The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Shu Zhang - One of the best experts on this subject based on the ideXlab platform.
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Endocardial Mapping and catheter ablation for ventricular fibrillation prevention in brugada syndrome
Journal of Cardiovascular Electrophysiology, 2012Co-Authors: Buncha Sunsaneewitayakul, Suthasinee Thamaree, Shu ZhangAbstract:UNLABELLED: Endocardial Mapping and Ablation of Brugada Syndrome. INTRODUCTION: Brugada syndrome (BS) is characterized by ST-segment elevation in the right precordial electrocardiogram (ECG) leads and episodes of ventricular fibrillation (VF). This study aimed to observe the feasibility of substrate modification by radiofrequency catheter ablation and its effects on VF storm. METHODS AND RESULTS: Ten BS patients (all men; median age 36.5 years) with VF storm (group I, n = 4) and no VF storm (group II, n = 6) were enrolled in the study between August 2007 and December 2008. All patients underwent electrophysiological study using noncontact Mapping. The multielectrode array was placed in the right ventricular outflow tract (RVOT). The isopotential map was analyzed during sinus rhythm and the region that had electrical activity occurring during J point to +60 (J+60) milliseconds interval of the V1 or V2 of surface ECG was considered as the late activation zone (LAZ) and also the substrate for ablation. LAZ was found in RVOT with variable distribution in both groups. Endocardial catheter ablation of the LAZ modified Brugada ECG pattern in 3 of 4 patients (75%) and suppressed VF storm in all 4 patients in group I during long-term follow-up (12-30 months). One patient had complete right bundle branch block from the ablation procedure. CONCLUSIONS: LAZ on RVOT identified by noncontact Mapping may serve as potential VF substrate in BS patients with VF episodes. Radiofrequency ablation on LAZ normalized ECG, suppressed VF storm, and reduced VF recurrence. The procedure is safe and may prevent VF occurrence.
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Endocardial Mapping and catheter ablation for ventricular fibrillation prevention in Brugada syndrome.
Journal of cardiovascular electrophysiology, 2012Co-Authors: Buncha Sunsaneewitayakul, Suthasinee Thamaree, Shu ZhangAbstract:Endocardial Mapping and Ablation of Brugada Syndrome. Brugada syndrome (BS) is characterized by ST-segment elevation in the right precordial electrocardiogram (ECG) leads and episodes of ventricular fibrillation (VF). This study aimed to observe the feasibility of substrate modification by radiofrequency catheter ablation and its effects on VF storm. Ten BS patients (all men; median age 36.5 years) with VF storm (group I, n = 4) and no VF storm (group II, n = 6) were enrolled in the study between August 2007 and December 2008. All patients underwent electrophysiological study using noncontact Mapping. The multielectrode array was placed in the right ventricular outflow tract (RVOT). The isopotential map was analyzed during sinus rhythm and the region that had electrical activity occurring during J point to +60 (J+60) milliseconds interval of the V1 or V2 of surface ECG was considered as the late activation zone (LAZ) and also the substrate for ablation. LAZ was found in RVOT with variable distribution in both groups. Endocardial catheter ablation of the LAZ modified Brugada ECG pattern in 3 of 4 patients (75%) and suppressed VF storm in all 4 patients in group I during long-term follow-up (12-30 months). One patient had complete right bundle branch block from the ablation procedure. LAZ on RVOT identified by noncontact Mapping may serve as potential VF substrate in BS patients with VF episodes. Radiofrequency ablation on LAZ normalized ECG, suppressed VF storm, and reduced VF recurrence. The procedure is safe and may prevent VF occurrence. © 2012 Wiley Periodicals, Inc.
Wyn D Davies - One of the best experts on this subject based on the ideXlab platform.
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Endocardial Mapping of atrial fibrillation in the human right atrium using a non contact catheter
European Heart Journal, 2000Co-Authors: Richard J. Schilling, Jeffrey J. Goldberger, Alan H. Kadish, Nicholas S. Peters, Wyn D DaviesAbstract:Background Endocardial Mapping of atrial fibrillation in humans is limited by its low resolution and by complexities in the arrhythmia and atrial anatomy. Methods and Results A catheter mounted non-contact multielectrode was deployed in the right atrium of 11 patients with atrial fibrillation and used to reconstruct 3360 electrograms, superimposed onto a computer-simulated model of the endocardium, using inverse solution mathematics. This allows construction of isopotential maps of the right atrium. Patients had either sustained atrial fibrillation (n=3) for >6 months or developed atrial fibrillation during the study (n=8). Spontaneous initiation of atrial fibrillation was recorded in one patient and was demonstrated by the non-contact system to arise from two successive atrial ectopic beats from the site of a roving contact catheter. Reconstruction of electrograms recorded during atrial fibrillation was validated by comparison with contact electrograms with cross-correlation. During established atrial fibrillation, four patients predominantly had a single right atrial wave front, two had two wave fronts and five patients had three to five wave fronts for most of the time. Periods of electrical silence were seen in the right atrium in eight patients, after which, activity emerged from consistent septal sites alone, suggesting a left atrial origin. During intravenous administration of flecainide, atrial fibrillation in two patients terminated spontaneously or following pacing manoeuvres, while in the remaining patient sinus rhythm was restored via atrial tachycardia. Conclusion Non-contact Mapping of the right atrium has demonstrated modes of initiation and termination of atrial fibrillation, characterized different patterns of right atrial activation in atrial fibrillation and suggests that the left atrium may sustain atrial fibrillation in some patients. Simultaneous Mapping of the right and left atrium is required to further elucidate the mechanisms of human atrial fibrillation.
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Endocardial Mapping of atrial fibrillation in the human right atrium using a non contact catheter
European Heart Journal, 2000Co-Authors: Richard J. Schilling, Jeffrey J. Goldberger, Alan H. Kadish, Nicholas S. Peters, Wyn D DaviesAbstract:BACKGROUND: Endocardial Mapping of atrial fibrillation in humans is limited by its low resolution and by complexities in the arrhythmia and atrial anatomy. METHODS AND RESULTS: A catheter mounted non-contact multielectrode was deployed in the right atrium of 11 patients with atrial fibrillation and used to reconstruct 3360 electrograms, superimposed onto a computer-simulated model of the endocardium, using inverse solution mathematics. This allows construction of isopotential maps of the right atrium. Patients had either sustained atrial fibrillation (n=3) for >6 months or developed atrial fibrillation during the study (n=8). Spontaneous initiation of atrial fibrillation was recorded in one patient and was demonstrated by the non-contact system to arise from two successive atrial ectopic beats from the site of a roving contact catheter. Reconstruction of electrograms recorded during atrial fibrillation was validated by comparison with contact electrograms with cross-correlation. During established atrial fibrillation, four patients predominantly had a single right atrial wave front, two had two wave fronts and five patients had three to five wave fronts for most of the time. Periods of electrical silence were seen in the right atrium in eight patients, after which, activity emerged from consistent septal sites alone, suggesting a left atrial origin. During intravenous administration of flecainide, atrial fibrillation in two patients terminated spontaneously or following pacing manoeuvres, while in the remaining patient sinus rhythm was restored via atrial tachycardia. CONCLUSION: Non-contact Mapping of the right atrium has demonstrated modes of initiation and termination of atrial fibrillation, characterized different patterns of right atrial activation in atrial fibrillation and suggests that the left atrium may sustain atrial fibrillation in some patients. Simultaneous Mapping of the right and left atrium is required to further elucidate the mechanisms of human atrial fibrillation.
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feasibility of a noncontact catheter for Endocardial Mapping of human ventricular tachycardia
Circulation, 1999Co-Authors: Richard J. Schilling, Nicholas S. Peters, Wyn D DaviesAbstract:Background—Catheter ablation of ventricular tachycardia (VT) is limited by difficulty in identifying suitable sites for ablation. This study assesses use of a system capable of simultaneous Endocardial Mapping of the human left ventricle to map and guide radiofrequency (RF) catheter ablation of VT. Methods and Results—A catheter-mounted noncontact multielectrode array was used to reconstruct 3360 electrograms, superimposed onto a computer-simulated Endocardial model. Of 24 patients studied, 20 had ischemic heart disease. Exit sites were demonstrated by the noncontact system in 80 (99%) of 81 VTs, with complete VT circuits traced in 17 (21%). In another 37 VTs, 36±30% (mean±SD) of the diastolic interval was identified. Thirty-eight VT morphologies were ablated with 154 RF energy applications. Successful ablation was achieved by 77% of RF applications to relevant diastolic activity identified by the system and was significantly more likely (P<0.0001) than by RF at the VT exit or remote from diastolic activa...
Buncha Sunsaneewitayakul - One of the best experts on this subject based on the ideXlab platform.
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Endocardial Mapping and catheter ablation for ventricular fibrillation prevention in brugada syndrome
Journal of Cardiovascular Electrophysiology, 2012Co-Authors: Buncha Sunsaneewitayakul, Suthasinee Thamaree, Shu ZhangAbstract:UNLABELLED: Endocardial Mapping and Ablation of Brugada Syndrome. INTRODUCTION: Brugada syndrome (BS) is characterized by ST-segment elevation in the right precordial electrocardiogram (ECG) leads and episodes of ventricular fibrillation (VF). This study aimed to observe the feasibility of substrate modification by radiofrequency catheter ablation and its effects on VF storm. METHODS AND RESULTS: Ten BS patients (all men; median age 36.5 years) with VF storm (group I, n = 4) and no VF storm (group II, n = 6) were enrolled in the study between August 2007 and December 2008. All patients underwent electrophysiological study using noncontact Mapping. The multielectrode array was placed in the right ventricular outflow tract (RVOT). The isopotential map was analyzed during sinus rhythm and the region that had electrical activity occurring during J point to +60 (J+60) milliseconds interval of the V1 or V2 of surface ECG was considered as the late activation zone (LAZ) and also the substrate for ablation. LAZ was found in RVOT with variable distribution in both groups. Endocardial catheter ablation of the LAZ modified Brugada ECG pattern in 3 of 4 patients (75%) and suppressed VF storm in all 4 patients in group I during long-term follow-up (12-30 months). One patient had complete right bundle branch block from the ablation procedure. CONCLUSIONS: LAZ on RVOT identified by noncontact Mapping may serve as potential VF substrate in BS patients with VF episodes. Radiofrequency ablation on LAZ normalized ECG, suppressed VF storm, and reduced VF recurrence. The procedure is safe and may prevent VF occurrence.
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Endocardial Mapping and catheter ablation for ventricular fibrillation prevention in Brugada syndrome.
Journal of cardiovascular electrophysiology, 2012Co-Authors: Buncha Sunsaneewitayakul, Suthasinee Thamaree, Shu ZhangAbstract:Endocardial Mapping and Ablation of Brugada Syndrome. Brugada syndrome (BS) is characterized by ST-segment elevation in the right precordial electrocardiogram (ECG) leads and episodes of ventricular fibrillation (VF). This study aimed to observe the feasibility of substrate modification by radiofrequency catheter ablation and its effects on VF storm. Ten BS patients (all men; median age 36.5 years) with VF storm (group I, n = 4) and no VF storm (group II, n = 6) were enrolled in the study between August 2007 and December 2008. All patients underwent electrophysiological study using noncontact Mapping. The multielectrode array was placed in the right ventricular outflow tract (RVOT). The isopotential map was analyzed during sinus rhythm and the region that had electrical activity occurring during J point to +60 (J+60) milliseconds interval of the V1 or V2 of surface ECG was considered as the late activation zone (LAZ) and also the substrate for ablation. LAZ was found in RVOT with variable distribution in both groups. Endocardial catheter ablation of the LAZ modified Brugada ECG pattern in 3 of 4 patients (75%) and suppressed VF storm in all 4 patients in group I during long-term follow-up (12-30 months). One patient had complete right bundle branch block from the ablation procedure. LAZ on RVOT identified by noncontact Mapping may serve as potential VF substrate in BS patients with VF episodes. Radiofrequency ablation on LAZ normalized ECG, suppressed VF storm, and reduced VF recurrence. The procedure is safe and may prevent VF occurrence. © 2012 Wiley Periodicals, Inc.
Lars Eckardt - One of the best experts on this subject based on the ideXlab platform.
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Endocardial Mapping of right ventricular outflow tract tachycardia using noncontact activation Mapping
Journal of Cardiovascular Electrophysiology, 2003Co-Authors: Michael Ribbing, Günter Breithardt, Kristina Wasmer, Gerold Monnig, Paulus Kirchhof, Wilhelm Haverkamp, Lars EckardtAbstract:Introduction: Activation Mapping and pace Mapping identify successful ablation sites for catheter ablation of right ventricular outflow tract (RVOT) tachycardia. These methods are limited in patients with nonsustained tachycardia or isolated ventricular ectopic beats. We investigated the feasibility of using noncontact Mapping to guide the ablation of RVOT arrhythmias. Methods and Results: Nine patients with RVOT tachycardia and three patients with ectopic beats were studied using noncontact Mapping. A multielectrode array catheter was introduced into the RVOT and tachycardia was analyzed using a virtual geometry. The earliest Endocardial activation estimated by virtual electrograms was displayed on an isopotential color map and measured33 ± 13 msecbefore onset of QRS. Virtual unipolar electrograms at this site demonstrated QS morphology. Guided by a locator signal, ablation was performed with a mean of6.9 ± 2.2radiofrequency deliveries. Acute success was achieved in all patients. During follow-up, one patient had a recurrence of RVOT tachycardia. Compared with patients(n = 21)who underwent catheter ablation using a conventional approach, a higher success rate was achieved by noncontact Mapping. Procedure time was significantly longer in the noncontact Mapping group. Fluoroscopy time was not significantly different in the two groups. Conclusion: Noncontact Mapping can be used as a reliable tool to identify the site of earliest Endocardial activation and to guide the ablation procedure in patients with RVOT tachycardia and in patients with ectopic beats originating from the RVOT. (J Cardiovasc Electrophysiol, Vol. 14, pp. 602-608, June 2003)
Günter Breithardt - One of the best experts on this subject based on the ideXlab platform.
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Endocardial Mapping of right ventricular outflow tract tachycardia using noncontact activation Mapping
Journal of Cardiovascular Electrophysiology, 2003Co-Authors: Michael Ribbing, Günter Breithardt, Kristina Wasmer, Gerold Monnig, Paulus Kirchhof, Wilhelm Haverkamp, Lars EckardtAbstract:Introduction: Activation Mapping and pace Mapping identify successful ablation sites for catheter ablation of right ventricular outflow tract (RVOT) tachycardia. These methods are limited in patients with nonsustained tachycardia or isolated ventricular ectopic beats. We investigated the feasibility of using noncontact Mapping to guide the ablation of RVOT arrhythmias. Methods and Results: Nine patients with RVOT tachycardia and three patients with ectopic beats were studied using noncontact Mapping. A multielectrode array catheter was introduced into the RVOT and tachycardia was analyzed using a virtual geometry. The earliest Endocardial activation estimated by virtual electrograms was displayed on an isopotential color map and measured33 ± 13 msecbefore onset of QRS. Virtual unipolar electrograms at this site demonstrated QS morphology. Guided by a locator signal, ablation was performed with a mean of6.9 ± 2.2radiofrequency deliveries. Acute success was achieved in all patients. During follow-up, one patient had a recurrence of RVOT tachycardia. Compared with patients(n = 21)who underwent catheter ablation using a conventional approach, a higher success rate was achieved by noncontact Mapping. Procedure time was significantly longer in the noncontact Mapping group. Fluoroscopy time was not significantly different in the two groups. Conclusion: Noncontact Mapping can be used as a reliable tool to identify the site of earliest Endocardial activation and to guide the ablation procedure in patients with RVOT tachycardia and in patients with ectopic beats originating from the RVOT. (J Cardiovasc Electrophysiol, Vol. 14, pp. 602-608, June 2003)
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Relation between ventricular late Endocardial activity during intraoperative Endocardial Mapping and low-amplitude signals within the terminal QRS complex on the signal-averaged surface electrocardiogram.
American Journal of Cardiology, 1990Co-Authors: Hans-joachim Schwarzmaier, U. Karbenn, Martin Borggrefe, Jörg Ostermeyer, Günter BreithardtAbstract:Noninvasive recording of ventricular late potentials and intraoperative Endocardial Mapping at 36 sites were performed in 24 patients with left ventricular aneurysm and drug-resistant sustained ventricular tachycardia due to coronary artery disease. Their mean age was 55 ± 8 years. Mean ejection fraction was 28 ± 12%. For detection of late potentials on the signal-averaged QRS complex, 3 different algorithms were used. Late potentials were found in 54, 67 and 67% of the patients, respectively. In patients with a late potential on the signal-averaged electrocardiogram (ECG), delayed local activation (>40 ms beyond the QRS complex on the intraoperative surface ECG) was recorded at 5.5, 5.5 and 5.6 Endocardial sites. In patients without a late potential, this type of delayed local activation was detected at 2.4, 1.1 and 0.9 of 36 Endocardial sites, respectively (p < 0.05; p < 0.01; p < 0.002). The mean delay of local Endocardial activity was 38, 35 and 37 ms in patients with a late potential on the body surface recording versus 20, 19 and 11 ms, respectively, in patients without a late potential (p < 0.05; p < 0.05; p < 0.002). There was no correlation between the duration or amplitude of the late potential, if present, and the number of Endocardial sites exhibiting delayed activity (r = −0.23, r = −0.05, r = 0.21; correlation not significant for each) or the mean duration of the Endocardial delayed activity (r = -0.25, r = -0.14, r = −0.07; correlation not significant for each). These results indicate that the presence of late potentials on the signal-averaged surface ECG is related to the mean duration of Endocardial late activity as well as to the number of Endocardial sites exhibiting a given degree of delayed activation. Thus, it is dependent on the mass of slowly activated tissue. However, a direct conclusion from the duration or the amplitude of a late potential to the amount of delayed activation or the extent of Endocardial time delay does not seem possible.