O tempo para 1,0mm de depressão do segmento ST (T-1,0mm) adotado para caracterizar o fenômeno do aquecimento, uma expressão do precondicionamento isquêmico (PCI), em testes ergométricos sequenciais é consistente e reprodutível, porém, possui várias limitações. O objetivo deste estudo foi aplicar um escore eletrocardiográfico de isquemia miocárdica em testes ergométricos sequenciais comparando com o clássico índice T-1,0mm. Avaliamos 61 pacientes, com idade média de 62,2+7,5 anos, 86,9% homens, portadores de diabetes mellitus tipo 2 e coronariopatia multiarterial. Foram analisados 151 exames, destes 116 de pacientes completaram as duas fases de avaliação. A primeira fase compreendia dois testes ergométricos sequenciais para documentação do PCI e a segunda fase, após 1 semana, mais dois testes sob efeito de repaglinida oral. Dois observadores aplicaram o escore de forma cega. Observou-se concordância perfeita inter e intraobservador (Kendall Tau-b = 0,96, p<0,0001, Kendall Tau-b=0,98, p<0,0001, respectivamente). Os valores de sensibilidade, especificidade, valor preditivo negativo, valor preditivo positivo e acurácia, foram respectivamente de 72,41%, 89,29%, 75,8%, 87,5% e 81%. Concluímos que o escore de isquemia é um método consistente e reprodutível para documentação do fenômeno do aquecimento, representando uma alternativa factível ao índice T-1,0mm. / The time to 1.0mm ST-segment depression (T-1.0mm), adopted to document the warm-up phenomenon, an expression of the ischemic preconditioning (IPC), during sequential exercise tests is considered reliable and reproductible, although with several limitations. The main goal of this study was to apply an electrocardiographic ischemic myocardium score to sequential exercise tests, comparing with the standard T-1.0mm. We evaluated 61 patients, mean age 62,2+7,5 years-old, 86.9% male, with type 2 diabetes mellitus and multivessel coronary disease. We analyzed 151 exercise tests, being 116 tests from patients who fulfilled the two phases of the study. The first phase enrolled the patients for two sequential exercise tests to document the IPC and the second phase, after 1 week, two additional sequential exercise tests were performed under repaglinide treatment. We observed a perfect concordance inter and intraobserver (Kendall Tau-b=0.96, p<0.0001; Kendall Tau-b=0,98, p<0,0001, respectively). The sensibility, specificity, positive predictive value and negative predictive value were also determined: 72.41%, 89.29%, 75.8%, 87.5% and 81%, respectively. In conclusion, the electrocardiographic ischemic score is a consistent and reproductible tool to document the warm-up phenomenon, representing a reliable alternative to the T-1.0mm.

O fenômeno do precondicionamento isquêmico é definido como o aumento da tolerância à isquemia e à lesão de reperfusão, induzida por curtos e sucessivos episódios de isquemia prévios a período de isquemia prolongada. A angina do aquecimento e a de pré-infarto são duas condições clínicas relacionadas ao precondicionamento. Este fenômeno apresenta duas fases distintas, clássica ou precoce e tardia. A atenuação do infradesnível do segmento ST provocada pelo precondicionamento precoce está bem documentada, porém sua expressão cintilográfica permanece controversa. O objetivo desta pesquisa foi avaliar se as atenuações eletrocardiográficas do precondicionamento durante testes sequenciais estão associadas a modificações simultâneas das imagens de cintilografia de perfusão miocárdica em indivíduos com doença coronariana. Vinte e três pacientes foram selecionados entre março de 2009 e julho de 2011. A média de idade foi 64,5 anos (dp=7,0), 19 (82,6%) do sexo masculino e todos tinham lesão coronária em pelo menos um vaso superior a 60%. A medicação antiisquêmica foi suspensa por três a cinco dias. Os pacientes foram submetidos a três testes ergométricos a partir do exame de seleção, sendo dois deles sequenciais e o terceiro realizado após sete dias. A injeção do radiofármaco sestamibi-Tc-99m no teste de precondicionamento e contraprova foi administrado no tempo de aparecimento do infradesnível de ST de -2,0 mm na derivação MC5 e/ou dor precordial anotados no teste inicial ou de seleção. A imagem cintilográfica foi adquirida entre 60 a 90 minutos após o esforço. Os resultados do segundo teste (precondicionamento) mostraram aumento significativo do tempo para o aparecimento da depressão do segmento ST de 1,0 mm (338±130) e 2,0 mm (431±126), em relação ao teste inicial (245±96; 366±103) p<0,001. A diferença na redução do valor máximo de infradesnível de ST entre os três testes foi significativa (3,8±0,8; 2,3±0,6; 3,1±1,0) p<0,001. Houve redução significativa nos escores de perfusão de estresse (p=0,045) entre o primeiro e o segundo testes, bem como para o escore da diferença entre o estresse e repouso (p= 0,03), sem diferença na extensão da área de isquemia entre as três etapas detectadas pela cintilografia (p=0,691). Em conclusão, houve redução significativa das alterações eletrocardiográficas induzidas pelo precondicionamento isquêmico precoce em maior proporção do que as observadas nas respectivas imagens de cintilografia de perfusão miocárdica; não se observou associação entre a redução da depressão do ST e a redução do escore de perfusão na fase de precondicionamento, nem correlação entre a magnitude do infradesnível máximo de ST e a redução do escore de perfusão (r=0,07 e p=0,75). / The phenomenon of ischemic preconditioning is defined as the increase of tolerance to ischemia and injury of reperfusion induced by short and consecutive episodes of isquemia prior to prolonged arterial occlusion. Warm-up and pre-infarction angina are two clinical conditions regarding this phenomenon. The ischemic preconditioning has two distinct windows designed as classical and late. The improvement of ST depression induced by classical preconditioning is well documented, however its scintigraphy expression is still controversial. The aim of this research was to assess whether the reduction of ST depression induced by preconditioning during these sequencial exercise testing are associated to simultaneous alterations of the scintigraphy images of myocardial perfusion in individuals with coronary artery disease. From March 2009 to July 2011, 23 patients were selected, mean age 64,5 (sd=7,0), 19(82,6%) male. All patients had coronary artery stenosis at least 60% in one vessel. The anti ischemic therapy was discontinued for three days. Patients underwent three exercises testing after screening process; two of these tests were in a sequence and the other one performed after seven days. Tc-99m-sestamibi radiotracer injection was applied in the preconditioning test as well as for the third test at the time of development of ST depression 2,0 mm in the CM5 lead and/or chest pain estabilished in the screening process or first test. The scintigraphy image was obtained from 60 to 90 minutes after exertion. The results of the preconditioning test showed a significant increase of time for manifestation of the ST depression 1,0 mm (338±130) and 2,0 mm (431±126) regarding the first test (245±96; 366±103), p<0,001. There was a significant difference in the decrease of maximum value of ST depression among the three tests (3,8±0,8; 2,3±0,6; 3,1±1,0), p<0,001. A significant reduction in stress perfusion score (p=0,045) occurred between the first and second test as well as for the difference score between stress and rest (p=0,03). However, there was not a significant difference in the total defect size among the three stages detected by myocardial scintigraphy (p=0,691). In conclusion, there was a significant decrease of electrocardiographic alterations resulting from early preconditioning in greater proportion than the observed in scintigraphy images. It was not observed an association between the decrease of ST depression with the stress perfusion score during the preconditioning period nor the correlation between the magnitude of the maximum value of ST depression and the decrease of perfusion score (r=0,07 and p=0,75).

Abstract Vectorcardiography (VCG) determines the direction and magnitude of the heart’s electrical forces. Interpretation of the digital three-dimensional vectorcardiography in clinical applications requires robust methods and novel approaches for calculating the vectorcardiographic features. This dissertation aimed to develop new methods for vectorcardiographic signal processing. The robustness of selected pre-processing and feature extraction algorithms was improved, novel methods for detecting the injured myocardial tissue from electrocardiogram (ECG) were devised, and dynamical behavior of vectorcardiographic features was determined. The main results of the dissertation are: (1) Digitizing process and proper filtering did not produce significant distortions for dipolar Singular Value Decomposition -based ECG parameters from a diagnostic viewpoint, whereas non-dipolar parameters were very sensitive to the pre-processing operations. (2) A novel method for estimating the severity of the myocardial infarction (MI) was developed by combining the action potential based computer model and 12-lead ECG patient data. Using the method it is possible to calculate an approximate estimate of the maximum troponin value and therefore the severity of the MI. In addition, the size and location of the myocardial infarction was found to affect diagnostic significant Total-cosine-R-to-T parameter (TCRT) - changes, both in the simulations and in the patient study. (3) Furthermore, the results showed that carefully targeted improvements to the basic algorithm of the TCRT parameter can evidently decrease the number of algorithm-based failures and therefore improve the diagnostic value of TCRT in different patient data. (4) Finally, a method for calculating beat-to-beat vectorcardiographic features during exercise was developed. It was observed that the breathing affects the beat-to-beat variability of all the QRS/T angle measures and the trend of the TCRT parameter during exercise was found to be negative. Further, the results of the thesis clearly showed that the QRS/T angle measures exhibit a strong correlation with the heart rate in individual subjects. The results of the dissertation highlight the importance of robust algorithms in a VCG analysis. The results should be taken into account in further studies, so that the vectorcardiography can be utilized more effectively in clinical applications. / Tiivistelmä Vektorikardiorgafia (VKG) kuvaa sydämen sähköisen toiminnan suuntaa ja suuruutta sydämen lyönnin eri vaiheissa. Vektorikardiogrammin onnistunut tulkinta kliinisissä sovelluksissa edellyttää luotettavia menetelmiä ja uusia lähestymistapoja vektorikardiografisten piirteiden laskennassa. Tämän väitöskirjan tavoitteena oli kehittää uusia vektorikardiografisia signaalinkäsittelymenetelmiä. Väitöstyössä parannettin tiettyjen elektrokardiorgafisen (EKG) -signaalin esikäsittelyvaiheiden ja piirteentunnistusalgoritmien luotettavuutta, kehitettiin uusia menetelmiä vaurioituneen sydänlihaskudoksen tunnistamiseen EKG-signaalista, sekä tutkittiin vektorikardiografisten piirteiden dynaamista käyttäytymistä. Väitöskirjan päätulokset voidaan tiivistää seuraavasti: (1) Paperitallenteisten EKG-tallenteiden digitointiprosessi ja EKG-signaalin asianmukainen suodatus ei aiheuta diagnostisesti merkittäviä vääristymiä ns. dipolaarisiin singulaariarvohajotelmaan (SVD) perustuviin EKG-parametreihin. Kuitenkin ns. ei-dipolaariset herkemmät parametrit ovat sensitiivisiä näille esikäsittelyvaiheille. (2) Väitöskirjatyössä kehitettiin uusi menetelmä sydäninfarktin vakavuuden arvioimiselle 12-kanavaisesta EKG-signaalista käyttäen aktiopotentiaaleihin perustuvaa tietokonemallia. Väitöstyössä todettiin, että menetelmää käyttäen on mahdollista laskea karkea estimaatti kliinisessä käytössä olevalle maksimaaliselle troponiiniarvolle, joka kertoo vaurion määrästä sydänlihaskudoksessa. Lisäksi sydäninfarktin koon ja sijainnin havaittiin vaikuttavan vektorikardiografiseen de- ja repolarisaation suhdetta kuvaavaan diagnostisesti merkittävään Total-cosine-R-to-T- (TCRT) muuttujaan. (3) Tulokset osoittivat myös, että tekemällä muutamia pieniä parannuksia alkuperäiseen TCRT-parametrin algoritmiin, voidaan merkittävästi vähentää parametrin laskennassa aiheutuvia vääristymiä ja täten parantaa TCRT-parametrin diagnostista arvoa erilaisissa potilasaineistoissa. (4) Neljänneksi, työssä kehitettiin menetelmä, jolla vektorikardiografisia piirteitä laskettiin dynaamisesti lyönti lyönniltä. Hengityksen havaittiin aiheuttavan rasitustestin aikana merkittävää lyöntikohtaista vaihtelua. Työssä havaittiin myös, että niin TCRT-parametrilla kuin myös muillakin de- ja repolarisaation välistä suhdetta kuvaavilla muuttujilla oli selvä korrelaatio sydämen sykkeen kanssa. Väitöskirjan tulokset korostavat luotettavien algoritmien tärkeyttä vektorikardiografisessa analyysissä. Tulosten huomioiminen jatkotutkimuksissa edesauttaa vektorikardiografian hyödyntämistä kliinisissä sovelluksissa.

The goal of this thesis is to investigate if it is possible to use measurements of physiological parameters to accelerate learning of target shooting for novice marksmen in Saab’s Ground combat indoor trainer (GC-IDT). This was done through a literature study that identified brain activity, eye movements, heart activity, muscle activity and breathing as related to shooting technique. The sensors types Electroencephalography (EEG), Electroocculography (EOG), Electrocardiogram (ECG), Electromyography (EMG) and impedance pneumography (IP) were found to be suitable for measuring the respective parameters in the GC-IDT. The literature study also showed that previous studies had found differences in the physiological parameters in the seconds leading up to the shot when comparing experts and novices. The studies further showed that it was possible to accelerate learning by giving feedback to the novices about their physiological parameters allowing them to mimic the behavior of the experts. An experiment was performed in the GC-IDT by measuring EOG, ECG, EMG and IP on expert and novice marksmen to investigate if similar results as seen in previous studies were to be found. The experiment showed correlation between eye movements and shooting score, which was in line with what previous studies had shown. The respiration measurement did not show any correlation to the shooting scores in this experiment, it was however possible to see a slight difference between expert and novices. The other measurements did not show any correlation to the shooting score in this experiment. In the future, further experiments needs to be made as not all parameters could be explored in depth in this experiment. Possible improvements to such experiments are i.e. increasing the number of participants and/or the number of shots as well as marking shots automatically in the data and increasing the time between shots.

O sistema Holter é considerado padrão ouro para detecção de arritmias cardíacas, possibilitando o seu diagnóstico e sua relação com os sintomas do paciente. As novas gerações de marcapassos (MP) detectam e registram eletrogramas intracavitários e poderiam dispensar o Holter no seguimento dos pacientes. Os diferentes MP dispõem de algoritmos de detecção de arritmias ventriculares (AV) que variam de acordo com o modelo e sua correlação diagnóstica com Holter foi pouco estudada. O objetivo desse estudo foi avaliar 1. a correlação entre o monitor de eventos dos MP e do Holter na detecção de AV e 2. a concordância das AV detectadas nos dois sistemas. Foram estudados129 pacientes portadores de MP com função de detecção de arritmias, com idade média de 68,6+19.1 anos (entre 19 e 94), 54,8% do sexo feminino. Os pacientes foram submetidos à monitorização com Holter por 72 horas. Assim que o sistema foi ligado, os contadores de eventos dos marcapassos foram reiniciados e os relógios sincronizados, para que ambos os sistemas detectassem os eventos simultaneamente. Os MP foram programados para detecção de eventos com o menor valor de frequência ventricular (FV) e o menor número de batimentos sequenciais (BT) possíveis. Depois de 72 horas, os sistemas Holter foram retirados e os registros analisados, assim como os registros simultâneos dos gravadores dos MP. Foram qualificados como eventos arrítmicos no Holter e MP, respectivamente: EV isoladas e \"PVC\"; extra-sístoles em pares e \"couplets\"; TVNS (> 3BT) e \"triplets\"(3BT), \"runs\"(3 a 8 ou > 8 BT) e \"HVR\" (3 ou 4 BT). As correlações de Spearman foram utilizadas para avaliar se o marcapasso acompanha a detecção dos parâmetros do Holter. Os coeficientes de correlação intraclasse e os respectivos intervalos com 95% de confiança, calculados para avaliar a concordâncias entre os parâmetros equivalentes do marcapasso e do Holter. Foram calculados os coeficientes Kappa para avaliar a concordância na detecção de > 10 \"PVC\"/h com > 10 EV/h. Resultados: Os monitores dos marcapassos subestimaram o Holter. Os registros de \"PVC\", \"triplet\" e \"HVR\" por TVNS apresentaram correlações positivas em relação aos parâmetros do Holter, sendo a mais alta aquela entre \"PVC\" e EV (r=0,501). Porém, a concordância entre os tipos de arritmias detectadas foi baixa (CCI < 0,5), exceção feita à concordância de \"triplet\" com TVNS de três batimentos (CCI=0.984). A concordância na detecção de mais de 10 PVC/h e mais de 10 EV/h foi moderada (kappa= 0,483), embora para os MP da Medtronic, o coeficiente de concordância foi alto (kappa=0.877). Para os MP com algoritmo de detecção de sequências de três batimentos com FV menor que 140bpm ( < 140/3), a correlação entre HVR e TVNS foi expressiva (r = 1), sendo a concordância entre esses parâmetros também bastante alta (CCI = 0,800). Conclusões: A correlação e a concordância na detecção de AV registradas nos MP e no Holter foram inconsistentes. Padronização dos algoritmos de detecção de AV, semelhantes os do sistema Holter, é necessária para que os pacientes portadores de dispositivos implantáveis possam se beneficiar dessa função para seguimento clínico e estratificação de risco / The Holter monitoring is considered the gold standard method for detection of cardiac arrhythmias, enabling its diagnosis and its correlation with the patient\'s symptoms. New generations of artificial pacemakers can detect and record intracavitary electrograms and, theoretically, could discard the Holter during the follow-up of the patients. Pacemakers have different ventricular arrhythmias (VA) detection algorithms, varying according to the model. Their diagnosis capacity comparing to Holter monitoring has been poorly studied. The aim of this study was to evaluate 1. the correlation between the event monitor of the pacemaker and the Holter in VA detection and 2. the agreement between the VA detected in both systems. We studied 129 patients with implanted pacemakers, which had arrhythmia detection function, mean age of 68.6 + 19.1 years (19 to 94), 54.8% female. The patients underwent Holter monitoring for 72 hours. Once the system was connected, event counters of pacemakers were reset and the clocks synchronized, so that both systems could detect the arrhythmic events simultaneously. The pacemakers were programmed to detect events with the lowest ventricular rate and lowest number of sequential beats allowed for each model. After 72 hours, Holter systems were removed and the records analyzed, as well as the simultaneous records of the pacemakers. Were considered as arrhythmic events: PVC isolated (in the pacemaker described as \"PVC\"); premature beats in pairs (pacemaker described as \"couplets\"); NSVT (pacemaker described as \"triplets\"- 3beats, \"runs\"- 4 to 8 or > 8 beats and \"HVR\"- 3 to 4 beats). Spearman rank correlations were used to assess whether the pacemaker and Holter identified the same parameters. The intraclass correlation coefficients and the respective intervals with 95% confidence were calculated to evaluate the concordance between the equivalent parameters of the pacemaker and Holter. Kappa coefficients were calculated to assess the agreement in the detection of > 10 PVC/h by the pacemakers and by the Holter. Results: The pacemakers underestimated the arrhythmias detection of Holter. Records of \"PVC\", \"triplet\" and \"HVR\" by NSVT showed positive correlations with the Holter parameters, and the highest one was among \"PVC\" and EV (r = 0.501). The agreement between the types of arrhythmias detected was quite low (CCI < 0.5), except for \"triplet\" detected by pacemakers and three beats NSVT by Holter (ICC = 0.984). The correlation detection for more than 10 PVC /h was moderate (kappa = 0.483), except for Medtronic pacemakers (kappa=0.877). When the pacemaker was programmed to detect sequences of three beats with heart rate lower than 140bpm ( < 140/3), the correlation between HVR and NSVT was perfect (r = 1) and the agreement between these parameters was also quite high (ICC = 0.800). Conclusions: The correlation and agreement between pacemakers and Holter monitoring in the detection of VA were not consistent. A standardization of the pacemakers\' detection algorithms is necessary before using this function for clinical follow-up and risk stratification of the patients

A hipertrofia ventricular esquerda (HVE) é importante fator de risco cardiovascular. O objetivo deste estudo retrospectivo foi verificar a associação de critérios eletrocardiográficos de HVE com as características anatômicas e histológicas do coração, em 51 pacientes submetidos à necropsia. Procedeu-se à medição do diâmetro transverso dos cardiomiócitos e da porcentagem de fibrose do ventrículo esquerdo e direito. Entre os pacientes que apresentavam HVE anatômica, o critério de Romhilt foi positivo em 92,3%, sendo superior aos demais critérios avaliados, com especificidade de 89,5% e sensibilidade de 68,8%, Foi o único que se associou a características anatômicas e histológicas do coração / The left ventricular hypertrophy (LVH) is an important cardiovascular risk factor. The purpose of the present retrospective paper is to examine the association of LVH electrocardiographic criteria with both anatomical and histological characteristics of the heart on 51 patients submitted to the necropsy. The study carried out the measurement of the transverse diameter of cardiomyocytes, as well as the percentage of fibrosis at both left and right ventriculi. Among those patients who presented anatomic LVH, the Romhilt criterium resulted positive in 92.3% of the cases, thus surpassing the other criteria evaluated, with specificity and sensibility up to 89.5% and 68.8% respectively. This was the only criterium associated to both anatomic and histological characteristics of the heart

INTRODUÇÃO: A terapia de ressincronização cardíaca (TRC) é procedimento já incorporado às diretrizes do tratamento da insuficiência cardíaca crônica grave. Os efeitos sobre a repolarização ventricular são controversos e seu comportamento ainda precisa ser melhor definido por meios não invasivos. OBJETIVO: Analisar o comportamento da repolarização ventricular, através do mapeamento eletrocardiográfico de superfície (MES), em pacientes sob TRC. MÉTODOS: Foram estudados 52 pacientes sob TRC com indicação classe I das Diretrizes Brasileiras de Dispositivos Cardíacos Eletrônicos Implantáveis-2007, com idade média 58,8±12,3 anos, 31 homens, FEVE:27,5±9,2 e QRS:181,5±24,2ms. Foram excluídos os que não eram classe I e também os que usavam amiodarona, portadores de fibrilação atrial, marcapasso ou CDI prévios. O MES de 87 derivações (59 no tórax anterior e 28 no dorso) foi realizado em ritmo sinusal (BASAL) e sob efeito do ressincronizador (BIV) Através de medidas semiautomáticas foram obtidos o intervalo QT, QTc médio e a dispersão de QT (DQT) global das 87 derivações, nos dois modos de estimulação, em cada paciente. As mesmas medidas foram realizadas e comparadas nas três regiões discriminadas pelo MES (VD, Septo e VE). Caracterizamos assim, o comportamento global e regional do QT e sua dispersão na TRC. Utilizamos os testes t Student pareado e ANOVA para comparações múltiplas. Nível de significância de p< 0,05. RESULTADOS: O comportamento global do QTmédio foi sensivelmente menor em BIV que no BASAL (424,4±38,7 x 455,8±46,5ms; p<0,001), assim como o QTc médio (460,7±42,3 x 483,8±41,4ms; p<0,05) e a DQT (61,2±26,2 x 74,9±28,7ms; p<0,05). O QTmédio foi semelhante nas 3 regiões nos modos BASAL e BIV (p=ns), porém o QTc médio nas regiõess VD e VE mostrou-se significantemente menor no modo BASAL. Sob BIV, essa diferença foi notavelmente menor na região do VD. A DQT, em região do VE, por sua vez, foi significantemente menor em relação ao Septo, nos dois modos (BASAL: 40,5±23,1 x 55,7±28,7ms, p<0,01 e BIV: 30,6±20,4 x 47,1±20,2ms, p<0,001). A variação de efeito (D%) da TRC determinou redução do QTmédio nas 3 regiões (VD: p=0,0014; Septo: p=0,0001 e VE: p=0,0018), enquanto a DQT reduziu-se em VD: p=0,04 e VE: p=0,023. Em região septal, a redução da DQT não atingiu significância, embora tenha mostrado a mesma tendência de resposta. CONCLUSÃO: O Mapeamento Eletrocardiográfico de Superfície detectou redução global e regional dos valores da repolarização ventricular, através da análise do QTm, QTcm e DQT, por efeito da terapia de ressincronização cardíaca em pacientes com insuficiência cardíaca grave e BRE / BACKGROUND: Cardiac resynchronization therapy (CRT) is an already established procedure, which became part of the guidelines for severe chronic heart failure treatment. Its effects upon the ventricular repolarization are controversial, therefore CRT response still remains to be better defined by noninvasive methods. OBJECTIVE: The aim of this study was to analyze the ventricular repolarization response by body surface potential mapping (BSPM) in patients undergoing CRT. METHODS: Fifty-two patients undergoing CRT, mean age 58.8±12.3 years, 31 male, LVEF 27.5±9.2 and QRS duration 181.5±14.2ms, with indication class I of the 2007Guidelines for Implantable Electronic Cardiac Devices of the Brazilian Society of Cardiology, were studied. Those who were not in class I and/or in use of amiodarone, with atrial fibrillation, or with previous pacemaker or ICD, were excluded. Eighty-seven-lead BSPM examination (59 leads on the anterior chest and 28 on the back) was performed in sinus rhythm (BASELINE), and in biventricular pacing (BIV) with the resynchronization device on. Global values of QT and mean QTc intervals, and QT dispersion (DQT) were semiautomatically measured in all patients in the two pacing modes. Same measurements were made and compared in the three regions (RV, Septum and LV) discriminated by BSPM maps. Thus we characterized the global and regional QT response and its dispersion under CRT. t-Student paired test and ANOVA were used for multiple comparisons. Significance level: p<.05. RESULTS: The global mean QT response was considerably smaller in BIV pacing than in BASELINE (424.4±38.7 x 455.8±46.5ms; p<.001), and so were the mean QTc (460.7±42.3 x 483.8±41.4ms; p<.05) and DQT (61.2±26.2 x 74.9±28.7ms; p<.05). Mean QT was similar across the three regions in both pacing modes (p=ns); however, mean QTc in RV and LV regions was found to be significantly smaller in BASELINE. In BIV pacing such difference was considerably smaller in the RV region. On the other hand, DQT value in the LV region was significantly smaller compared to the Septum region in both modes (BASELINE 40.5±23.1 x 55.7±28.7ms. p<.01; and BIV 30.6±20.4 x 47.1±20.2ms. p<.001). Variation of CRT effect (D%) determined reduction of mean QT in the three regions, RV (p=.0014); Septum (p=.0001); and LV (p=.0018), while DQT was reduced in RV (p=.04) and LV (p=.023) regions. DQT reduction in the septal region was not significant, although it showed the same trend of response. CONCLUSION: body surface potential mapping detected reduction of global and regional ventricular repolarization values by analyzing QTm, QTcm and DQT variables under the effect of cardiac resynchronization therapy, in patients with severe heart failure and LBBB

This masters thesis describes possibilities of a heart rate measuring. Several methods of measuring will be discussed. The primary objective of this paper is to design battery powered cardiotachometr with a range of 30-240 beats/min and a low battery indication. Cardiotachometer uses the R waves detector to measure heart rate. This thesis is focused on creation of the block diagram, electrical circuit, printed circuit and calculation of electronic device used in cardiotachometers.

This work deals with delineation of ECG signals. First we will become familiar with ECG and commonly used processing methods. Various transformation methods of ECG leads. Further we will describe methods of delineation ECG signals. Second part is dedicated to metod used in this work for delineation of ECG signals from CSE database. Particulary method using Dyadic Wavelet Transform. Work include, description of used program and results. Third part is dedicated to methods of ECG leads transformations and cluster analysis. In conclusion we will evaluate the results.

L’oubli est un mécanisme essentiel au fonctionnement de la mémoire. Ceci est vrai lorsque l’on considère la mémoire de l’individu, qui est l’objet privilégié de la neuropsychologie, mais cela est également le cas lorsque nous considérons les usages sociaux, culturels et historiques de la mémoire qui sont les objets d’études privilégiés de l’histoire et des sciences humaines. Dans ce travail, nous avons cherché à comprendre l’influence conjointe des capacités de contrôle inhibiteur et de l’encodage de représentations collectives sur la conservation des souvenirs épisodiques. Nous avons abordé la question de l’oubli volontaire à l’aide du paradigme "Think/No-Think" qui permet l’induction expérimentale d’intrusions mnésiques, de leur contrôle et de leur oubli. Nous avons tout d’abord montré, en électrocardiographie et en électroencéphalographie, que les capacités d’oubli volontaire influencent directement la manifestation physiologique des émotions qui peuvent leur être associées. Ce résultat a ensuite été complété par une étude, à l’aide d’analyses de classification multivariées, montrant que les dynamiques neurales qui encadrent la suppression effective des souvenirs, lorsqu’ils apparaissent involontairement à la conscience, sont comparables aux réflexes de réorientation attentionnelle qui peuvent intervenir lors d’interférences sensorielles ou perceptives. Enfin, nous abordons l’influence des schémas présents en mémoire collective sur l’encodage des souvenirs à travers une étude en imagerie par résonance magnétique fonctionnelle. / Forgetting is a central mechanism for memory functioning. This is noticeable regarding individual’s memory, which is the privileged topic of neuropsychology, but this is still the case when we consider the social, cultural and historical practices of memory which are the privileged topics of history and social sciences. In this work, we tried to understand the joint influence of inhibitory control capabilities and the encoding of collective representations over episodic memories conservation. We addressed the question of voluntary forgetting through the use of the"Think/No-Think" paradigm as a way to induce experimental memory intrusions and their control. First, we report with electrocardiography and electroencephalography that voluntary forgetting capabilities directly affects the physiological roots of associated emotions. This result was then complemented, through the use of multivariate decoding, by a study showing that the neural dynamics surrounding the effective suppression of memories, when they involuntarily intrude into consciousness, are comparable to the reorienting reflex occurring during sensory or perceptive interference. Finally, we assess the influence of collective memory schema on the encoding of memories in a magnetic resonance image study.