The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Nadir Saoudi - One of the best experts on this subject based on the ideXlab platform.
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Non-invasive prediction of catheter ablation outcome in persistent atrial fibrillation by fibrillatory wave amplitude computation in multiple electrocardiogram Leads.
Archives of cardiovascular diseases, 2016Co-Authors: Vicente Zarzoso, Marianna Meo, Antonio Hidalgo-muñoz, Olivier Meste, Decebal Gabriel Latcu, Irina Popescu, Nadir SaoudiAbstract:Summary Background Catheter ablation (CA) of persistent atrial fibrillation (AF) is challenging, and reported results are capable of improvement. A better patient selection for the procedure could enhance its success rate while avoiding the risks associated with ablation, especially for patients with low odds of favorable outcome. CA outcome can be predicted non-invasively by atrial fibrillatory wave (f-wave) amplitude, but previous works focused mostly on manual measures in single electrocardiogram (ECG) Leads only. Aim To assess the long-term prediction ability of f-wave amplitude when computed in multiple ECG Leads. Methods Sixty-two patients with persistent AF (52 men; mean age 61.5 ± 10.4 years) referred for CA were enrolled. A standard 1-minute 12-lead ECG was acquired before the ablation procedure for each patient. F-wave amplitudes in different ECG Leads were computed by a non-invasive signal processing algorithm, and combined into a mutivariate prediction model based on logistic regression. Results During an average follow-up of 13.9 ± 8.3 months, 47 patients had no AF recurrence after ablation. A lead selection approach relying on the Wald index pointed to I, V1, V2 and V5 as the most relevant ECG Leads to predict jointly CA outcome using f-wave amplitudes, reaching an area under the curve of 0.854, and improving on single-lead amplitude-based predictors. Conclusion Analysing the f-wave amplitude in several ECG Leads simultaneously can significantly improve CA long-term outcome prediction in persistent AF compared with predictors based on single-lead measures.
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Noninvasive Prediction of Catheter Ablation Outcome in Persistent Atrial Fibrillation by Fibrillatory Wave Amplitude Computation in Multiple ECG Leads
Archives of cardiovascular diseases, 2016Co-Authors: Vicente Zarzoso, Marianna Meo, Antonio Hidalgo-muñoz, Olivier Meste, Decebal Gabriel Latcu, Irina Popescu, Nadir SaoudiAbstract:Background. Catheter ablation (CA) of persistent atrial fibrillation (AF) is challenging and reported results are perfectible. Improving patient selection for the procedure could enhance its success rate while avoiding the risks associated with ablation for patients with low odds of success. CA outcome can be predicted noninvasively by atrial fibrillatory wave (f-wave) amplitude, but previous works have mostly focused on manual measures in single ECG Leads only. Aims. The present work aims at assessing the long-term prediction ability of f-wave amplitude when computed in multiple ECG Leads. Methods and Results. Sixty-two persistent AF patients (52 males, 61.5±10.4 years) referred to CA were enrolled in this study. During an average follow-up of 14±8 months, 47 patients had no AF recurrence after ablation. A standard one-minute 12-lead ECG was acquired before the ablation procedure for each patient. F-wave amplitudes in different ECG Leads were computed by a noninvasive signal processing algorithm and combined into a multivariate prediction model based on logistic regression. A lead selection approach relying on the Wald index pointed to I, V1, V2 and V5 as the most relevant ECG Leads to predict jointly CA outcome using f-wave amplitudes, reaching an AUC of 0.854 and improving on single-lead amplitude-based predictors. Conclusion. Analyzing the f-wave amplitude simultaneously in several ECG Leads can significantly improve CA long-term outcome prediction in persistent AF over predictors based on single-lead measures.
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F-wave Amplitude Stability on Multiple Electrocardiogram Leads in Atrial Fibrillation
2015Co-Authors: Marianna Meo, Antonio Hidalgo-muñoz, Vicente Zarzoso, Olivier Meste, Gabriel Decebal Latcu, Nadir SaoudiAbstract:Fibrillatory wave (f-wave) amplitude correlates with left atrium (LA) size in certain electrocardiogram (ECG) Leads and it is regarded as a predictor of ablation therapy outcome for atrial fibrillation (AF). This study aims at assessing the temporal stability of f-wave amplitude measures throughout the recording and determining the minimum signal length necessary to characterize them accurately in ECG Leads. In a set of standard ECGs acquired in 34 persistent AF patients, we determined the minimum temporal window length W such that the related amplitude value accurately correlated with that from the whole atrial activity (AA) signal in Leads I, II, V 1-V 6 (threshold Pearson's correlation coefficient R = 0.9). Subsequently, we tested intrarecord-ing correlation between amplitude values obtained in two distinct W-second AA signal excerpts. This procedure was performed both on the original AA signal and on its principal component analysis (PCA) rank-1 approximation.
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CinC - F-wave amplitude stability on multiple electrocardiogram Leads in atrial fibrillation
2015 Computing in Cardiology Conference (CinC), 2015Co-Authors: Marianna Meo, Antonio Hidalgo-muñoz, Vicente Zarzoso, Olivier Meste, Decebal Gabriel Latcu, Nadir SaoudiAbstract:Fibrillatory wave (f-wave) amplitude correlates with left atrium (LA) size in certain electrocardiogram (ECG) Leads and it is regarded as a predictor of ablation therapy outcome for atrial fibrillation (AF). This study aims at assessing the temporal stability of f-wave amplitude measures throughout the recording and determining the minimum signal length necessary to characterize them accurately in ECG Leads.
Cees A Swenne - One of the best experts on this subject based on the ideXlab platform.
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comparison of standard versus orthogonal ECG Leads for t wave alternans identification
Annals of Noninvasive Electrocardiology, 2012Co-Authors: Laura Burattini, Roberto Burattini, Cees A SwenneAbstract:: T-wave alternans (TWA), an electrophysiologic phenomenon associated with ventricular arrhythmias, is usually detected from selected ECG Leads. TWA amplitude measured in the 12-standard and the 3-orthogonal (vectorcardiographic) Leads were compared here to identify which lead system yields a more adequate detection of TWA as a noninvasive marker for cardiac vulnerability to ventricular arrhythmias. Our adaptive match filter (AMF) was applied to exercise ECG tracings from 58 patients with an implanted cardiac defibrillator, 29 of which had ventricular tachycardia or fibrillation during follow-up (cases), while the remaining 29 were used as controls. Two kinds of TWA indexes were considered, the single-lead indexes, defined as the mean TWA amplitude over each lead (MTWAA), and lead-system indexes, defined as the mean and the maximum MTWAA values over the standard Leads and over the orthogonal Leads. Significantly (P < 0.05) higher TWA in the cases versus controls was identified only occasionally by the single-lead indexes (odds ratio: 1.0-9.9, sensitivity: 24-76%, specificity: 76-86%), and consistently by the lead-system indexes (odds ratio: 4.5-8.3, sensitivity: 57-72%, specificity: 76%). The latter indexes also showed a significant correlation (0.65-0.83) between standard and orthogonal Leads. Hence, when using the AMF, TWA should be detected in all Leads of a system to compute the lead-system indexes, which provide a more reliable TWA identification than single-lead indexes, and a better discrimination of patients at increased risk of cardiac instability. The standard and the orthogonal Leads can be considered equivalent for TWA identification, so that TWA analysis can be limited to one-lead system.
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comparison of standard versus orthogonal ECG Leads for t wave alternans identification
Annals of Noninvasive Electrocardiology, 2012Co-Authors: Laura Burattini, Roberto Burattini, Sumche Man, Cees A SwenneAbstract:T-wave alternans (TWA), an electrophysiologic phenomenon associated with ventricular arrhythmias, is usually detected from selected ECG Leads. TWA amplitude measured in the 12-standard and the 3-orthogonal (vectorcardiographic) Leads were compared here to identify which lead system yields a more adequate detection of TWA as a noninvasive marker for cardiac vulnerability to ventricular arrhythmias. Our adaptive match filter (AMF) was applied to exercise ECG tracings from 58 patients with an implanted cardiac defibrillator, 29 of which had ventricular tachycardia or fibrillation during follow-up (cases), while the remaining 29 were used as controls. Two kinds of TWA indexes were considered, the single-lead indexes, defined as the mean TWA amplitude over each lead (MTWAA), and lead-system indexes, defined as the mean and the maximum MTWAA values over the standard Leads and over the orthogonal Leads. Significantly (P < 0.05) higher TWA in the cases versus controls was identified only occasionally by the single-lead indexes (odds ratio: 1.0-9.9, sensitivity: 24-76%, specificity: 76-86%), and consistently by the lead-system indexes (odds ratio: 4.5-8.3, sensitivity: 57-72%, specificity: 76%). The latter indexes also showed a significant correlation (0.65-0.83) between standard and orthogonal Leads. Hence, when using the AMF, TWA should be detected in all Leads of a system to compute the lead-system indexes, which provide a more reliable TWA identification than single-lead indexes, and a better discrimination of patients at increased risk of cardiac instability. The standard and the orthogonal Leads can be considered equivalent for TWA identification, so that TWA analysis can be limited to one-lead system.
John E. Madias - One of the best experts on this subject based on the ideXlab platform.
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On the nonpathological nature of ST‐segment elevation in lateral Leads in patients with CRBBB
Pacing and clinical electrophysiology : PACE, 2021Co-Authors: John E. MadiasAbstract:Stable ST-segment elevation (STSE) in the lateral electrocardiogram (ECG) Leads (i.e., I, II, aVL, V5, and V6) are frequently encountered in association with stable and transient complete right bundle branch block (CRBBB). These STSE in the lateral ECG Leads in patients with CRBBB, represent parallel changes to the ST-segment depression seen in the V1-V3 Leads, and both represent secondary ECG changes expected in patients with intraventricular conduction delays, and they are opposite in polarity to the latter part of the QRS complexes. Proprietary automated ECG interpretation algorithms provided by the different electrocardiographs associate such ECG changes in the lateral Leads in the presence of CBBB to "lateral myocardial infarction, ischemia, or injury," "pericarditis," or "early repolarization," which results in inappropriate concern among clinicians, and Leads to costly unnecessary diagnostic testing. This piece strives to reassure clinicians about the nonpathological nature of lateral STSE in ECGs with CRBBB.
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Is the T-wave alternans magnitude in apparently healthy subjects and in different subsets of patients with ischaemic heart disease T-wave amplitude dependent?
Europace, 2011Co-Authors: John E. MadiasAbstract:It has been established that T-wave alternans (TWA) is heart rate dependent. Also it has been previously hypothesized that TWA magnitude (TWA-MG) may be T-wave amplitude (TW-AMP) dependent.1Such a speculation is supported by the variation in the TWA-MG in different electrocardiogram (ECG) Leads of the same subject, the larger TWA-MG in the ECG precordial among the ECG Leads, which are characterized by larger TW-AMP, and the larger TWA-MG in ECGs of patients with bundle branch blocks with large secondary T waves, than in the ones with normal intraventricular conduction. If this hypothesis proves to be valid, adjustment of the different TWA-MG values in a single ECG by the corresponding TW-AMP is in order. Also such adjustment of TWA-MG in serial ECGs or …
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Exercise-triggered Transient R-Wave Enhancement and ST-Segment Elevation in II, III, and aVF ECG Leads: A Testament to the "Plasticity" of the QRS Complex During Ischemia
Journal of electrocardiology, 2004Co-Authors: John E. Madias, Mehran AttariAbstract:We describe a patient with coronary artery disease who showed transiently augmented R-waves in his electrocardiogram (ECG) during the course of an exercise treadmill test (ETT), an ECG pattern occasionally associated with the hyperacute phase of myocardial infarction and variant angina. This change in the R-waves was noted in II, III, and aVF ECG Leads and was associated with ST-segment elevation; both changed gradually and were normalized during the recovery period. Cardiac enzymes after ETT were negative, and arteriography revealed 3-vessel coronary artery disease, with a completely occluded right coronary artery. The ventriculogram showed very mild hypokinesis of the inferior left ventricular wall, while the global ejection fraction was 75%. These ECG changes, noted previously during ETT in precordial ECG Leads, are herein reported to occur also in II, III, and aVF ECG Leads. The generation of these ECG changes, which hinges upon a late unopposed depolarization occurring in the course and at the site of severe ischemic injury, constitutes a transient focal ventricular conduction abnormality.
D. Babuty - One of the best experts on this subject based on the ideXlab platform.
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P6585Number of ECG Leads and prognosis of spontaneous type 1 Brugada syndrome
European Heart Journal, 2019Co-Authors: V Probst, M Arnaud, Nathalie Behar, Philippe Mabo, Béatrice Guyomarch, Romain Tixier, J. Briand, P. Berthome, Jacques Mansourati, D. BabutyAbstract:Abstract Introduction Brugada syndrome (BrS) is an inherited arrhythmia syndrome with an increased risk of sudden cardiac death (SCD). The recent single lead-based diagnosis of Brugada syndrome recommended criterion may lead to overdiagnosis of Brugada syndrome and overestimation of the risk of SCD. Objective We aim to investigate the value of a single lead diagnosis in spontaneous type 1 ECG Brugada patient and to investigate the association between the number of ECG Leads with a spontaneous type 1 ST elevation and the arrhythmic risk. Methods Consecutive patients affected with BrS were recruited in a multicentric prospective registry in France (15 centers) between 1994 and 2016. A total of 1613 patients affected by the Brugada syndrome were enrolled. For this specific study, only patient with a spontaneous type 1 BrS were enrolled (n=505). Data were prospectively collected with an average follow-up of 6.5±4.7 years. ECGs were reviewed by 2 physicians blinded to clinical status. Type 1 ST elevation was defined by ≥2 mm J-point elevation with coved ST segment and negative T wave. Results A total of 505 patients with a spontaneous type 1 BrS (mean age 46±15 years, 398 males, 79%) were enrolled. 117 patients (23%) were symptomatic at baseline (32 (6%) aborted SCD, 85 (17%) syncope). Implantable cardiac defibrillator (ICD) was implanted in 191 patients (38%). Brugada ECG pattern was found in 1 lead in 250 patients (50%, group 1), in 2 Leads in 227 patients (45%, group 2) and in 3 Leads in 28 patients (5%, group 3). Groups were comparable in term of clinical presentation except for group 3 who presented more frequently an early repolarization pattern (n=19 (8%) in group 1, n=15 in group 2 (6%) and n=7 (25%) in group 3, p=0.02) and more frequently QRS fragmentation (n=6 (2%) in group 1, n=3 in group 2 (1%) and n=3 (11%) in group 3, p=0.03). During follow-up, 46 (9%) patients presented an arrhythmic event: 22 (9%) in group 1 (4 SCD, 14 appropriate ICD therapy, 4 ventricular arrhythmias), 22 (10%) in group 2 (6 SCD, 11 appropriate ICD therapy, 5 ventricular arrhythmias) and 2 (7%) in group 3 (1 SCD, 1 appropriate ICD therapy). Patients with type 1 BrS pattern in 2 or 3 ECG Leads had not a significantly higher rate of arrhythmic events than patients with type 1 BrS pattern in only 1 ECG lead (HR: 1.1; 95% CI: 0.6–1.9 for group 2 and HR: 0.7; 95% CI: 0.2–3 for group 2; p=0,087). Conclusion In the largest cohort of BrS patients ever described, the prognosis of Brugada syndrome with a spontaneous ECG pattern does not appear to be affected by the number of Leads required for diagnostic.
Irena Jekova - One of the best experts on this subject based on the ideXlab platform.
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Personal Verification/Identification via Analysis of the Peripheral ECG Leads: Influence of the Personal Health Status on the Accuracy
BioMed research international, 2015Co-Authors: Irena Jekova, Giovanni BortolanAbstract:Traditional means for identity validation (PIN codes, passwords), and physiological and behavioral biometric characteristics (fingerprint, iris, and speech) are susceptible to hacker attacks and/or falsification. This paper presents a method for person verification/identification based on correlation of present-to-previous limb ECG Leads: I (r I), II (r II), calculated from them first principal ECG component (r PCA), linear and nonlinear combinations between r I, r II, and r PCA. For the verification task, the one-to-one scenario is applied and threshold values for r I, r II, and r PCA and their combinations are derived. The identification task supposes one-to-many scenario and the tested subject is identified according to the maximal correlation with a previously recorded ECG in a database. The population based ECG-ILSA database of 540 patients (147 healthy subjects, 175 patients with cardiac diseases, and 218 with hypertension) has been considered. In addition a common reference PTB dataset (14 healthy individuals) with short time interval between the two acquisitions has been taken into account. The results on ECG-ILSA database were satisfactory with healthy people, and there was not a significant decrease in nonhealthy patients, demonstrating the robustness of the proposed method. With PTB database, the method provides an identification accuracy of 92.9% and a verification sensitivity and specificity of 100% and 89.9%.
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personal verification identification via analysis of the peripheral ECG Leads influence of the personal health status on the accuracy
BioMed Research International, 2015Co-Authors: Irena Jekova, Giovanni BortolanAbstract:Traditional means for identity validation (PIN codes, passwords), and physiological and behavioral biometric characteristics (fingerprint, iris, and speech) are susceptible to hacker attacks and/or falsification. This paper presents a method for person verification/identification based on correlation of present-to-previous limb ECG Leads: I (r I), II (r II), calculated from them first principal ECG component (r PCA), linear and nonlinear combinations between r I, r II, and r PCA. For the verification task, the one-to-one scenario is applied and threshold values for r I, r II, and r PCA and their combinations are derived. The identification task supposes one-to-many scenario and the tested subject is identified according to the maximal correlation with a previously recorded ECG in a database. The population based ECG-ILSA database of 540 patients (147 healthy subjects, 175 patients with cardiac diseases, and 218 with hypertension) has been considered. In addition a common reference PTB dataset (14 healthy individuals) with short time interval between the two acquisitions has been taken into account. The results on ECG-ILSA database were satisfactory with healthy people, and there was not a significant decrease in nonhealthy patients, demonstrating the robustness of the proposed method. With PTB database, the method provides an identification accuracy of 92.9% and a verification sensitivity and specificity of 100% and 89.9%.
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detection of electrode interchange in right precordial and posterior ECG Leads
Computing in Cardiology Conference, 2015Co-Authors: Irena Jekova, Vessela Krasteva, Remo Leber, Ramun Schmid, Roger AbacherliAbstract:This study presents a method for automated detection of misplaced supplementary precordial Leads, including the right-sided V3R, V4R and the posterior V8, V9 Leads. Considering their uncommon use in clinical routine, a lead reversal is quite probable and could result in erroneous diagnosis and treatment. The method allows real-time implementation by scoring inter-lead cross-correlations over continuous 4s episodes, scanning the normal progression of PQRST waveforms within Leads [V4R, V3R, V3, V4] and [V4, V5, V6, V8, V9]. A large 16-lead ECG database with 1333 chest pain patients is used to test the performance of the method for all possible 23 swaps between the supplementary Leads V4R, V3R, V8, V9, assuming correct positions of the standard V1–V6. The sensitivity (Se) for lead reversals is Se=94.1±4.6%, ranged between 78.5% and 97.8%, with the most difficult detection of V3R/V4R swap (Se=78.5%), V4R/V9 swap (Se=83.7%), V8/V9 swap (Se=91.8%). The achieved specificity for the correct lead positions is Sp=83.4%.
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CinC - Detection of electrode interchange in right precordial and posterior ECG Leads
2015 Computing in Cardiology Conference (CinC), 2015Co-Authors: Irena Jekova, Vessela Krasteva, Remo Leber, Ramun Schmid, Roger AbacherliAbstract:This study presents a method for automated detection of misplaced supplementary precordial Leads, including the right-sided V3R, V4R and the posterior V8, V9 Leads. Considering their uncommon use in clinical routine, a lead reversal is quite probable and could result in erroneous diagnosis and treatment. The method allows real-time implementation by scoring inter-lead cross-correlations over continuous 4s episodes, scanning the normal progression of PQRST waveforms within Leads [V4R, V3R, V3, V4] and [V4, V5, V6, V8, V9]. A large 16-lead ECG database with 1333 chest pain patients is used to test the performance of the method for all possible 23 swaps between the supplementary Leads V4R, V3R, V8, V9, assuming correct positions of the standard V1–V6. The sensitivity (Se) for lead reversals is Se=94.1±4.6%, ranged between 78.5% and 97.8%, with the most difficult detection of V3R/V4R swap (Se=78.5%), V4R/V9 swap (Se=83.7%), V8/V9 swap (Se=91.8%). The achieved specificity for the correct lead positions is Sp=83.4%.
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detection of electrode interchange in precordial and orthogonal ECG Leads
Computing in Cardiology Conference, 2013Co-Authors: Irena Jekova, Vessela Krasteva, Roger AbacherliAbstract:This study presents methods for automated detection of interchanged precordial and orthogonal ECG Leads that may prevent from incorrect diagnosis and treatment. For precordial Leads V1-V6, correlation coefficients of QRS-T patterns and time-alignment of R and S-peaks are assessed. For orthogonal Leads (X,Y,Z), analysis of QRS loops in the frontal plane, a set of correlation coefficients and a time-alignment of Leads are implemented. The methods are elaborated using 15-lead ECG databases - 77 healthy control recordings from PTB database (training), and the total set of 1220 ECGs in CSE database with various arrhythmias (test). The specificity (Sp) for detection of the correct precordial Leads configuration (V1 to V6) is 93.5% (training) and 91% (test) and the mean sensitivity (Se) for 23 simulated most common chest electrode swaps is 95.7% (training) and 95% (test). Sp for detection of the correct orthogonal Leads X,Y,Z is 98.7% (training) and 93.3% (test), while mean Se for 47 reversals of electrode couples A/I, F/H, M/E is 98.5%, equal for both training and test databases.
