Ventricular Activity
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2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Wenzhi Zhang ◽  
Runchuan Li ◽  
Shengya Shen ◽  
Jinliang Yao ◽  
Yan Peng ◽  
...  

Myocardial infarction (MI) is one of the most common cardiovascular diseases threatening human life. In order to accurately distinguish myocardial infarction and have a good interpretability, the classification method that combines rule features and ventricular activity features is proposed in this paper. Specifically, according to the clinical diagnosis rule and the pathological changes of myocardial infarction on the electrocardiogram, the local information extracted from the Q wave, ST segment, and T wave is computed as the rule feature. All samples of the QT segment are extracted as ventricular activity features. Then, in order to reduce the computational complexity of the ventricular activity features, the effects of Discrete Wavelet Transform (DWT), Principal Component Analysis (PCA), and Locality Preserving Projections (LPP) on the extracted ventricular activity features are compared. Combining rule features and ventricular activity features, all the 12 leads features are fused as the ultimate feature vector. Finally, eXtreme Gradient Boosting (XGBoost) is used to identify myocardial infarction, and the overall accuracy rate of 99.86% is obtained on the Physikalisch-Technische Bundesanstalt (PTB) database. This method has a good medical diagnosis basis while improving the accuracy, which is very important for clinical decision-making.


2021 ◽  
Author(s):  
Karl Magtibay ◽  
Stéphane Massé ◽  
Ahmed Niri ◽  
Robert D. Anderson ◽  
Ram B. Kumar ◽  
...  

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5302
Author(s):  
Yaru Yue ◽  
Chengdong Chen ◽  
Pengkun Liu ◽  
Ying Xing ◽  
Xiaoguang Zhou

Atrial fibrillation (AF) is the most frequently encountered cardiac arrhythmia and is often associated with other cardiovascular and cerebrovascular diseases, such as ischemic heart disease, chronic heart failure, and stroke. Automatic detection of AF by analyzing electrocardiogram (ECG) signals has an important application value. Using the contaminated and actual ECG signals, it is not enough to only analyze the atrial activity of disappeared P wave and appeared F wave in the TQ segment. Moreover, the best analysis method is to combine nonlinear features analyzing ventricular activity based on the detection of R peak. In this paper, to utilize the information of the P-QRS-T waveform generated by atrial and ventricular activity, frequency slice wavelet transform (FSWT) is adopted to conduct time-frequency analysis on short-term ECG segments from the MIT-BIH Atrial Fibrillation Database. The two-dimensional time-frequency matrices are obtained. Furthermore, an average sliding window is used to convert the two-dimensional time-frequency matrices to the one-dimensional feature vectors, which are classified using five machine learning (ML) techniques. The experimental results show that the classification performance of the Gaussian-kernel support vector machine (GKSVM) based on the Bayesian optimizer is better. The accuracy of the training set and validation set are 100% and 93.4%. The accuracy, sensitivity, and specificity of the test set without training are 98.15%, 96.43%, and 100%, respectively. Compared with previous research results, our proposed FSWT-GKSVM model shows stability and robustness, and it could achieve the purpose of automatic detection of AF.


Heart Rhythm ◽  
2021 ◽  
Vol 18 (8) ◽  
pp. S467
Author(s):  
Karl Magtibay ◽  
Stephane Masse ◽  
Ahmed Niri ◽  
D. Curtis Deno ◽  
Kumaraswamy Nanthakumar

Heart Rhythm ◽  
2021 ◽  
Vol 18 (8) ◽  
pp. S77
Author(s):  
Karl Magtibay ◽  
Stephane Masse ◽  
Ahmed Niri ◽  
D. Curtis Deno ◽  
Kumaraswamy Nanthakumar

Author(s):  
Takashi Nakashima ◽  
Ghassen Cheniti ◽  
Takamitsu Takagi ◽  
Konstantinos Vlachos ◽  
Cyril Goujeau ◽  
...  

2020 ◽  
Vol 27 ◽  
pp. 22-27
Author(s):  
K. A. Simonova ◽  
E. N. Mikhaylov ◽  
R. B. Tatarskiy ◽  
A. V. Kamenev ◽  
D. V. Panin ◽  
...  

Introduction. Radiofrequency ablation (RFA) is an established treatment of post-myocardial infarction ventricular tachycardia (VT). Endocardial VT ablation can be insufficient for VT termination when the scar is intramural/epicardial.Purpose: to assess the extent of epicardial electrophysiological VT substrate in patients with remote myocardial infarction.Materials and methods. Thirteen patients with sustained postinfarction VT, who signed an informed consent, were included into the study. All patients underwent full clinical evaluation. Electroanatomical voltage bi- and unipolar mapping of endocardial and epicardial surfaces was performed. Maps were evaluated for the presence of low-voltage areas and local abnormal ventricular activity (LAVA). RFA was performed at LAVA sites. The end-point of the procedure was scar LAVA abolition and VT noninducibility (procedure success). VT recurrence was detected using an implantable cardioverter-defibrillator and/or ECG monitoring.Results. Epicardial access was successful in 12 patients. Epicardial access was performed at a first procedure in 7 patients, 4 patients had a history of previous endocardial ablation. Epicardial LAVA sites were detected in 9 patients. Endocardial and epicardial arrhythmogenic substrate localization coincided in 8 patients. One patient had only epicardial scar, 1 patient had only septal endocardial scar. In one patient LAVA sites had different localizations on epicardial and endocardial maps. Acute ablation success was noted in 12 patients.Conclusion. In our patient group transmural scar and epicardial electrophysiological arrhythmogenic substrate was detected in 82% of cases. Isolated endocardial ablation may be unsuccessful, in such cases epicardial mapping and ablation might be useful.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shuichi Hiroyama ◽  
Takemi Rokugawa ◽  
Miwa Ito ◽  
Hitoshi Iimori ◽  
Ippei Morita ◽  
...  

Abstract Background Integrin αvβ3, which are expressed by activated hepatic stellate cells in non-alcoholic steatohepatitis (NASH), play an important role in the fibrosis. Recently, we reported that an RGD peptide positron emission tomography (PET) probe is useful as a predictor of hepatic fibrosis. Kinetic analysis of the RGD PET probe has been performed in tumours, but not in hepatic fibrosis. Therefore, we aimed to quantify hepatic integrin αvβ3 in a model of NASH by kinetic analysis using 18F-FPP-RGD2, an integrin αvβ3 PET probe. Methods 18F-FPP-RGD2 PET/CT scans were performed in control and NASH rats. Tissue kinetic analyses were performed using a one-tissue, two-compartment (1T2C) and a two-tissue, three-compartment (2T3C) model using an image-derived input function (IDIF) for the left ventricle. We then conducted correlation analysis between standard uptake values (SUVs) or volume of distribution (VT), evaluated using compartment kinetic analysis and integrin αv or β3 protein expression. Results Biochemical and histological evaluation confirmed the development of NASH rats. Integrin αvβ3 protein expression and hepatic SUV were higher in NASH- than normal rats. The hepatic activity of 18F-FPP-RGD2 peaked rapidly after administration and then gradually decreased, whereas left ventricular activity rapidly disappeared. The 2T3C model was found to be preferable for 18F-FPP-RGD2 kinetic analysis in the liver. The VT (IDIF) for 18F-FPP-RGD2, calculated using the 2T3C model, was significantly higher in NASH- than normal rats and correlated strongly with hepatic integrin αv and β3 protein expression. The strengths of these correlations were similar to those between SUV60–90 min and hepatic integrin αv or β3 protein expression. Conclusions We have demonstrated that the VT (IDIF) of 18F-FPP-RGD2, calculated using kinetic modelling, positively correlates with integrin αv and β3 protein in the liver of NASH rats. These findings suggest that hepatic VT (IDIF) provides a quantitative assessment of integrin αvβ3 protein in liver.


2020 ◽  
Author(s):  
Shuichi Hiroyama ◽  
Takemi Rokugawa ◽  
Miwa Ito ◽  
Hitoshi Iimori ◽  
Ippei Morita ◽  
...  

Abstract Background Integrin αvβ3, which are expressed by activated hepatic stellate cells in non-alcoholic steatohepatitis (NASH), play an important role in the fibrosis. Recently, we reported that an RGD peptide positron emission tomography (PET) probe is useful as a predictor of hepatic fibrosis. Kinetic analysis of the RGD PET probe has been performed in tumours, but not in hepatic fibrosis. Therefore, we aimed to quantify hepatic integrin αvβ3 in a model of NASH by kinetic analysis using 18F-FPP-RGD2, an integrin αvβ3 PET probe.Methods 18F-FPP-RGD2 PET/CT scans were performed in control and NASH rats. Tissue kinetic analyses were performed using a one-tissue, two-compartment (1T2C) and a two-tissue, three-compartment (2T3C) model using an image-derived input function (IDIF) for the left ventricle. We then conducted correlation analysis between standard uptake values (SUVs) or volume of distribution (VT), evaluated using compartment kinetic analysis, and integrin αv or β3 protein expression.Results Biochemical and histological evaluation confirmed the development of NASH rats. Integrin αvβ3 protein expression and hepatic SUV were higher in NASH- than normal rats. The hepatic activity of 18F-FPP-RGD2 peaked rapidly after administration and then gradually decreased, whereas left ventricular activity rapidly disappeared. The 2T3C model was found to be preferable for 18F-FPP-RGD2 kinetic analysis in the liver. The VT (IDIF) for 18F-FPP-RGD2, calculated using the 2T3C model, was significantly higher in NASH- than normal rats and correlated strongly with hepatic integrin αv and β3 protein expression. The strengths of these correlations were similar to those between SUV60–90 min and hepatic integrin αv or β3 protein expression.Conclusions We have demonstrated that the VT (IDIF) of 18F-FPP-RGD2, calculated using kinetic modelling, positively correlates with integrin αv and β3 protein in the liver of NASH rats. These findings suggest that hepatic VT (IDIF) provides a quantitative assessment of integrin αvβ3 protein in liver.


2020 ◽  
Vol 16 ◽  
Author(s):  
Andrés Ricardo Pérez-Riera ◽  
Raimundo Barbosa-Barros ◽  
Rodrigo Daminello-Raimundo ◽  
Luiz Carlos de Abreu ◽  
Kjell Nikus

: Until the mid-1980s, it was believed that the vectorcardiogram (VCG) presented a greater specificity, sensitivity and accuracy in comparison to the 12-lead electrocardiogram (ECG), in the cardiology diagnosis. Currently, the VCG still is superior to the ECG in specific situations, such as in the evaluation of myocardial infarctions when associated with intraventricular conduction disturbances, in the identification and location of accessory pathways in ventricular preexcitation, in the differential diagnosis of patterns varying from normal of electrical axis deviation, in the evaluation of particular aspects of Brugada syndrome, Brugada phenocopies, concealed form of arrhythmogenic right ventricular cardiomyopathy and zonal or fascicular blocks of the right bundle branch on right ventricular free wall .VCG allows us to analyze the presence of left septal fascicular block more accurately than ECG and in the diagnosis of the interatrial blocks and severity of some chambers enlargements. The three-dimensional spatial orientation of both the atrial and the ventricular activity provides a far more complete observation tool than the linear ECG. We believe that the ECG/VCG binomial simultaneously obtained by the technique called electro-vectorcardiography (ECG/VCG) brought a significant gain for the differential diagnosis of several pathologies. Finally, in the field of education and research, VCG provided a better and more rational tridimensional insight into the electrical phenomena that occurs spatially, and represented an important impact on the progress of electrocardiography.


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