surface. We suggested the inverse solution for identification of two lesions by two dipoles. Characteristics of solutions were specified for classification of correct solutions. For suggested method no apriori information about the number of lesions is needed
Measurement 2001 : proceedings ; 3rd International Conference on Measurement, Congress Centre of SAS, Smolenice Castle, Slovak Republic, May 14-17, 2001 by International Conference on Measurement( Book )

1 edition published in 2001 in English and held by 1 WorldCat member library worldwide

Measurement 2003 : 4th International Conference on Measurement, Congress Centre of SAS, Smolenice Castle, Slovak Republic, June 15-19, 2003 ; proceedings by International Conference on Measurement( Book )

1 edition published in 2003 in English and held by 1 WorldCat member library worldwide

Measurement 2005 : 5th International Conference on Measurement, Congress Centre of SAS, Smolenice Castle, Slovak Republic, May 15-19, 2005 : proceedings by International Conference on Measurement( Book )

1 edition published in 2005 in English and held by 1 WorldCat member library worldwide

Measurement 2009 : 7th International Conference on Measurement, proceedings, Congress Centre of SAS, Smolenice Castle, Slovakia, May 20-23, 2009 by International Conference on Measurement( Book )

1 edition published in 2009 in English and held by 1 WorldCat member library worldwide

 
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Alternative Names
Tyšler, M.

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