The Experts below are selected from a list of 3228 Experts worldwide ranked by ideXlab platform
John B Uther - One of the best experts on this subject based on the ideXlab platform.
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does the induction of Ventricular Flutter or fibrillation at electrophysiologic testing after myocardial infarction have any prognostic significance
American Journal of Cardiology, 1995Co-Authors: John P Bourke, David Richards, David L Ross, Mark A Mcguire, John B UtherAbstract:Abstract This study examines the significance of inducing sustained Ventricular fibrillation (VF) or Ventricular Flutter by programmed stimulation after infarction. Programmed Ventricular stimulation was performed for prognostic reasons from the right Ventricular apex at twice diastolic threshold using a protocol containing 4 extrastimuli. Of 502 patients tested 11 ± 4 days after acute infarction, VF was induced in 164 (33%), Ventricular Flutter in 134 (27%), Ventricular tachycardia (VT) in 44 (9%), and no arrhythmia in 160 (32%). All groups were similar in age, sex distribution, and sites of index infarction. Those with inducible VT had a higher incidence of multiple infarctions and a lower mean left Ventricular ejection fraction at the time of testing. Without antiarrhythmic drug therapy, 8 patients (18%) with inducible VT experienced spontaneous VT or died instantaneously during the first year of follow-up. By contrast, only 1 (0.6%) patient with inducible VF, 1 (0.7%) with Ventricular Flutter, and 1 (0.6%) without any inducible arrhythmias experienced similar events in the same period (p 230 ms indicates patients with Ventricular electrical instability after infarction. The induction of VF or Ventricular Flutter is a negative test result with no adverse long-term prognostic significance.
Raja Majid Mehmood - One of the best experts on this subject based on the ideXlab platform.
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classification of arrhythmia by using deep learning with 2 d ecg spectral image representation
Remote Sensing, 2020Co-Authors: Amin Ullah, Syed Muhammad Anwar, Muhammad Bilal, Raja Majid MehmoodAbstract:The electrocardiogram (ECG) is one of the most extensively employed signals used in the diagnosis and prediction of cardiovascular diseases (CVDs). The ECG signals can capture the heart’s rhythmic irregularities, commonly known as arrhythmias. A careful study of ECG signals is crucial for precise diagnoses of patients’ acute and chronic heart conditions. In this study, we propose a two-dimensional (2-D) convolutional neural network (CNN) model for the classification of ECG signals into eight classes; namely, normal beat, premature Ventricular contraction beat, paced beat, right bundle branch block beat, left bundle branch block beat, atrial premature contraction beat, Ventricular Flutter wave beat, and Ventricular escape beat. The one-dimensional ECG time series signals are transformed into 2-D spectrograms through short-time Fourier transform. The 2-D CNN model consisting of four convolutional layers and four pooling layers is designed for extracting robust features from the input spectrograms. Our proposed methodology is evaluated on a publicly available MIT-BIH arrhythmia dataset. We achieved a state-of-the-art average classification accuracy of 99.11%, which is better than those of recently reported results in classifying similar types of arrhythmias. The performance is significant in other indices as well, including sensitivity and specificity, which indicates the success of the proposed method.
Sami Viskin - One of the best experts on this subject based on the ideXlab platform.
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long term prognosis of inducible Ventricular Flutter not an innocent finding
American Heart Journal, 2004Co-Authors: Osnat Gurevitz, Sami Viskin, Michael Glikson, Karla V Ballman, Gabriela A Rosales, Win Kuang Shen, Stephen C Hammill, Paul A FriedmanAbstract:Abstract Background The prognostic significance of Ventricular Flutter (VFL) induced during programmed electrical stimulation (PES) is currently unknown. Methods This study examined patients who had PES-induced VFL and assessed their long-term prognosis compared with patients who had inducible sustained monomorphic Ventricular tachycardia (SMVT). Results Of 3414 patients undergoing PES, 74 (2%) had sustained VFL. They were compared with a group of 71 patients undergoing PES in the same time frame who had inducible SMVT. Patients with inducible VFL had a higher ejection fraction than patients with SMVT (0.39 vs 0.33; P = .05). More aggressive pacing was required for arrhythmia induction in patients with VFL, with more stimuli (2.7 ± 0.5 vs 2.2 ± 0.6; P 2 , S 3 , and S 4 intervals. After a mean follow-up of 30 ± 31 months, the mortality rate was 34% in patients with VFL and 30% in patients with SMVT ( P = .41). No difference in the 2 groups in overall survival or a combined end point of sudden death or appropriate implantable cardioverter defibrillator shock was revealed with Kaplan-Meier analysis. Conclusion The long-term prognosis of patients with inducible VFL is similar to that of patients with inducible SMVT, even when VFL is induced with a relatively aggressive protocol.
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Ventricular Flutter induced during electrophysiologic studies in patients with old myocardial infarction clinical and electrophysiologic predictors and prognostic significance
Journal of Cardiovascular Electrophysiology, 2003Co-Authors: Sami Viskin, Maya Ishshalom, Edward Koifman, Uri Rozovski, David Zeltser, Aharon Glick, Ariel Finkelstein, Amir Halkin, Roman Fish, Bernard BelhassenAbstract:Introduction: Induction of Ventricular Flutter during electrophysiologic (EP) studies (similar to that of Ventricular fibrillation [VF]) often is viewed as a nonspecific response with limited prognostic significance. However, data supporting this dogma originate from patients without previously documented Ventricular tachyarrhythmias. We examined the significance of Ventricular Flutter in patients with and without spontaneous Ventricular arrhythmias. Methods and Results: We conducted a cohort study of all patients with myocardial infarction (MI) undergoing EP studies at our institution. Of 344 consecutive patients, 181 had previously documented spontaneous sustained Ventricular arrhythmias, 61 had suspected Ventricular arrhythmias, and 102 had neither. Ventricular Flutter was induced in 65 (19%) of the patients. Left Ventricular ejection fraction was highest among patients with inducible VF (35 ± 13), lowest for patients with inducible sustained monomorphic Ventricular tachycardia (SMVT; 27 ± 9), and intermediate for patients with inducible Ventricular Flutter (30 ± 10). Similarly, the coupling intervals needed to induce the arrhythmia were shortest for VF (200 ± 28 msec), intermediate for Ventricular Flutter (209 ± 27 msec), and longest for SMVT (230 ± 35 msec). During 5 ± 8 years of follow-up, the risk for Ventricular tachycardia/VF was high for patients with SMVT and Ventricular Flutter and low for patients with inducible VF and noninducible patients (46%, 34%, 17%, and 14%, P < 0.005). Conclusion: Patients with inducible Ventricular Flutter appear to be “intermediate” between patients with inducible VF and patients with SMVT in terms of clinical and electrophysiologic correlates. However, the prognostic value of inducible Ventricular Flutter is comparable to that of SMVT. (J Cardiovasc Electrophysiol, Vol. 14, pp. 913-919, September 2003)
Mark S Link - One of the best experts on this subject based on the ideXlab platform.
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prophylactic implantable defibrillator in patients with arrhythmogenic right Ventricular cardiomyopathy dysplasia and no prior Ventricular fibrillation or sustained Ventricular tachycardia
Circulation, 2010Co-Authors: Domenico Corrado, Mark S Link, Hugh Calkins, Loira Leoni, Stefano Favale, Michela Bevilacqua, Cristina Basso, Deirdre Ward, Giuseppe Boriani, Renato Pietro RicciAbstract:Background—The role of implantable cardioverter-defibrillator (ICD) in patients with arrhythmogenic right Ventricular cardiomyopathy/dysplasia and no prior Ventricular fibrillation (VF) or sustained Ventricular tachycardia is an unsolved issue. Methods and Results—We studied 106 consecutive patients (62 men and 44 women; age, 35.6±18 years) with arrhythmogenic right Ventricular cardiomyopathy/dysplasia who received an ICD based on 1 or more arrhythmic risk factors such as syncope, nonsustained Ventricular tachycardia, familial sudden death, and inducibility at programmed Ventricular stimulation. During follow-up of 58±35 months, 25 patients (24%) had appropriate ICD interventions and 17 (16%) had shocks for life-threatening VF or Ventricular Flutter. At 48 months, the actual survival rate was 100% compared with the VF/Ventricular Flutter–free survival rate of 77% (log-rank P=0.01). Syncope significantly predicted any appropriate ICD interventions (hazard ratio, 2.94; 95% confidence interval, 1.83 to 4.67;...
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inducible Ventricular Flutter and fibrillation predict for arrhythmia occurrence in coronary artery disease patients presenting with syncope of unknown origin
Journal of Cardiovascular Electrophysiology, 2002Co-Authors: Mark S Link, Mohammad Saeed, Neera Gupta, Munther K Homoud, Paul J Wang, N Mark A EstesAbstract:Ventricular Fibrillation and Syncope.Introduction: Ventricular fibrillation and Ventricular Flutter (cycle length ≤230 msec) induced at electrophysiologic studies are thought to be nonspecific findings in patients presenting with syncope of unknown origin. However, there are limited data on the prognosis of these patients in long-term follow-up. Methods and Results: We followed 274 consecutive patients with coronary artery disease presenting with syncope or presyncope who underwent electrophysiologic studies from January 1992 to June 1999 and assessed the risk of subsequent arrhythmias stratified by the electrophysiologic result at the time of their presentation with syncope. Ventricular fibrillation was induced in 23 patients (8%); Ventricular Flutter in 24 (9%), sustained Ventricular tachycardia in 41 (15%); and nonsustained Ventricular tachycardia 42 (15%). In 37 ± 25 months of follow-up, there have been Ventricular arrhythmias in 34 patients, including 3 (13%) of 23 who had induced Ventricular fibrillation, and 7 (30%) of 24 with induced Ventricular Flutter, compared to 13 (32%) of 41 with sustained Ventricular tachycardia, 7 (17%) of 42 with nonsustained Ventricular tachycardia, and only 4 (3%) of 144 noninducible patients (P < 0.001 for induced Ventricular fibrillation and Ventricular Flutter vs noninducible patients). The inducibility of Ventricular fibrillation and Ventricular Flutter were independent risk factors for arrhythmia occurrence in follow-up. Conclusion: Ventricular fibrillation and Ventricular Flutter induced at electrophysiologic studies have prognostic significance for arrhythmia occurrence in patients presenting with syncope. These induced arrhythmias may not be as nonspecific as previously thought and treatment should be considered for these patients.
Bernard Belhassen - One of the best experts on this subject based on the ideXlab platform.
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Ventricular Flutter induced during electrophysiologic studies in patients with old myocardial infarction clinical and electrophysiologic predictors and prognostic significance
Journal of Cardiovascular Electrophysiology, 2003Co-Authors: Sami Viskin, Maya Ishshalom, Edward Koifman, Uri Rozovski, David Zeltser, Aharon Glick, Ariel Finkelstein, Amir Halkin, Roman Fish, Bernard BelhassenAbstract:Introduction: Induction of Ventricular Flutter during electrophysiologic (EP) studies (similar to that of Ventricular fibrillation [VF]) often is viewed as a nonspecific response with limited prognostic significance. However, data supporting this dogma originate from patients without previously documented Ventricular tachyarrhythmias. We examined the significance of Ventricular Flutter in patients with and without spontaneous Ventricular arrhythmias. Methods and Results: We conducted a cohort study of all patients with myocardial infarction (MI) undergoing EP studies at our institution. Of 344 consecutive patients, 181 had previously documented spontaneous sustained Ventricular arrhythmias, 61 had suspected Ventricular arrhythmias, and 102 had neither. Ventricular Flutter was induced in 65 (19%) of the patients. Left Ventricular ejection fraction was highest among patients with inducible VF (35 ± 13), lowest for patients with inducible sustained monomorphic Ventricular tachycardia (SMVT; 27 ± 9), and intermediate for patients with inducible Ventricular Flutter (30 ± 10). Similarly, the coupling intervals needed to induce the arrhythmia were shortest for VF (200 ± 28 msec), intermediate for Ventricular Flutter (209 ± 27 msec), and longest for SMVT (230 ± 35 msec). During 5 ± 8 years of follow-up, the risk for Ventricular tachycardia/VF was high for patients with SMVT and Ventricular Flutter and low for patients with inducible VF and noninducible patients (46%, 34%, 17%, and 14%, P < 0.005). Conclusion: Patients with inducible Ventricular Flutter appear to be “intermediate” between patients with inducible VF and patients with SMVT in terms of clinical and electrophysiologic correlates. However, the prognostic value of inducible Ventricular Flutter is comparable to that of SMVT. (J Cardiovasc Electrophysiol, Vol. 14, pp. 913-919, September 2003)
