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Atrial fibrillation (AF) is the most sustained arrhythmia in the heart and also the most common complication developed after cardiac surgery. Due to its progressive nature, timely detection of AF is important. Currently, physicians use a surface electrocardiogram (ECG) for AF diagnosis. However, when the patient develops AF, its various development stages are not distinguishable for cardiologists based on visual inspection of the surface ECG signals. Therefore, severity detection of AF could start from differentiating between short-lasting AF and long-lasting AF. Here, de novo post-operative AF (POAF) is a good model for short-lasting AF while long-lasting AF can be represented by persistent AF. Therefore, we address in this paper a binary severity detection of AF for two specific types of AF. We focus on the differentiation of these two types as de novo POAF is the first time that a patient develops AF. Hence, comparing its development to a more severe stage of AF (e.g., persistent AF) could be beneficial in unveiling the electrical changes in the atrium. To the best of our knowledge, this is the first paper that aims to differentiate these different AF stages. We propose a method that consists of three sets of discriminative features based on fundamentally different aspects of the multi-channel ECG data, namely based on the analysis of RR intervals, a greyscale image representation of the vectorcardiogram, and the frequency domain representation of the ECG. Due to the nature of AF, these features are able to capture both morphological and rhythmic changes in the ECGs. Our classification system consists of a random forest classifier, after a feature selection stage using the ReliefF method. The detection efficiency is tested on 151 patients using 5-fold cross-validation. We achieved 89.07% accuracy in the classification of de novo POAF and persistent AF. The results show that the features are discriminative to reveal the severity of AF. Moreover, inspection of t, Signal Processing Systems

AIMS: Ventricular activation patterns can aid clinical decision-making directly by providing spatial information on cardiac electrical activation or indirectly through derived clinical indices. The aim of this work was to derive an atlas of the major modes of variation of ventricular activation from model-predicted 3D bi-ventricular activation time distributions and to relate these modes to corresponding vectorcardiograms (VCGs). We investigated how the resulting dimensionality reduction can improve and accelerate the estimation of activation patterns from surface electrogram measurements. METHODS AND RESULTS: Atlases of activation time (AT) and VCGs were derived using principal component analysis on a dataset of simulated electrophysiology simulations computed on eight patient-specific bi-ventricular geometries. The atlases provided significant dimensionality reduction, and the modes of variation in the two atlases described similar features. Utility of the atlases was assessed by resolving clinical waveforms against them and the VCG atlas was able to accurately reconstruct the patient VCGs with fewer than 10 modes. A sensitivity analysis between the two atlases was performed by calculating a compact Jacobian. Finally, VCGs generated by varying AT atlas modes were compared with clinical VCGs to estimate patient-specific activation maps, and the resulting errors between the clinical and atlas-based VCGs were less than those from more computationally expensive method. CONCLUSION: Atlases of activation and VCGs represent a new method of identifying and relating the features of these high-dimensional signals that capture the major sources of variation between patients and may aid in identifying novel clinical indices of arrhythmia risk or therapeutic outcome.

BACKGROUND: The combination of left bundle branch block (LBBB) morphology and QRS duration is currently used to select patients for cardiac resynchronization therapy (CRT). These parameters, however, have limitations. This study evaluates the value of QRS area compared with that of QRS duration and morphology in the association with clinical and echocardiographic outcomes in a large cohort of CRT patients.METHODS: A retrospective multicentre study was conducted in 1492 CRT patients. LBBB morphology, QRS duration, and QRS area in the baseline 12- lead ECG were evaluated for their association with the occurrence of the combined primary end point of all- cause mortality, cardiac transplantation, and left ventricular assist device implantation. Secondary end points were heart failure hospitalization within the first year after implantation and echocardiographic reduction in left ventricular end- systolic volume.RESULTS: During a mean follow- up period of 3.4 years, 32% of patients reached the primary end point. The association of QRS area with all outcomes was stronger than that of LBBB morphology and QRS duration separately and at least as strong as their combination. QRS area identified patients who did not experience the primary end point better than QRS morphology and QRS duration (area under the curve, 0.61 versus 0.55 and 0.51, respectively; P<0.001). Furthermore, QRS area identifies patients with echocardiographic remodeling in response to CRT better than QRS morphology and duration (area under the curve, 0.69 versus 0.58 and 0.58, respectively; P<0.001). QRS area was the only independent electrocardiographic determinant associated with the primary end point; hazard ratio, 0.50 (0.35- 0.71). Furthermore, QRS area showed significant association with outcomes in both patients with and without LBBB and QRS = 150 ms.CONCLUSIONS: QRS area has a strong association to clinical and echocardiographic response to CRT, at least as strong as cur

BACKGROUND: The combination of left bundle branch block (LBBB) morphology and QRS duration is currently used to select patients for cardiac resynchronization therapy (CRT). These parameters, however, have limitations. This study evaluates the value of QRS area compared with that of QRS duration and morphology in the association with clinical and echocardiographic outcomes in a large cohort of CRT patients.METHODS: A retrospective multicentre study was conducted in 1492 CRT patients. LBBB morphology, QRS duration, and QRS area in the baseline 12- lead ECG were evaluated for their association with the occurrence of the combined primary end point of all- cause mortality, cardiac transplantation, and left ventricular assist device implantation. Secondary end points were heart failure hospitalization within the first year after implantation and echocardiographic reduction in left ventricular end- systolic volume.RESULTS: During a mean follow- up period of 3.4 years, 32% of patients reached the primary end point. The association of QRS area with all outcomes was stronger than that of LBBB morphology and QRS duration separately and at least as strong as their combination. QRS area identified patients who did not experience the primary end point better than QRS morphology and QRS duration (area under the curve, 0.61 versus 0.55 and 0.51, respectively; P<0.001). Furthermore, QRS area identifies patients with echocardiographic remodeling in response to CRT better than QRS morphology and duration (area under the curve, 0.69 versus 0.58 and 0.58, respectively; P<0.001). QRS area was the only independent electrocardiographic determinant associated with the primary end point; hazard ratio, 0.50 (0.35- 0.71). Furthermore, QRS area showed significant association with outcomes in both patients with and without LBBB and QRS = 150 ms.CONCLUSIONS: QRS area has a strong association to clinical and echocardiographic response to CRT, at least as strong as cur

BACKGROUND: Many variants of the spatial QRS-T angle (QRS-Ta) are in use. We aimed to identify the best QRS-Ta for all-cause mortality prediction among different variants.METHODS: 6667 individuals from the Inter99 General Population Study were followed for a median of 12.7 years. Vectorcardiograms were calculated using the Kors and Inverse Dower matrices. The QRS-Ta was calculated using both mean and peak vectors of the QRS- and T-loops. Hazard ratios (HR) for abnormal QRS-Tas were calculated using a Cox's Proportional Hazard Model.RESULTS: The highest HR and largest AUC for all-cause mortality was obtained with the Kors matrix and the mean vector (HR = 2.2, 95% confidence interval: [1.38;3.43] p < 0.001, in men). There was interaction with the orientation of the QRS-T plane.CONCLUSION: For optimal prediction of all-cause mortality, the mean vectors in the QRS- and T-loops of the Kors-derived vectorcardiogram should be used. QRS-T plane orientation affects mortality prediction.

Background. In the complex treatment of myocardial infarction (MI), combined with non-alcoholic fatty liver disease (NAFLD) the application of drugs with protective properties is of current interest. The purpose of research is to study the effectiveness of Thiotriazoline and Enerliv in the complex treatment of patients with acute MI, combined with hepatic steatosis or non-alcoholic steatohepatitis. Materials and methods. The study involved 47 patients with acute MI with Q wave, combined with NAFLD. The study of electrical activity of the heart was performed on an improved polygraph with the regi­stration of electric and vectorcardiogram before and after the three-week therapy with basic drugs of 16 patients (13 men and 3 women, average age — 60,5 ± 3,74 years), with the addition of Thiotriazoline of 16 patients (8 men and 8 wo­men, average age — 62,94 ± 2,71 years), and with Thiotriazoline and essential phospholipids in combination with basic therapy of 15 patients (10 men and 5 women) aged 36 to 75 years (ave­rage age — 60,0 ± 3,36 years). Results. The treatment with basic drugs caused a further decrease in the electromotive force of the heart with the slowing of the pulse and the violation of the late repolarization process in the myocardium of the ventricles and atria with a decrease in the damage zone in the left ventricle and atrial overload. Simultaneous use of Thiotriazoline and basic drugs caused minimal positive changes in the electromotive force of the heart. In addition, the area of ischemia increased through reducing of myocardial damage zones, normalization of the left atrium became more marked, and repolarization in the atria stabilized. The use of a therapeutic complex that included basic drugs and Thiotriazoline and essential phospholi­pids contributed to a significant increase in bioelectric potentials of ventricular myocardium with the local improvement of speed parameters and a more marked recovery of cardiomyocytes in the periphery of the damaged, Актуальность. В комплексном лечении инфаркта миокарда (ИМ), сочетанного с неалкогольной жировой болезнью печени (НЖБП), актуальным является применение лекарственных средств с протективными свойствами. Цель исследования — изучить эффективность Тиотри­азолина и препарата обезжиренных обогащенных соевых фосфолипидов в комплексном лечении больных в остром периоде ИМ, сочетанного со стеатозом печени или неалкогольным стеатогепатитом. Материалы и методы. Обследовано 47 больных с острым ИМ с зубцом Q, сочетанным с НЖБП. Исследование электрической активности сердца проводилось на усовершенствованном полиграфе с регистрацией электро- и векторкардиограммы до и после трехнедельной терапии базисными препаратами 16 больных (13 мужчин и 3 женщины, средний возраст — 60,50 ± 3,74 года), с добавлением Тиотриазолина — 16 больных (8 мужчин и 8 женщин, средний возраст — 62,94 ± 2,71 года), Тиотриазолином и препаратом обезжиренных обогащенных соевых фосфолипидов в комбинации с базисной терапией — 15 больных (10 мужчин и 5 женщин) в возрасте от 36 до 75 лет (средний возраст — 60,00 ± 3,36 года). Результаты. При лечении базисными препаратами определялось дальнейшее уменьшение электродвижущей силы сердца с замедлением проведения импульса и нарушением процессов поздней реполяризации в миокарде желудочков и предсердий при уменьшении зоны повреждения в левом желудочке и перегрузки предсердий. Одновременное применение Тиотриазолина и базисных препаратов вызвало минимальные положительные сдвиги в электродвижущей силе сердца. Кроме того, отмечалось увеличение зоны ишемии за счет уменьшения зоны повреждения миокарда, более выраженная нормализация полости левого предсердия и регистрировалась стабилизация процессов реполяризации в предсердиях. Применение лечебного комплекса, в состав которого входили базисные препараты, препарат обезжиренных обогащенных соевых фосфолипидов и Тиотриазолин, способствовало значительному увеличению биопотенциалов миокарда желудочков при локальном улучшении скоростных п, Актуальність. У комплексному лікуванні інфаркту міокарда (ІМ), поєднаного з неалкогольною жировою хворобою печінки (НЖХП), актуальним є застосування лікарських засобів із протективними властивостями. Мета дослідження — вивчити ефективність Тіотриазоліну та препарату знежирених збагачених соєвих фосфоліпідів у комплексному лікуванні хворих у гострому періоді ІМ, поєднаного зі стеатозом печінки або неалкогольним стеатогепатитом. Матеріали і методи. Обстежено 47 хворих із гострим ІМ із зубцем Q, поєднаним із НЖХП. Дослідження електричної активності серця проводилося на вдосконаленому поліграфі з реєстрацією електро- та векторкардіограми до і після тритижневої терапії базисними препаратами 16 хворих (13 чоловіків і 3 жінок, середній вік — 60,50 ± 3,74 року), із доданням Тіотриазоліну — 16 хворих (8 чоловіків і 8 жінок, середній вік — 62,94 ± 2,71 року), Тіотриазоліном та препаратом знежирених збагачених соєвих фосфоліпідів у комбінації з базисною терапією — 15 хворих (10 чоловіків і 5 жінок) віком від 36 до 75 років (середній вік — 60,00 ± 3,36 року). Результати. Під час лікування базисними препаратами спостерігалося подальше зменшення електрорушійної сили серця з уповільненням проведення імпульсу та порушенням процесів пізньої реполяризації в міокарді шлуночків і передсердь за зменшення зони пошкодження в лівому шлуночку й перевантаження передсердь. Одночасне застосування Тіотриазоліну та базисних препаратів спричинило мінімальні позитивні зрушення в електрорушійній силі серця. Крім того, відзначалося збільшення зони ішемії за рахунок зменшення зони пошкодження міокарда, більш виражена нормалізація порожнини лівого передсердя та реєструвалася стабілізація процесів реполяризації в передсердях. Застосування лікувального комплексу, до складу якого входили базисні препарати, Тіотриазолін і препарат знежирених збагачених соєвих фосфоліпідів, сприяло знач­ному збільшенню біопотенціалів міокарда шлуночків за локального поліпшення швидкісних показників і більш вираженому відно

[ES] El síndrome de Brugada (SBr) causa muerte súbita en pacientes con corazones estructuralmente normales. El SBr se diagnostica en base a los antecedentes clínicos y familiares del paciente junto con un electrocardiograma característico (ECG tipo I): una elevación del segmento ST en forma de cueva por encima de 0,2 mV en las derivaciones precordiales derechas (se refiere al él como ECG tipo I). Sin embargo, el patrón del ECG de los pacientes con SBr es dinámico, y por lo tanto hay una probabilidad del 25% de registrar un ECG tipo I en un paciente con SBr, por lo tanto el diagnóstico actual mediante el ECG carece de sensibilidad. Los pacientes con SBr presentan características especiales en el ECG, incluso en ausencia de un ECG tipo I. El objetivo de esta tesis ha sido determinar qué características espacio-temporales de los ECG de pacientes con SBr pueden permitir un aumento en la sensibilidad del diagnóstico basado en el ECG. Hemos encontrado que la duración y la orientación de las ondas R' en el ECG permiten discriminar entre los pacientes con SBr sin un ECG de tipo I vs sujetos sin SBr con una sensibilidad del 75%, aumentando en 50% la sensibilidad de los actuales criterios electrocardiográficos., [EN] Brugada syndrome (BrS) causes sudden death in patients with structurally normal hearts. BrS is diagnosed based on clinical and family history of the patient along with a characteristic electrocardiogram (Type I ECG): a cave-shaped ST segment elevation above 0.2 mV in right precordial leads (referred to as type I ECG). However, the ECG pattern of BrS patients is dynamical, and thus there is a 25% chance of recording a type I ECG from a BrS patient, and so current ECG diagnosis lacks sensitivity. BrS patients present special ECG characteristics, even in absence of a type I ECG. The objective of this thesis was to determine which spatio-temporal characteristics of the ECGs of BrS patients may allow to increase the sensitivity of the ECG-based diagnosis. We have found that the duration and orientation of terminal R waves on the ECG allow to discriminate between non-type I BrS vs. non BrS subjects with a sensitivity of 75%, increasing in 50% the sensitivity of current ECG criteria

Measurements of the Q-T interval are less reliable in children than in adults. Identification of superior diagnostic tools is warranted. This study aimed to investigate whether a vectorcardiogram (VCG) recorded from three orthogonal leads (X, Y, Z) according to Frank is superior to a 12-lead electrocardiogram (ECG) in providing a correct long Q-T syndrome (LQTS) diagnosis in children. This LQTS group consisted of 35 genetically confirmed carriers of mutations in the KCNQ1 (n = 29) and KCNH2 (n = 6) genes. The control group consisted of 35 age- and gender-matched healthy children. The mean age was 7 years in the LQTS group and 6.7 years in the control group (range, 0.5-16 years). The corrected Q-T interval (QT(c)) was measured manually (QT(man)) by one author (A.W.). The 12-lead ECG automatic measurements (QT(ECG)) and interpretation (QT(Interpret)) of QT(c) were performed with the Mac5000 (GE Medical System), and the VCG automatic measurements (QT(VCG)) were performed with the Mida1000, CoroNet (Ortivus AB, Sweden). By either method, a QT(c) longer than 440 ms was considered prolonged and indicative of LQTS. Of the 35 children with genetically confirmed LQTS, 30 (86 %) received a correct diagnosis using QT(VCG), 29 (82 %) using QT(man), 24 (69 %) using QT(ECG), and 17 (49 %) using QT(Interpret). Specificity was 0.80 for QT(VCG), 0.83 for QT(man), 0.77 for QT(ECG), and 0.83 for QT(Interpret). The VCG automatic measurement of QT(c) seems to be a better predictor of LQTS than automatic measurement and interpretation of 12-lead ECG.

[ES] El síndrome de Brugada (SBr) causa muerte súbita en pacientes con corazones estructuralmente normales. El SBr se diagnostica en base a los antecedentes clínicos y familiares del paciente junto con un electrocardiograma característico (ECG tipo I): una elevación del segmento ST en forma de cueva por encima de 0,2 mV en las derivaciones precordiales derechas (se refiere al él como ECG tipo I). Sin embargo, el patrón del ECG de los pacientes con SBr es dinámico, y por lo tanto hay una probabilidad del 25% de registrar un ECG tipo I en un paciente con SBr, por lo tanto el diagnóstico actual mediante el ECG carece de sensibilidad. Los pacientes con SBr presentan características especiales en el ECG, incluso en ausencia de un ECG tipo I. El objetivo de esta tesis ha sido determinar qué características espacio-temporales de los ECG de pacientes con SBr pueden permitir un aumento en la sensibilidad del diagnóstico basado en el ECG. Hemos encontrado que la duración y la orientación de las ondas R' en el ECG permiten discriminar entre los pacientes con SBr sin un ECG de tipo I vs sujetos sin SBr con una sensibilidad del 75%, aumentando en 50% la sensibilidad de los actuales criterios electrocardiográficos., [EN] Brugada syndrome (BrS) causes sudden death in patients with structurally normal hearts. BrS is diagnosed based on clinical and family history of the patient along with a characteristic electrocardiogram (Type I ECG): a cave-shaped ST segment elevation above 0.2 mV in right precordial leads (referred to as type I ECG). However, the ECG pattern of BrS patients is dynamical, and thus there is a 25% chance of recording a type I ECG from a BrS patient, and so current ECG diagnosis lacks sensitivity. BrS patients present special ECG characteristics, even in absence of a type I ECG. The objective of this thesis was to determine which spatio-temporal characteristics of the ECGs of BrS patients may allow to increase the sensitivity of the ECG-based diagnosis. We have found that the duration and orientation of terminal R waves on the ECG allow to discriminate between non-type I BrS vs. non BrS subjects with a sensitivity of 75%, increasing in 50% the sensitivity of current ECG criteria

[ES] El síndrome de Brugada (SBr) causa muerte súbita en pacientes con corazones estructuralmente normales. El SBr se diagnostica en base a los antecedentes clínicos y familiares del paciente junto con un electrocardiograma característico (ECG tipo I): una elevación del segmento ST en forma de cueva por encima de 0,2 mV en las derivaciones precordiales derechas (se refiere al él como ECG tipo I). Sin embargo, el patrón del ECG de los pacientes con SBr es dinámico, y por lo tanto hay una probabilidad del 25% de registrar un ECG tipo I en un paciente con SBr, por lo tanto el diagnóstico actual mediante el ECG carece de sensibilidad. Los pacientes con SBr presentan características especiales en el ECG, incluso en ausencia de un ECG tipo I. El objetivo de esta tesis ha sido determinar qué características espacio-temporales de los ECG de pacientes con SBr pueden permitir un aumento en la sensibilidad del diagnóstico basado en el ECG. Hemos encontrado que la duración y la orientación de las ondas R' en el ECG permiten discriminar entre los pacientes con SBr sin un ECG de tipo I vs sujetos sin SBr con una sensibilidad del 75%, aumentando en 50% la sensibilidad de los actuales criterios electrocardiográficos., [EN] Brugada syndrome (BrS) causes sudden death in patients with structurally normal hearts. BrS is diagnosed based on clinical and family history of the patient along with a characteristic electrocardiogram (Type I ECG): a cave-shaped ST segment elevation above 0.2 mV in right precordial leads (referred to as type I ECG). However, the ECG pattern of BrS patients is dynamical, and thus there is a 25% chance of recording a type I ECG from a BrS patient, and so current ECG diagnosis lacks sensitivity. BrS patients present special ECG characteristics, even in absence of a type I ECG. The objective of this thesis was to determine which spatio-temporal characteristics of the ECGs of BrS patients may allow to increase the sensitivity of the ECG-based diagnosis. We have found that the duration and orientation of terminal R waves on the ECG allow to discriminate between non-type I BrS vs. non BrS subjects with a sensitivity of 75%, increasing in 50% the sensitivity of current ECG criteria

About one third of all acute coronary events is ST elevated myocardial infarction (MI). Prehospital mortality of patients in Europe and Ukraine is 30–50 %, in-hospital — 8–13 %. Therefore, the problem of MI diagnosis is of current interest. Although we have highly informative methods such as myocardial perfusion scintigraphy, emission computed tomography and magnetic resonance tomography, echocardiography, ultrasound and contrast coronary angiography, in fact the only method of instrumental diagnostics in practice is medical electrocardiogram (ECG). However, atypical pain or no changes on the standard ECG can complicate the diagnosis of acute coronary disease. Especially when you consider that markers of myocardial necrosis are not absolutely specific and sensitive, depending on the disease and comorbidity. First of all it concerns the posterior basal MI when ECG can show only indirect signs of myocardial damage. Therefore, the introduction of a new noninvasive method of electromotive forces of the heart research on cardiodiagnostic polygraph MTM-SCM allows not only to clarify the localization of necrobiotic processes in the myocardium, but also to obtain additional information about the electrical activity of the heart, including the «dead» zone, which is especially important in «mute» ECG It should be noted that foreign researchers study electrical instability of myocardium in MI using vector analysis, but electrophysiological features of this localization are not reflected in the available literature.The purpose is to identify vectorcardiographic (VCG) signs of acute MI with posterior-inferior Q wave with the spread to the posterior basal part of the left ventricle (LV) and to define its main prognostic factors. Materials and Methods. The work includes 17 patients with primary posterior-inferior MI and 14 patients with primary massive posterior LV MI with the average age of 69 ± 3 and 66 ± 3 years. Patients were hospitalized in the first 24 hours of onset. Instru, Цель работы — выявить векторкардиографические (ВКГ) особенности острого инфаркта миокарда (ИМ) с зубцом Q задненижней локализации с распространением на заднебазальную область левого желудочка (ЛЖ) и определить главные прогностические факторы его течения. В работу включены 17 больных с первичным ИМ задненижней локализации и 14 больных с первичным обширным ИМ задней стенки ЛЖ. Больные госпитализированы в первые 24 часа от начала заболевания. Инструментальное исследование включало электрокардиограмму в стандартных отведениях, V7–9, dorsalis по Небу, V3R и V4R и ВКГ в пяти проекциях по Акулиничеву на кардиодиагностическом многофункциональном комплексе МТМ-СКМ. При анализе ВКГ-показателей при остром обширном ИМ определяется выраженное замедление внутрижелудочковой и внутрипредсердной проводимости с нарушением процессов реполяризации в зоне повреждения ЛЖ с вовлечением задней области обоих предсердий. Применение адекватного метода прогнозирования исходов повреждения заднебазального отдела ЛЖ, а именно алгоритма Data Mining «Дерево решений», позволило выявить значимый фактор вероятной смерти — скорость распространения возбуждения по петле Т в конечной части в ВА5. При снижении этого показателя меньше чем 2,525 mV/с с точностью 93 % прогнозируется летальный исход. Если скорость будет выше указанной или приравниваться к ней, прогноз будет благоприятным., Мета роботи — виявити векторкардіографічні (ВКГ) ознаки гострого інфаркту міокарда (ІМ) із зубцем Q задньонижньої локалізації з поширенням на задньобазальну ділянку лівого шлуночка (ЛШ) та встановити головні прогностичні чинники його перебігу. У роботу включені 17 хворих із первинним ІМ задньонижньої локалізації та 14 хворих із первинним поширеним ІМ задньої стінки ЛШ. Хворі госпіталізовані в перші 24 години від початку захворювання. Інструментальне дослідження включало електрокардіограму в стандартних відвіденнях, V7–9, dorsalis за Небом, V3R і V4R та ВКГ у п’яти проекціях за Акулінічевим на кардіодіагностичному багатофункціональному комплексі ­МТМ-СКМ. При аналізі ­ВКГ-показників при гострому поширеному ІМ визначається виражене сповільнення внутрішньошлуночкової та внутрішньопередсердної провідності з порушенням процесів реполяризації в зоні пошкодження ЛШ із залученням задньої ділянки обох передсердь. Застосування адекватного методу прогнозування наслідків ушкодження задньобазального відділу ЛШ, а саме алгоритму Data Mining «Дерева рішень», дозволило виявити значущий чинник імовірної смерті — швидкість поширення збудження петлею Т у кінцевій частині у ВА5. За зниженням цього показника менше ніж 2,525 mV/с із точністю 93 % прогнозується летальний кінець. Якщо швидкість буде вищою від зазначеної або дорівнювати їй, прогноз буде сприятливим.

Conventional 12-lead electrocardiographic signals must be subjected to noise removal and data reduction schemes before pattern recognition techniques may be applied for automated diagnosis. A batch-processing and an adaptive recursive filtering scheme are developed and studied experimentally. A physical model for the generation of cardiographic signals is exploited to study the relationship of the standard electrocardiogram (ECG), to the three-channel vectorcardiogram (VCG) using the Frank-Orthogonal-lead system. A linear time-invariant relationship between the ECG and the VCT is postulated on the basis of the physical model. Estimation of the VCG from the ECG, based on the various models, is studied experimentally over an ensemble of nine patients. The results indicate that on an individual basis the models give quite good results, but that a single satisfactory fixed model valid for the whole ensemble of patients is not specifiable. Factor Analysis and the Karhunen-loeve expansion are then considered as alternatives to preliminary data reduction of the ECG by estimation of the VCG. A signal processor that can be easily implemented on a minicomputer and that reduces the full set of 12-time signals (the ECG) to a set of a few constant parameters (the pattern vector) is determined.

Srdeční poruchy, jejichž příkladem je ischemie myokardu, infarkt, hypertrofie levé komory a myokarditida, jsou v experimentální kardiologii obvykle studovány na modelu izolovaného srdce. Kritéria pro detekci srdečních poruch však nejsou pro zvířecí modely standardizována, což komplikuje srovnání a interpretaci výsledků různých experimentálních studií. Obzvlášť složitá situace nastává při současném výskytu několika patologických jevů, jejichž vzájemná součinnost komplikuje rozpoznání jejich individuálních účinků. Korektní posouzení stavu srdce vyžaduje také zohlednění mnoha faktorů spojených s akvizicí dat. Tato práce je věnována kvantitativnímu hodnocení elektrofyziologických změn způsobených globální ischemií myokardu. Vliv ischemie byl hodnocen pro fyziologická srdce a srdce se zvětšenou levou komorou a dále pro srdce nabarvená napěťově-citlivým barvivem di-4-ANEPPS. Přestože jsou oba fenomény často zastoupeny v animálních studiích, nebyl dosud popsán jejich vliv na manifestaci ischemie v elektrogramech (EG), ani nebyl kvantifikován jejich vliv na přesnost detekčních algoritmů pro identifikaci ischemie. Práce shrnuje kvantitativní změny srdeční funkce vyvolané ischemií (v normálních podmínkách, při hypertrofii levé komory, a při administraci barviva) založené na hodnocení EG a VKG parametrů. Dále práce obsahuje rozbor důležitých aspektů akvizice záznamů, jako je umístění snímacích elektrod, způsob výpočtu deskriptorů z EG a VKG (s použitím výsledků manuálního rozměření záznamů, nebo bez něj) a identifikace okamžiku vývoje ischemie v preparátu. Nedílnou součást práce tvoří návrh, realizace a ověření metod pro automatickou detekci ischemie v experimentálních záznamech. Výsledky práce dokazují, že dosažení opakovatelných a věrohodných výsledků je podmíněno zohledněním všech výše uvedených faktorů souvisejících jak se stavem srdce, tak s metodikou záznamu a analýzy dat., Isolated heart is widely used in experimental cardiology to study myocardial ischemia and infarct, left ventricular hypertrophy, myocarditis, etc. Nevertheless, the standardized criteria for assessment of above disorders in animal models are missing that complicates interpretation of the results obtained in such studies. It is of special importance, if several pathologies are presented simultaneously, when possible co-effects cannot be simply identified and analysed. Besides the condition of the heart, there are many other factors playing important role in data acquisition and analysis. In this work, electrophysiological effects of increased left ventricular mass (intrinsic factor) and voltage-sensitive dye di-4-ANEPPS (external factor) are evaluated on rabbit isolated hearts under non-ischemic and ischemic condition. Although both phenomena are quite frequent in animal studies, their effects on ischemia manifestations and electrogram-based ischemia detection accuracy have not been quantitatively described yet. Results of quantification of ischemia-induced changes in heart function (under normal conditions, increased LV or dye administration) by analysis of various EG and VCG parameters are summarized. Such important aspects as recording electrodes placement, method of parameters calculation (using or without outcomes of manual EG delineation) and definition of the beginning of ‘true’ ischemic injury in preparation (methodological factors) are also addressed. Along with it, different tools for automatic detection of ischemia in data are presented. According to the results of statistical analysis of parameters and testing the detectors on different data, all above mentioned phenomena (both heart-related and methodological) should be taken into account to ensure successful study of the heart electrical activity.

Srdeční poruchy, jejichž příkladem je ischemie myokardu, infarkt, hypertrofie levé komory a myokarditida, jsou v experimentální kardiologii obvykle studovány na modelu izolovaného srdce. Kritéria pro detekci srdečních poruch však nejsou pro zvířecí modely standardizována, což komplikuje srovnání a interpretaci výsledků různých experimentálních studií. Obzvlášť složitá situace nastává při současném výskytu několika patologických jevů, jejichž vzájemná součinnost komplikuje rozpoznání jejich individuálních účinků. Korektní posouzení stavu srdce vyžaduje také zohlednění mnoha faktorů spojených s akvizicí dat. Tato práce je věnována kvantitativnímu hodnocení elektrofyziologických změn způsobených globální ischemií myokardu. Vliv ischemie byl hodnocen pro fyziologická srdce a srdce se zvětšenou levou komorou a dále pro srdce nabarvená napěťově-citlivým barvivem di-4-ANEPPS. Přestože jsou oba fenomény často zastoupeny v animálních studiích, nebyl dosud popsán jejich vliv na manifestaci ischemie v elektrogramech (EG), ani nebyl kvantifikován jejich vliv na přesnost detekčních algoritmů pro identifikaci ischemie. Práce shrnuje kvantitativní změny srdeční funkce vyvolané ischemií (v normálních podmínkách, při hypertrofii levé komory, a při administraci barviva) založené na hodnocení EG a VKG parametrů. Dále práce obsahuje rozbor důležitých aspektů akvizice záznamů, jako je umístění snímacích elektrod, způsob výpočtu deskriptorů z EG a VKG (s použitím výsledků manuálního rozměření záznamů, nebo bez něj) a identifikace okamžiku vývoje ischemie v preparátu. Nedílnou součást práce tvoří návrh, realizace a ověření metod pro automatickou detekci ischemie v experimentálních záznamech. Výsledky práce dokazují, že dosažení opakovatelných a věrohodných výsledků je podmíněno zohledněním všech výše uvedených faktorů souvisejících jak se stavem srdce, tak s metodikou záznamu a analýzy dat., Isolated heart is widely used in experimental cardiology to study myocardial ischemia and infarct, left ventricular hypertrophy, myocarditis, etc. Nevertheless, the standardized criteria for assessment of above disorders in animal models are missing that complicates interpretation of the results obtained in such studies. It is of special importance, if several pathologies are presented simultaneously, when possible co-effects cannot be simply identified and analysed. Besides the condition of the heart, there are many other factors playing important role in data acquisition and analysis. In this work, electrophysiological effects of increased left ventricular mass (intrinsic factor) and voltage-sensitive dye di-4-ANEPPS (external factor) are evaluated on rabbit isolated hearts under non-ischemic and ischemic condition. Although both phenomena are quite frequent in animal studies, their effects on ischemia manifestations and electrogram-based ischemia detection accuracy have not been quantitatively described yet. Results of quantification of ischemia-induced changes in heart function (under normal conditions, increased LV or dye administration) by analysis of various EG and VCG parameters are summarized. Such important aspects as recording electrodes placement, method of parameters calculation (using or without outcomes of manual EG delineation) and definition of the beginning of ‘true’ ischemic injury in preparation (methodological factors) are also addressed. Along with it, different tools for automatic detection of ischemia in data are presented. According to the results of statistical analysis of parameters and testing the detectors on different data, all above mentioned phenomena (both heart-related and methodological) should be taken into account to ensure successful study of the heart electrical activity.

Srdeční poruchy, jejichž příkladem je ischemie myokardu, infarkt, hypertrofie levé komory a myokarditida, jsou v experimentální kardiologii obvykle studovány na modelu izolovaného srdce. Kritéria pro detekci srdečních poruch však nejsou pro zvířecí modely standardizována, což komplikuje srovnání a interpretaci výsledků různých experimentálních studií. Obzvlášť složitá situace nastává při současném výskytu několika patologických jevů, jejichž vzájemná součinnost komplikuje rozpoznání jejich individuálních účinků. Korektní posouzení stavu srdce vyžaduje také zohlednění mnoha faktorů spojených s akvizicí dat. Tato práce je věnována kvantitativnímu hodnocení elektrofyziologických změn způsobených globální ischemií myokardu. Vliv ischemie byl hodnocen pro fyziologická srdce a srdce se zvětšenou levou komorou a dále pro srdce nabarvená napěťově-citlivým barvivem di-4-ANEPPS. Přestože jsou oba fenomény často zastoupeny v animálních studiích, nebyl dosud popsán jejich vliv na manifestaci ischemie v elektrogramech (EG), ani nebyl kvantifikován jejich vliv na přesnost detekčních algoritmů pro identifikaci ischemie. Práce shrnuje kvantitativní změny srdeční funkce vyvolané ischemií (v normálních podmínkách, při hypertrofii levé komory, a při administraci barviva) založené na hodnocení EG a VKG parametrů. Dále práce obsahuje rozbor důležitých aspektů akvizice záznamů, jako je umístění snímacích elektrod, způsob výpočtu deskriptorů z EG a VKG (s použitím výsledků manuálního rozměření záznamů, nebo bez něj) a identifikace okamžiku vývoje ischemie v preparátu. Nedílnou součást práce tvoří návrh, realizace a ověření metod pro automatickou detekci ischemie v experimentálních záznamech. Výsledky práce dokazují, že dosažení opakovatelných a věrohodných výsledků je podmíněno zohledněním všech výše uvedených faktorů souvisejících jak se stavem srdce, tak s metodikou záznamu a analýzy dat., Isolated heart is widely used in experimental cardiology to study myocardial ischemia and infarct, left ventricular hypertrophy, myocarditis, etc. Nevertheless, the standardized criteria for assessment of above disorders in animal models are missing that complicates interpretation of the results obtained in such studies. It is of special importance, if several pathologies are presented simultaneously, when possible co-effects cannot be simply identified and analysed. Besides the condition of the heart, there are many other factors playing important role in data acquisition and analysis. In this work, electrophysiological effects of increased left ventricular mass (intrinsic factor) and voltage-sensitive dye di-4-ANEPPS (external factor) are evaluated on rabbit isolated hearts under non-ischemic and ischemic condition. Although both phenomena are quite frequent in animal studies, their effects on ischemia manifestations and electrogram-based ischemia detection accuracy have not been quantitatively described yet. Results of quantification of ischemia-induced changes in heart function (under normal conditions, increased LV or dye administration) by analysis of various EG and VCG parameters are summarized. Such important aspects as recording electrodes placement, method of parameters calculation (using or without outcomes of manual EG delineation) and definition of the beginning of ‘true’ ischemic injury in preparation (methodological factors) are also addressed. Along with it, different tools for automatic detection of ischemia in data are presented. According to the results of statistical analysis of parameters and testing the detectors on different data, all above mentioned phenomena (both heart-related and methodological) should be taken into account to ensure successful study of the heart electrical activity.