Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166851
P. Marcheschi, M. Lombardi, A. Mazzarisi, R. Testa, A. Pingitore, A. Benassi, P. Marraccini
Aim of the study was to assess a new method to followup patients with angiographically documented coronary artery disease (CAD), by noninvasive MRI angiography. The method is based on 3D reconstruction of planar cineangiographic images. It is addressed to expand informative content and to extract data from conventional 2D-images, aiming to guide and optimize the use of magnetic resonance for coronary artery visualization. The preliminary tests have shown that it is possible to obtain a fast MRI localization of peripheral coronary segments due to a more precise target volume of scan. This could overcome some limits of MRI examination of coronary tree and expands the use of noninvasive MRI technique in CAD follow-up.
{"title":"3D navigator for localization of peripheral coronary segments by magnetic resonance imaging angiography","authors":"P. Marcheschi, M. Lombardi, A. Mazzarisi, R. Testa, A. Pingitore, A. Benassi, P. Marraccini","doi":"10.1109/CIC.2002.1166851","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166851","url":null,"abstract":"Aim of the study was to assess a new method to followup patients with angiographically documented coronary artery disease (CAD), by noninvasive MRI angiography. The method is based on 3D reconstruction of planar cineangiographic images. It is addressed to expand informative content and to extract data from conventional 2D-images, aiming to guide and optimize the use of magnetic resonance for coronary artery visualization. The preliminary tests have shown that it is possible to obtain a fast MRI localization of peripheral coronary segments due to a more precise target volume of scan. This could overcome some limits of MRI examination of coronary tree and expands the use of noninvasive MRI technique in CAD follow-up.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"629-632"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166851","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62182135","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166853
G. A. L'Abbate, C. Carpeggiani, C. Marchesi, A. L'Abbate
We have developed a system that integrates, through a virtual 3D-dynamic heart model, all the pertinent clinical and instrumental information obtained for patients hospitalized for suspected or documented ischemic heart disease (IHD). In the present study we retrospectively compared the diagnosis formulated by the cardiologist in the discharge record with that automatically provided by the system. Divergences were found in 27% of the 110 patients studied and classified into four types: I) inability of the system to provide the correct diagnosis because of the lack of pertinent diagnostic parameters in the model (3%), a cardiologist's diagnosis which was either II) not supported by objective data (3%), III) in conflict with the available information (10%), or IV) incomplete (11%). An experimental trial has been started in which the cardiologist in charge of the patient uses the automatic system during the diagnostic process and compilation of the discharge report.
{"title":"On-line integration of cardiological data to support medical decision making in patients with ischemic heart disease","authors":"G. A. L'Abbate, C. Carpeggiani, C. Marchesi, A. L'Abbate","doi":"10.1109/CIC.2002.1166853","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166853","url":null,"abstract":"We have developed a system that integrates, through a virtual 3D-dynamic heart model, all the pertinent clinical and instrumental information obtained for patients hospitalized for suspected or documented ischemic heart disease (IHD). In the present study we retrospectively compared the diagnosis formulated by the cardiologist in the discharge record with that automatically provided by the system. Divergences were found in 27% of the 110 patients studied and classified into four types: I) inability of the system to provide the correct diagnosis because of the lack of pertinent diagnostic parameters in the model (3%), a cardiologist's diagnosis which was either II) not supported by objective data (3%), III) in conflict with the available information (10%), or IV) incomplete (11%). An experimental trial has been started in which the cardiologist in charge of the patient uses the automatic system during the diagnostic process and compilation of the discharge report.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"637-640"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166853","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62182188","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166876
S. Patel, R. Malkin
There was a difference in the standard for leakage current in the US and Europe. This difference existed largely because there was very little data on AC stimulation of the heart in situ. In this study, we examine AC stimulation of the intact guinea pig. Nine male guinea pigs were anesthetized with isoflurane, intubated and monitored with the lead II ECG and optical plethysmograph. For AC stimulation, a stainless steel electrode was used The return electrode was applied to the right rear paw. Five seconds of AC stimuli at various frequencies was used The minimum VF threshold in these animals was found to be 558/spl plusmn/314 /spl mu/A at 100 Hz. Frequencies both below (20 Hz: 1584/spl plusmn/753 /spl mu/A) and above (160 Hz: 1355/spl plusmn/1007 pA) were found to be significantly different from 100 Hz (20 Hz: p=0.0017 and 100 Hz: p=0.0085). By contrast the minimum current required to have any effect on the heart only increased with frequency from 10 Hz (119/spl plusmn/53 pA), to 160 Hz (183/spl plusmn/50 pA, p<0. 0001).
{"title":"The response of intact guinea pigs to AC leakage currents","authors":"S. Patel, R. Malkin","doi":"10.1109/CIC.2002.1166876","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166876","url":null,"abstract":"There was a difference in the standard for leakage current in the US and Europe. This difference existed largely because there was very little data on AC stimulation of the heart in situ. In this study, we examine AC stimulation of the intact guinea pig. Nine male guinea pigs were anesthetized with isoflurane, intubated and monitored with the lead II ECG and optical plethysmograph. For AC stimulation, a stainless steel electrode was used The return electrode was applied to the right rear paw. Five seconds of AC stimuli at various frequencies was used The minimum VF threshold in these animals was found to be 558/spl plusmn/314 /spl mu/A at 100 Hz. Frequencies both below (20 Hz: 1584/spl plusmn/753 /spl mu/A) and above (160 Hz: 1355/spl plusmn/1007 pA) were found to be significantly different from 100 Hz (20 Hz: p=0.0017 and 100 Hz: p=0.0085). By contrast the minimum current required to have any effect on the heart only increased with frequency from 10 Hz (119/spl plusmn/53 pA), to 160 Hz (183/spl plusmn/50 pA, p<0. 0001).","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"86 1","pages":"729-731"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166876","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62182755","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166707
G. Nollo, L. Widesott, L. Faes, A. Porta, R. Antolini
The phase spectra obtained by the classical closed loop autoregressive model (2AR) and by an open loop autoregressive model (ARXAR) were compared to shed light on the need of introducing causality in the assessment of the delay between RR and arterial pressure oscillations. The reliability of the two approaches was tested in simulation and real data setting. In simulation, the coupling strength of a bivariate closed loop process was adjusted to obtain a range of working conditions from open to closed loop. In open loop condition, 2AR and ARXAR phases were comparable and in agreement with the imposed delay. In closed loop condition, ARXAR model returned the imposed delays, while 2AR showed an intermediate value of delay. Real data were chosen to represent comparable physiological condition. The use of cross spectrum for calculating the delay from arterial pressure to RR oscillations seems adequate only in particular condition of open-loop relationship as it happens during head up tilt in young healthy subjects.
{"title":"Need of causal analysis for assessing phase relationships in closed loop interacting cardiovascular variability series","authors":"G. Nollo, L. Widesott, L. Faes, A. Porta, R. Antolini","doi":"10.1109/CIC.2002.1166707","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166707","url":null,"abstract":"The phase spectra obtained by the classical closed loop autoregressive model (2AR) and by an open loop autoregressive model (ARXAR) were compared to shed light on the need of introducing causality in the assessment of the delay between RR and arterial pressure oscillations. The reliability of the two approaches was tested in simulation and real data setting. In simulation, the coupling strength of a bivariate closed loop process was adjusted to obtain a range of working conditions from open to closed loop. In open loop condition, 2AR and ARXAR phases were comparable and in agreement with the imposed delay. In closed loop condition, ARXAR model returned the imposed delays, while 2AR showed an intermediate value of delay. Real data were chosen to represent comparable physiological condition. The use of cross spectrum for calculating the delay from arterial pressure to RR oscillations seems adequate only in particular condition of open-loop relationship as it happens during head up tilt in young healthy subjects.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"61-64"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166707","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62179343","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166701
L. Senhadji, Feng Wang, Alfredo I. Hernández, Guy Carrault
P wave detection requires a robust QRS-T cancellation method. Interesting algorithms have been proposed for beat-to-beat QRS-T cancellation. Previous studies have shown that adaptive methods lead to good cancellation of the QRS-T interval which generally guarantees the performance of P wave detection. However, adaptive methods suffer from the nonstationary behavior of ECG signals and particularly beat-to-beat morphology changes of the QRS. We present a new approach for two ECG channel QRS-T cancellation based on the dyadic wavelet transform. The method is insensitive to QRS morphology changes and performs well in the presence of ectopic beats, transient artifacts, baseline drifts and isolated P waves. Our approach allows the P wave to be enhanced better than methods recently proposed.
{"title":"Wavelets extrema representation for QRS-T cancellation and P wave detection","authors":"L. Senhadji, Feng Wang, Alfredo I. Hernández, Guy Carrault","doi":"10.1109/CIC.2002.1166701","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166701","url":null,"abstract":"P wave detection requires a robust QRS-T cancellation method. Interesting algorithms have been proposed for beat-to-beat QRS-T cancellation. Previous studies have shown that adaptive methods lead to good cancellation of the QRS-T interval which generally guarantees the performance of P wave detection. However, adaptive methods suffer from the nonstationary behavior of ECG signals and particularly beat-to-beat morphology changes of the QRS. We present a new approach for two ECG channel QRS-T cancellation based on the dyadic wavelet transform. The method is insensitive to QRS morphology changes and performs well in the presence of ectopic beats, transient artifacts, baseline drifts and isolated P waves. Our approach allows the P wave to be enhanced better than methods recently proposed.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"37-40"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166701","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62179626","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166721
M.L. Brown, J. Christensen, J. Gillberg
The PR Logic dual-chamber defection algorithm discriminates VT/VF from SVT using hierarchical rules based on the pattern and timing of AA, VV, AV, and VA intervals. It cannot always discriminate rapidly-conducted atrial fibrillation(AF) from double tachycardia. Coexisting AF and VT/VF, or SVT with 1:1 antegrade conduction from VT with 1:1 retrograde conduction. This study evaluated a new tachyarrhythmia detection algorithm that supplements analysis of dual-chamber intervals with analysis of ventricular electrogram morphology based on the Wavelet Dynamic Discrimination Algorithm. Combined analysis of dual-chamber intervals and ventricular electrogram morphology reduced inappropriate detection of SVTs by 79% compared to dual chamber intervals alone without compromising sensitivity for detection of VT/VF.
{"title":"Improved discrimination of VT from SVT in dual-chamber ICDs by combined analysis of dual-chamber intervals and ventricular electrogram morphology","authors":"M.L. Brown, J. Christensen, J. Gillberg","doi":"10.1109/CIC.2002.1166721","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166721","url":null,"abstract":"The PR Logic dual-chamber defection algorithm discriminates VT/VF from SVT using hierarchical rules based on the pattern and timing of AA, VV, AV, and VA intervals. It cannot always discriminate rapidly-conducted atrial fibrillation(AF) from double tachycardia. Coexisting AF and VT/VF, or SVT with 1:1 antegrade conduction from VT with 1:1 retrograde conduction. This study evaluated a new tachyarrhythmia detection algorithm that supplements analysis of dual-chamber intervals with analysis of ventricular electrogram morphology based on the Wavelet Dynamic Discrimination Algorithm. Combined analysis of dual-chamber intervals and ventricular electrogram morphology reduced inappropriate detection of SVTs by 79% compared to dual chamber intervals alone without compromising sensitivity for detection of VT/VF.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"117-120"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166721","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62179993","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166766
H. Park, W. Groh, W. Combs, E. Berbari
This study presents several new approaches to analyze the non-invasively recorded His-Purkinje system (HPS) signals from patients with myotonic muscular dystrophy. A high resolution electrocardiogram based on signal averaging to improve the signal-to-noise ratio(SNR) is a well established means to record HPS potentials. These new approaches used methods to temporally and spectrally separate the HPS potentials from the P wave potentials. These included both physiologically based and signal processing based schemes. Separating or shifting the P wave from the HPS potentials using heart rate dependent averaging and the addition of several highpass filtering methods proved somewhat, but not totally successful. In the group of patients with sequential recordings over a period of two years the progression of their muscular dystrophy may also be seen in the heart as well. This may then produce noticeable progressive trends or changes in their HPS waveforms over time. The most noticeable changes found in this study were temporal changes and morphological changes of the HPS activity of these patients over time.
{"title":"Analysis of non-invasively recorded His-Purkinje signals from patients with myotonic muscular dystrophy","authors":"H. Park, W. Groh, W. Combs, E. Berbari","doi":"10.1109/CIC.2002.1166766","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166766","url":null,"abstract":"This study presents several new approaches to analyze the non-invasively recorded His-Purkinje system (HPS) signals from patients with myotonic muscular dystrophy. A high resolution electrocardiogram based on signal averaging to improve the signal-to-noise ratio(SNR) is a well established means to record HPS potentials. These new approaches used methods to temporally and spectrally separate the HPS potentials from the P wave potentials. These included both physiologically based and signal processing based schemes. Separating or shifting the P wave from the HPS potentials using heart rate dependent averaging and the addition of several highpass filtering methods proved somewhat, but not totally successful. In the group of patients with sequential recordings over a period of two years the progression of their muscular dystrophy may also be seen in the heart as well. This may then produce noticeable progressive trends or changes in their HPS waveforms over time. The most noticeable changes found in this study were temporal changes and morphological changes of the HPS activity of these patients over time.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"293-296"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166766","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62180514","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166767
H. Kestler, A. Muller, V. Hombach, J. Wohrle, O. Grebe, G. Palm, M. Moher, F. Schwenker
Two types of measurements are usually performed from high resolution ECG recordings: (a) static parameters derived from the signal-averaged QRS complex and (b) variant markers derived from beat-to-beat recordings. It is known that an increased QRS micro-variability and ventricular late potentials are associated with an increased risk for malignant arrhythmias. However, the diagnostic power of the singular parameters is limited In this study we investigated the diagnostic ability of a decision fusion of both variant and static high-resolution ECG parameters with radial-basis-function (RBF) networks. Continuous and signal-averaged ECGs were recorded from 51 healthy volunteers without any structural heart disease and no cardiac risk factors and from 44 patients with coronary heart disease and ventricular arrhythmias. Beat-to-beat micro-variability measurement of the QRS complex and the ST-T segment was based on 250 consecutive sinus beats per individual. Signal-averaged ECGs were analyzed with the Simson method (QRSD, RMS, LAS). Two RBF networks were trained One on the three signal averaged parameters and one with the 141D variability vector The two soft decisions from each RBF network were then combined by average fusion and maximum detection into a final crisp decision which resulted in an unusually high discriminative accuracy.
{"title":"Decision fusion of micro-variability and signal averaged ECG parameters from the QRS complex with RBF networks","authors":"H. Kestler, A. Muller, V. Hombach, J. Wohrle, O. Grebe, G. Palm, M. Moher, F. Schwenker","doi":"10.1109/CIC.2002.1166767","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166767","url":null,"abstract":"Two types of measurements are usually performed from high resolution ECG recordings: (a) static parameters derived from the signal-averaged QRS complex and (b) variant markers derived from beat-to-beat recordings. It is known that an increased QRS micro-variability and ventricular late potentials are associated with an increased risk for malignant arrhythmias. However, the diagnostic power of the singular parameters is limited In this study we investigated the diagnostic ability of a decision fusion of both variant and static high-resolution ECG parameters with radial-basis-function (RBF) networks. Continuous and signal-averaged ECGs were recorded from 51 healthy volunteers without any structural heart disease and no cardiac risk factors and from 44 patients with coronary heart disease and ventricular arrhythmias. Beat-to-beat micro-variability measurement of the QRS complex and the ST-T segment was based on 250 consecutive sinus beats per individual. Signal-averaged ECGs were analyzed with the Simson method (QRSD, RMS, LAS). Two RBF networks were trained One on the three signal averaged parameters and one with the 141D variability vector The two soft decisions from each RBF network were then combined by average fusion and maximum detection into a final crisp decision which resulted in an unusually high discriminative accuracy.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"297-300"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166767","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62180568","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166742
J. Moraes, M.O. Seixas, F.N. Vilani, E.V. Costa
An unsupervised method to recognize and classify QRS complexes was developed in order to create an automatic cardiac beat classifier in real time. After exhaustive analysis, four features extracted from the QRS complex in the time domain were selected as the ones presenting the best results: width, total sum of the areas under the positive and negative curves, total sum of the absolute values of sample variations and total amplitude. Preliminary studies indicated these features follow a normal distribution, allowing the use of the Mahalanobis distance as their classification criterion. After an initial learning period, the algorithm extracts the four features from every new QRS complex and calculates the Mahalanobis distance between its feature set and the centroids of all existing classes to determine the class in which the new QRS belongs to. If a predefined distance is surpassed, a new class is created Using 44 records from the MIT-BIH we have obtained 90,74% of sensitivity, 96,55% of positive predictivity and 0.242% of false positives.
{"title":"A real time QRS complex classification method using Mahalanobis distance","authors":"J. Moraes, M.O. Seixas, F.N. Vilani, E.V. Costa","doi":"10.1109/CIC.2002.1166742","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166742","url":null,"abstract":"An unsupervised method to recognize and classify QRS complexes was developed in order to create an automatic cardiac beat classifier in real time. After exhaustive analysis, four features extracted from the QRS complex in the time domain were selected as the ones presenting the best results: width, total sum of the areas under the positive and negative curves, total sum of the absolute values of sample variations and total amplitude. Preliminary studies indicated these features follow a normal distribution, allowing the use of the Mahalanobis distance as their classification criterion. After an initial learning period, the algorithm extracts the four features from every new QRS complex and calculates the Mahalanobis distance between its feature set and the centroids of all existing classes to determine the class in which the new QRS belongs to. If a predefined distance is surpassed, a new class is created Using 44 records from the MIT-BIH we have obtained 90,74% of sensitivity, 96,55% of positive predictivity and 0.242% of false positives.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"201-204"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166742","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62180684","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}
Pub Date : 2002-09-22DOI: 10.1109/CIC.2002.1166756
O. Aslanidi, O. Mornev, A. Holden
Mechanisms for termination of re-entry and defibrillation still remain a challenge. Using the Luo-Rudy family of virtual ventricular tissues we simulate termination of re-entrant spiral waves with a periodic low-voltage shock studying a new mechanism for defibrillation. Essential for the simulations is extension of the bidomain tissue representation in order to account for the existence of an external bath ("tridomain"), where the shock is applied The bidomain model with the bath reproduces periodic patterns of depolarization in the virtual tissue - standing waves, previously observed in experiments. In contrast to the classical exponential decay of voltage near the electrodes, standing waves entrain the whole tissue, thus canceling the spiral waves. The mechanism of this far-field effect is based on redistribution of the externally applied current by the conductive bath.
{"title":"Low-voltage defibrillation in bidomain virtual ventricular tissue: effect of the bath","authors":"O. Aslanidi, O. Mornev, A. Holden","doi":"10.1109/CIC.2002.1166756","DOIUrl":"https://doi.org/10.1109/CIC.2002.1166756","url":null,"abstract":"Mechanisms for termination of re-entry and defibrillation still remain a challenge. Using the Luo-Rudy family of virtual ventricular tissues we simulate termination of re-entrant spiral waves with a periodic low-voltage shock studying a new mechanism for defibrillation. Essential for the simulations is extension of the bidomain tissue representation in order to account for the existence of an external bath (\"tridomain\"), where the shock is applied The bidomain model with the bath reproduces periodic patterns of depolarization in the virtual tissue - standing waves, previously observed in experiments. In contrast to the classical exponential decay of voltage near the electrodes, standing waves entrain the whole tissue, thus canceling the spiral waves. The mechanism of this far-field effect is based on redistribution of the externally applied current by the conductive bath.","PeriodicalId":80984,"journal":{"name":"Computers in cardiology","volume":"1 1","pages":"255-258"},"PeriodicalIF":0.0,"publicationDate":"2002-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1109/CIC.2002.1166756","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"62180711","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：