The aim of the study was to assess the interaction of the cardiostimulation system of the patient and the source of electromagnetic interference (EMI) during the patient’s work by Holter monitoring of ECG. Finally, to analyze ECG recording and evaluate possible pacemaker (PCM) program responses to the presence of EMI. The observation was performed in the selected patient with the single-chamber conventional pacemaker during practicing of a profession in an industrial environment with a real risk of interaction with the defined source of interference. The heart rhythm was monitored with a standard Holter monitor and the measurement was repeated during three work shifts. The PCM was revised before each measurement and at the same time the programming was adjusted for monitoring purposes. The ECG record was back-analyzed and the device response to the presence of EMI was evaluated. No program response to the presence of an interfering electromagnetic field (EMF) was observed from the ECG recording analysis. This program response would manifest to abnormalities in the ECG curve (asynchronous pacing, pacing inhibition, competitive pacing). There were no events in the PCM memory indicating the effect of the EMI.

• MeSH
• elektrokardiografie ambulantní metody   MeSH
• elektromagnetická pole MeSH
• kardiostimulátor * MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

AIM: To describe clinical characteristics, procedural details, specific challenges, and outcomes in patients with HeartMate3TM (HM3), a left ventricular assist device system with a magnetically levitated pump, undergoing ventricular tachycardia ablation (VTA). METHODS AND RESULTS: Data were collected from patients with an HM3 system who underwent VTA in seven tertiary centres. Data included baseline patient characteristics, procedural data, mortality, and arrhythmia-free survival. The study cohort included 19 patients with cardiomyopathy presenting with ventricular tachycardia (VT) (53% with VT storm). Ventricular tachycardias were induced in 89% of patients and a total of 41 VTs were observed. Severe electromagnetic interference was present on the surface electrocardiogram. Hence, VT localization required analysis of intra-cardiac signals or the use of filter in the 40-20 Hz range. The large house pump HM3 design obscured the cannula inflow and therefore multi imaging modalities were necessary to avoid catheter entrapment in the cannula. A total of 32 VTs were mapped and were successfully ablated (31% to the anterior wall, 38% to the septum and only 9% to the inflow cannula region). Non-inducibility of any VT was reached in 11 patients (58%). Over a follow-up of 429 (interquartile range 101-692) days, 5 (26%) patients underwent a redo VT ablation due to recurrent VTA and 2 (11%) patients died. CONCLUSIONS: Ventricular tachycardia ablation in patients with HM3 is feasible and safe when done in the appropriate setup. Long-term arrhythmia-free survival is acceptable but not well predicted by non-inducibility at the end of the procedure.

• MeSH
• kardiomyopatie * etiologie   MeSH
• katetrizační ablace * škodlivé účinky   metody   MeSH
• komorová tachykardie * diagnóza   chirurgie   MeSH
• lidé MeSH
• podpůrné srdeční systémy * MeSH
• recidiva MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Polypyrrole one-dimensional nanostructures (nanotubes, nanobelts and nanofibers) were prepared using three various dyes (Methyl Orange, Methylene Blue and Eriochrome Black T). Their high electrical conductivity (from 17.1 to 60.9 S cm-1), good thermal stability (in the range from 25 to 150 °C) and resistivity against ageing (half-time of electrical conductivity around 80 days and better) were used in preparation of lightweight and flexible composites with silicone for electromagnetic interference shielding in the C-band region (5.85-8.2 GHz). The nanostructures' morphology and chemical structure were characterized by scanning electron microscopy, Brunauer-Emmett-Teller specific surface measurement and attenuated total reflection Fourier-transform infrared spectroscopy. DC electrical conductivity was measured using the Van der Pauw method. Complex permittivity and AC electrical conductivity of respective silicone composites were calculated from the measured scattering parameters. The relationships between structure, electrical properties and shielding efficiency were studied. It was found that 2 mm-thick silicone composites of polypyrrole nanotubes and nanobelts shield almost 80% of incident radiation in the C-band at very low loading of conductive filler in the silicone (5% w/w). Resulting lightweight and flexible polypyrrole composites exhibit promising properties for shielding of electromagnetic interference in sensitive biological and electronic systems.

• MeSH
• azosloučeniny chemie   MeSH
• elektromagnetické záření * MeSH
• methylenová modř chemie   MeSH
• mikroskopie elektronová rastrovací MeSH
• nanostruktury chemie   účinky záření   ultrastruktura   MeSH
• nanotrubičky chemie   účinky záření   ultrastruktura   MeSH
• nanovlákna chemie   účinky záření   MeSH
• polymery chemie   účinky záření   MeSH
• pyrroly chemie   účinky záření   MeSH
• silikony chemie   účinky záření   MeSH
• Publikační typ
• časopisecké články MeSH

The study deals with the interdisciplinary topic of the electromagnetic compatibility of the cardiac implantable electronic devices that are used in patients with a defect of heart conduction system. We are focusing on the detection of disturbing signals on electrodes of cardiostimulation device and its interpretation. The detection of electromagnetic interference (EMI) is related to electrode choice, device placement, its configuration and programming. The aim of the study is the analysis of the pacemaker response in the presence of an external source of the disturbance fields. We point to possible risks of its interaction and discuss mechanisms that can influence the pacemaker sensitivity to EMI. Due to improper signal detection, the device programming changes can occur. We present an experiment of the exposure of the cardiostimulation system to a low-frequency harmonic interference signals and finally we analyse similar clinical episode and discuss proper functioning of the pacemaker.

• MeSH
• elektrofyziologie MeSH
• elektromagnetické jevy * MeSH
• kardiostimulace umělá MeSH
• kardiostimulátor * MeSH
• lidé MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

• MeSH
• nádory radioterapie   MeSH
• nukleární lékařství metody   MeSH
• radioterapie metody   MeSH
• Publikační typ
• učebnice MeSH

• Konspekt
• Učební osnovy. Vyučovací předměty. Učebnice
• Lékařské vědy. Lékařství
• NLK Obory
• radiologie, nukleární medicína a zobrazovací metody
• onkologie
• NLK Publikační typ
• kolektivní monografie

Effects of low-frequency electromagnetic fields (LF EMF) on the activation of different tissue recovery processes have not yet been fully understood. The detailed quantification of LF EMF effects on the angiogenesis were analysed in our experiments by using cultured human and mouse endothelial cells. Two types of fields were used in the tests as follows: the LF EMF with rectangular pulses, 340-microsecond mode at a frequency of 72 Hz and peak intensity 4 mT, and the LF EMF with sinusoidal alternating waveform 5 000 Hz, amplitude-modulated by means of a special interference spectrum mode set to a frequency linear sweep from 1 to 100 Hz for 6 s and from 100 Hz to 1 Hz return also for 6 s, swing period of 12 second. Basic parameters of cultured cells measured after the LF EMF stimulus were viability and proliferation acceleration. Both types of endothelial cells (mouse and human ones) displayed significant changes in the proliferation after the application of the LF EMF under conditions of a rectangular pulse mode. Based on the results, another test of the stimulation on a more complex endothelial-fibroblast coculture model will be the future step of the investigation.

• MeSH
• elektromagnetická pole * MeSH
• elektromagnetické jevy MeSH
• endoteliální buňky pupečníkové žíly (lidské) fyziologie   MeSH
• endoteliální buňky fyziologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• myši MeSH
• viabilita buněk fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Extracellular microelectrode recording (MER) is a prominent technique for studies of extracellular single-unit neuronal activity. In order to achieve robust results in more complex analysis pipelines, it is necessary to have high quality input data with a low amount of artifacts. We show that noise (mainly electromagnetic interference and motion artifacts) may affect more than 25% of the recording length in a clinical MER database. NEW METHOD: We present several methods for automatic detection of noise in MER signals, based on (i) unsupervised detection of stationary segments, (ii) large peaks in the power spectral density, and (iii) a classifier based on multiple time- and frequency-domain features. We evaluate the proposed methods on a manually annotated database of 5735 ten-second MER signals from 58 Parkinson's disease patients. COMPARISON WITH EXISTING METHODS: The existing methods for artifact detection in single-channel MER that have been rigorously tested, are based on unsupervised change-point detection. We show on an extensive real MER database that the presented techniques are better suited for the task of artifact identification and achieve much better results. RESULTS: The best-performing classifiers (bagging and decision tree) achieved artifact classification accuracy of up to 89% on an unseen test set and outperformed the unsupervised techniques by 5-10%. This was close to the level of agreement among raters using manual annotation (93.5%). CONCLUSION: We conclude that the proposed methods are suitable for automatic MER denoising and may help in the efficient elimination of undesirable signal artifacts.

• MeSH
• artefakty * MeSH
• evokované potenciály fyziologie   MeSH
• Fourierova analýza MeSH
• hluk MeSH
• lidé MeSH
• mikroelektrody škodlivé účinky   MeSH
• mozek cytologie   MeSH
• neurony fyziologie   MeSH
• počítačové zpracování signálu * MeSH
• support vector machine MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Cílem práce je poskytnout přehled současných poznatků a doporučení vztahujících se k nejčastěji tradovaným kontraindikacím elektromyografie (EMG), tedy implantovanému kardiostimulátoru/defibrilátoru či užívání chronické antikoagulační nebo antiagregační terapie, a komplikacím EMG (infekce, pneumotorax, kompartment syndrom, poranění periferního nervu). Z publikovaných studií vyplývá, že u pacientů s implantovaným kardiostimulátorem/defibrilátorem lze bez problémů provádět běžnou i repetitivní elektrickou stimulaci periferních nervů. Je však vhodné vyhnout se místům v blízkosti těchto zařízení, a to s ohledem na možnou interferenci s jejich funkcí. Antikoagulační ani antiagregační terapie nepředstavuje dle provedených studií systematicky zvýšené riziko rozvoje klinicky významných intramuskulárních krvácení. Hematomy, detekované v návaznosti na jehlovou EMG, jsou většinou velmi drobné (několik milimetrů) a klinicky asymptomatické. Symptomatická a asymptomatická krvácení se po provedené jehlové EMG mohou vyskytovat i bez souvislosti s medikací, interferující s krevní srážlivostí. Jsou však obecně málo časté a jehlová EMG je považována za bezpečnou vyšetřovací metodu. Vysazení terapie ovlivňující srážení krve z důvodů EMG vyšetření představuje pro pacienta jednoznačně vyšší riziko než provedení jehlové EMG u pacienta při trvající antikoagulační/antiagregační terapii. Ostatní výše jmenované komplikace EMG jsou raritní, je však nutno počítat s možností jejich rozvoje a maximalizovat technická a hygienicko-epidemiologická opatření k zábraně jejich vzniku a uvážlivě indikovat EMG vyšetření.

Clinical electromyography (EMG) is a key diagnostic tool in many neuromuscular diseases. Despite this, many laboratories do not perform nerve conduction studies (NCS) in patients with a pacemaker or implantable cardioverter-defibrillator. Furthermore, some labs do not perform needle EMG or at least do not examine some of the higher risk muscle groups in patients on anticoagulant or even antiplatelet therapy. In rare cases, EMG examination may also be complicated by leakage, transmission of infectious diseases, pneumothorax, compartment syndrome, or a peripheral nerve lesion. The aim of this study was to summarize current knowledge and recommendations related to these limitations and complications of EMG examination. According to published studies, common as well as repetitive electrical peripheral nerve stimulation can be performed in patients with pacemaker/defibrillator. Stimulation in close proximity to pacemaker/defibrillator should be avoided to prevent electromagnetic interference with their function. No increased systemic risk of clinically significant intramuscular haemorrhage was found in patients on an anticoagulant or antiplatelet therapy. Intramuscular hematomas resulting from needle EMG are usually very small (several millimetres) and clinically asymptomatic. Symptomatic and asymptomatic haemorrhages following needle EMG can occur without any relation to anticoagulant/antiplatelet therapy. However, they are generally rare and needle EMG is considered to be a safe diagnostic tool. In patients taking anticoagulation medication, thrombotic risk of discontinuing anticoagulation prior to EMG outweighs the risks associated with needle examination while on anticoagulation. All other EMG complications listed above are very rare but relevant. Therefore, it should always be carefully considered whether EMG examination is indicated. General technical and hygienic-epidemiological recommendations for EMG examination should be strictly followed to minimise the incidence of complications.

• Klíčová slova
• antikoagulační terapie, antiagregační terapie,
• MeSH
• antikoagulancia MeSH
• defibrilátory MeSH
• elektrická stimulace MeSH
• elektromyografie * kontraindikace   MeSH
• infekce MeSH
• kardiostimulátor MeSH
• krvácení MeSH
• lidé MeSH
• pneumotorax MeSH
• warfarin MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

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• Klíčová slova
• Ostatní nelékařské profese, Teoretické obory, Teoretické obory,
• MeSH
• biofyzika MeSH
• elektromagnetické záření MeSH
• fyzika MeSH

• NLK Obory
• fyzika, biofyzika

Potřebujete udělat zkoušku z fyziky? Potřebujete základy fyziky k pochopení vašeho medicínského oboru? Pak je tato kniha určena právě pro Vás!

• MeSH
• biofyzika MeSH
• elektromagnetické záření MeSH
• fyzika MeSH
• Publikační typ
• monografie MeSH

• Konspekt
• Fyzika
• NLK Obory
• fyzika, biofyzika