Dariusz Janusek

Learn More
BACKGROUND The effective screening of myocardial infarction (MI) patients threatened by ventricular tachycardia (VT) is an important issue in clinical practice, especially in the process of implantable cardioverter-defibrillator (ICD) therapy recommendation. This study proposes new parameters describing depolarization and repolarization inhomogeneity in(More)
The aim of the study was a selection of best ECG leads to get the significant T-wave alternans signal (TWA). The group of 16 patients with implantable cardioverter-defibrillator (ICD) was examined. The 64 lead ECG system was used. Three lead sets were analyzed: 64 BSPM lead set, orthogonal lead set (XYZ) and standard 12 lead set. Patients were divided into(More)
In the work presented here we propose a new approach for the TWA modelling and detection. For this aim, the ECG amplitude modulation and the baseline wander in the ST-T segment are approximated by a scaling factor applied to the T wave added to a constant. Thanks to this simplification , the proposed global model of each ST-T segment is constituted by the(More)
The conventional spectral method is indeed a typical confidence interval computation that use normalized Fourier transform frequencies F{f} at f = 0.5. In order to get a robust detector with respect to spikes due to single-frequency tone interference and to exploit the entire frequency band to reduce the variance we proposed new parameter called SMM(More)
Inaccurate electrode placement and differences in inter-individual human anatomies can lead to misinterpretation of ECG examination. The aim of the study was to investigate the effect of precordial electrodes displacement on morphology of the ECG signal in a group of 60 patients with diagnosed cardiac disease. Shapes of ECG signals recorded from precordial(More)
In this work a simulation study of T-wave alternans is proposed in order to determine the ability of TWA detectors to quantify the performance characteristics in terms of amplitude estimation accuracy. ECG signals were simulated by repeating a single beat, and by adding four types of noise each at two different levels of power. TWA episodes with different(More)
The influence of T-wave alternans (TWA) on vectocardiographic parameters has been presented. Alternations in the length and the angle of T-wave loop vector have been found between odd and even beats in electrocardiograms with detectable T-wave alternans. The study shows the significance of changes of T-wave loop vector length and angle in the process of(More)
Vectorcardiographic representation of T-wave alternans (TWA) has been presented in new coordinate system created by means of singular value decomposition where the first axis was in T-loop direction and other axes were perpendicular. Projection of T-loop vector on the plane perpendicular to the first axis was analyzed. The study shows that in case of(More)
The aim of the study was to simulate T-wave alternans (TWA) magnitude distribution maps on the body surface employing ECGSIM program and then to compare obtained results with data measured from patients. The toolbox for ECGSIM program was developed for TWA simulation. Graphical representation of spatial distribution of TWA magnitude was implemented. Body(More)
INTRODUCTION Recent studies point to analysis of T-wave alternans as a promising indicator of an increased risk of life-threatening ventricular arrhythmias. In this study the occurrence of T-wave alternans in the high-resolution ECGs recorded during the exercise stress test and scintigraphic tests (SPECT) in patients with ischemic heart disease was(More)