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Computers in Cardiology 1997最新文献

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Neurocardiologic and fitness changes in marathon skaters during interruption of training after their last competitive contest of the winter season 马拉松滑冰运动员在冬季最后一场竞技比赛后训练中断期间的神经心脏学和健康变化
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.648022
J. Frederiks, C. A. Swenne, A. Maan, M. VanRooyen, P. Schiereck, W. Mosterd, B. J. Tenvoorde, A. Bruschke
{"title":"Neurocardiologic and fitness changes in marathon skaters during interruption of training after their last competitive contest of the winter season","authors":"J. Frederiks, C. A. Swenne, A. Maan, M. VanRooyen, P. Schiereck, W. Mosterd, B. J. Tenvoorde, A. Bruschke","doi":"10.1109/CIC.1997.648022","DOIUrl":"https://doi.org/10.1109/CIC.1997.648022","url":null,"abstract":"The authors studied nine male Dutch top marathon skaters during a one-month interruption of their training schedules after their last contest in the winter. Before and after this period a maximal exercise test was done, and at days 0, 4, 7, 14 and 28 neurocardiologic measurement sessions-heart rate (HR) and noninvasive baroreflex sensitivity (BRS), recumbent and tilt-were done. Interruption of training resulted in a significant and relevant decrease in the maximal oxygen uptake (from 65.7/spl plusmn/5.8 to 61.6/spl plusmn/4.7 ml O/sub 2/.kg/sup -1/. min/sup -1/; P=0.03), most likely to be associated with decreased competitive possibilities. A modest increase in resting heart rate (from 54.6/spl plusmn/7.2 to 58.8/spl plusmn/7.5 bpm) became not significant. Heart rate during 60/spl deg/ tilt increased considerably (from 70.3/spl plusmn/6.1 to 80.1/spl plusmn/9.1 bpm; P=0.01), possibly due to a decrease in blood volume and an increase in cardiopulmonary baroreflex gain. Baroreflex sensitivity decreased in the recumbent (from 13.3/spl plusmn/5.4 to 9.8/spl plusmn/3.8 ms/mmHg, P=0.04), but not in the 60/spl deg/ tilt position (from 6.7/spl plusmn/2.0 to 6.0/spl plusmn/2.5 ms/mmHg). The meaning of these neurocardiologic changes for athletic performance is unclear. The authors' data show that detrimental changes in fitness, and neurocardiologic changes were measurable after a month of interruption of training, and will probably also be demonstrable in a larger group after 14 days.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128210759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Graphical representation of heart sounds and murmurs 心音和杂音的图形表示
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.647840
Tovar-Corona, JN Tony
{"title":"Graphical representation of heart sounds and murmurs","authors":"Tovar-Corona, JN Tony","doi":"10.1109/CIC.1997.647840","DOIUrl":"https://doi.org/10.1109/CIC.1997.647840","url":null,"abstract":"Presents a new method to represent heart sounds and murmurs in stylised diagrams. Frequency domain analysis, based on an Auto Regressive modelling, shows its superiority against time domain analysis in the identification of the principle sounds (SI and S2), extra-sounds (S3 and S4) and murmurs. Two separated diagrams give information in the time and frequency domain in order to make a simple representation. The analysis begins by identifying individual cardiac cycles. Then S1, S2, extra-sounds and murmurs are segmented using spectral estimation. Finally the cycle with the loudest murmur is identified to represent two final diagrams showing its shape in time and frequency content.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"339 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122755065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Recurrence plot analysis of the coupling between respiration and cardiovascular variability signals 呼吸和心血管变异性信号耦合的递归图分析
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.647868
F. Censi, G. Calcagnini, S. Cerutti
{"title":"Recurrence plot analysis of the coupling between respiration and cardiovascular variability signals","authors":"F. Censi, G. Calcagnini, S. Cerutti","doi":"10.1109/CIC.1997.647868","DOIUrl":"https://doi.org/10.1109/CIC.1997.647868","url":null,"abstract":"The authors performed a quantitative study of sub-harmonic synchronization and entrainment phenomena between respiration and short-term Heart Rate and Blood Pressure variability signals by the Recurrence Plot Analysis (RPA). Quantification of the recurrence plots has been obtained using descriptors such as Percent Recurrence, Percent Determinism and Entropy of Recurrences. The authors applied RPA to data obtained in control breathing at different frequencies from 10 normal subjects. The breathing frequencies were chosen to elicit interference phenomena between LF and HF frequency components. Unlike the power spectral estimation, RPA seems to be succeeds in detecting entrainment and transient phase locking phenomena; moreover, the recurrence descriptors turn out to be particularly suited for a quantitative evaluation of the different phenomena observed.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122633313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Increased QRS complex dispersion in postinfarction patients: is it clinically important? 心肌梗死后患者QRS复合物弥散度增加:有临床意义吗?
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.648154
M. Sosnowski, Z. Czyz̊, T. Petelenz, T. Slominska-petelenz, J. Leski, M. Tendera
{"title":"Increased QRS complex dispersion in postinfarction patients: is it clinically important?","authors":"M. Sosnowski, Z. Czyz̊, T. Petelenz, T. Slominska-petelenz, J. Leski, M. Tendera","doi":"10.1109/CIC.1997.648154","DOIUrl":"https://doi.org/10.1109/CIC.1997.648154","url":null,"abstract":"The study was designed to analyse what is the dispersion of QRS complex in 10 normal subjects and whether 65 postinfarction patients have abnormal dispersion of QRS complex and what is its clinical meaning. QRS complex and QT interval duration were measured by means of spectrotemporal mapping of high resolution orthogonal ECG (16 bit, 2 kHz). Abnormal values of QRS complex dispersion and of derived parameters and of QT dispersion were defined as greater than mean+2.5 SD values seen in healthy subjects. Increased QRS dispersion and QT dispersion were found in more than half of post-myocardial infarction (MI) patients (52% and 55%, respectively). QRS dispersion was unrelated to the site of MI, Q-wave and left ventricular ejection fraction, but the dispersion of QRS-complex onset and QT dispersion were found useful for distinguishing MI-patients with or without non-sustained ventricular tachycardia. It is concluded that analysis of QRS complex dispersion may become a new index of increased risk of malignant ventricular arrhythmia in postinfarction patients.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"12 23","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120867302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Adaptive Fourier rebinning for SPECT simultaneous transmission/emission protocol (STEP) SPECT同步传输/发射协议(STEP)的自适应傅立叶重构
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.648142
W. Hawkins, S. Miller, P. Maniawski
{"title":"Adaptive Fourier rebinning for SPECT simultaneous transmission/emission protocol (STEP)","authors":"W. Hawkins, S. Miller, P. Maniawski","doi":"10.1109/CIC.1997.648142","DOIUrl":"https://doi.org/10.1109/CIC.1997.648142","url":null,"abstract":"The adaptive Fourier rebinning algorithm (AFR) for SPECT STEP is a reconstruction technique that is similar to PET Fourier rebinning, in that a transfer function (TF) is constructed to connect the 3D Fourier coefficients of the projection sinograms with the 3D Fourier-Bessel coefficients of the object. This method may also be applied to the X-ray transform, and the authors have applied it to the reconstruction of transmission data in STEP as well. They demonstrate the use of this approach with emission and transmission studies from a Picker Prism-2000 STEP. The AFR method compared favorably with MLEM for both transmission and emission reconstruction For transmission reconstruction, AFR produced images that were quantitatively more accurate overall, with a lower noise level. The AFR provides objective, intelligent criteria to determine the amount of regularization to optimally balance noise and resolution in count-deficient studies. There criteria are based on total counts and attenuation. This is especially important to the scanning of large patients, in which attenuation reduces the number of photons available. The emission MLEM reconstructions were much noisier than AFR, and could not reliably detect a cold lesion in the phantom, whereas AFR was able to detect the lesion.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123108581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Different combination techniques in the computation of the QT dispersion index QT离散度指数计算的不同组合技术
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.648139
G. Bortolan, M. Bressan, C. Cavaggion, S. Fusaro
{"title":"Different combination techniques in the computation of the QT dispersion index","authors":"G. Bortolan, M. Bressan, C. Cavaggion, S. Fusaro","doi":"10.1109/CIC.1997.648139","DOIUrl":"https://doi.org/10.1109/CIC.1997.648139","url":null,"abstract":"The implications of three different combination algorithms for the computation of the QT dispersion index are studied and examined. The two most used indices of QT dispersion have been considered: the difference between max and min QT duration and the standard deviation of the QT duration in the 12 leads. In order to investigate on clinical aspects of the QT dispersion, the three proposed algorithm have been evaluated in the ECG-ILSA database considering four different groups: healthy patients, patients with cardiac arrhythmia, with myocardial infarction, and with both pathologies. The results have shown that on one hand the three algorithms produce (statistically significant) different results, and on the other hand the same relation among the four considered groups is preserved.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"538 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123027923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 4
Coherence and transfer function estimation in cardiovascular variability analysis: a comparison between the classical and autoregressive approach 心血管变异性分析中的相干性和传递函数估计:经典和自回归方法的比较
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.647915
R. Maestri, G. Pinna
{"title":"Coherence and transfer function estimation in cardiovascular variability analysis: a comparison between the classical and autoregressive approach","authors":"R. Maestri, G. Pinna","doi":"10.1109/CIC.1997.647915","DOIUrl":"https://doi.org/10.1109/CIC.1997.647915","url":null,"abstract":"The authors compared by a computer simulation the accuracy of the magnitude squared coherence (MSC) function and of the gain and phase spectrum estimated by the Blackman-Tukey (BT) and autoregressive (AR) methods. Two stochastic processes were generated by AR fitting a real systolic pressure signal and a synthetic signal both containing a very low frequency (0.01-0.04 Hz), a low frequency (0.04-0.15 Hz) and a high frequency (0.15-0.45 Hz) component, passed through a linear block with known transfer function and added to a white noise source. The synthetic signal was characterized by narrower spectral peaks in order to stress the resolving power of the estimated functions. For each process 300 realizations at a record length of 3 and 5 min were generated, the corresponding system output computed and the MSC, gain and phase at the 3 spectral components estimated. The error in the estimation of the gain and phase shift was negligible at all frequencies for both AR and BT. In the estimation of the MSC, AR performed better than BT, which showed a systematic negative bias and a lower spectral resolution.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127861284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Differentiation of supraventricular and ventricular arrhythmias based on morphological analysis of ICD stored electrograms 基于ICD存储电图形态学分析的室上性和室性心律失常鉴别
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.647877
J. Millet, J. Lopez, R. Ruiz, R. García, M. Pérez
{"title":"Differentiation of supraventricular and ventricular arrhythmias based on morphological analysis of ICD stored electrograms","authors":"J. Millet, J. Lopez, R. Ruiz, R. García, M. Pérez","doi":"10.1109/CIC.1997.647877","DOIUrl":"https://doi.org/10.1109/CIC.1997.647877","url":null,"abstract":"Implantable cardioverter defibrillators (ICD) must discriminate between normal sinus rhythm and abnormal arrhythmias, but they must also confront the problem of identifying different arrhythmias such as ventricular tachycardias (VT), ventricular fibrillation (VF) and supraventricular tachycardias (SVT). Rate is yet the main used parameter to distinguish a rhythm from another one but it is often nor successful. The authors propose an algorithm based on the electrogram morphology to discriminate among these rhythms. It uses two different coefficients calculated with CWA, BAM, NAD, DAM and ADIOS with two templates. The evaluation of the algorithm was performed on electrograms (EGM) saved by ICDs during clinical episodes that fulfilled programmed rate criteria. The authors studied from a total of 31 patients with 36 different VTs, 33 VFs and 9 different SVTs.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115894179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Segmentation of left ventricle myocardium in MRI using endocardium layer expansion model 心内膜层扩张模型在MRI上分割左心室心肌
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.647850
S. Furuie, M. Rebelo, M. A. Gutierrez, C. P. Melo
{"title":"Segmentation of left ventricle myocardium in MRI using endocardium layer expansion model","authors":"S. Furuie, M. Rebelo, M. A. Gutierrez, C. P. Melo","doi":"10.1109/CIC.1997.647850","DOIUrl":"https://doi.org/10.1109/CIC.1997.647850","url":null,"abstract":"We present a volumetric approach for segmentation of left ventricle (LV) myocardium in MRI based on fuzzy connectedness and incorporation of voxel with minimum cost. It is a two-step technique: first, segmentation of LV cavity and then expansion of muscle layers keeping roughly the endocardium morphology. The LV cavity is extracted applying competitive fuzzy connectedness between cavity and myocardium. A small region sample of each object is provided by the user to characterize their membership function that is based on likelihood. From the endocardium surface, the connected voxels with minimum insertion cost and below a calculated threshold are incorporated in an orderly fashion. The cost function encompasses local gradient, local texture and shape.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"221 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115990858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Evaluation of respiratory influences on left ventricular function by means of echocardiographic approach 超声心动图法评价呼吸对左心室功能的影响
Computers in Cardiology 1997 Pub Date : 1997-09-07 DOI: 10.1109/CIC.1997.647918
A. Porta, G. Baselli, M. Turiel, C. Crema, L. D. Dalla Vecchia, D. Lucini, E. Caiani, A. Malliani, M. Pagani, S. Cerutti
{"title":"Evaluation of respiratory influences on left ventricular function by means of echocardiographic approach","authors":"A. Porta, G. Baselli, M. Turiel, C. Crema, L. D. Dalla Vecchia, D. Lucini, E. Caiani, A. Malliani, M. Pagani, S. Cerutti","doi":"10.1109/CIC.1997.647918","DOIUrl":"https://doi.org/10.1109/CIC.1997.647918","url":null,"abstract":"A procedure to automatically extract the beat-to-beat series of well-known clinical parameters from the left ventricular volume signal obtained by the acoustic quantification technique is validated in normal subjects and chronic heart failure patients (NYHA class II-III). The end systolic and diastolic volume, the contribution of the atrial contraction to the ventricular filling and the ejection fraction provide a vivid distinction between normal and pathological subjects. However a large amount of variability at the respiratory frequency is observed. The respiratory-related variability of the left ventricular volume parameters could be related to the capability of the heart to adapt to changes of the venous return and, therefore, could be used as an index of the cardiac mechanical efficiency.","PeriodicalId":228649,"journal":{"name":"Computers in Cardiology 1997","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114751788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
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