The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Bradley P. Knight - One of the best experts on this subject based on the ideXlab platform.
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a prospective comparison of cardiac imaging using Intracardiac echocardiography with transesophageal echocardiography in patients with atrial fibrillation
Circulation-arrhythmia and Electrophysiology, 2010Co-Authors: Sanjeev Saksena, Bradley P. Knight, Luc Jordaens, Fred Kusumoto, Andrea Natale, Abraham G Kocheril, Navin C Nanda, Rangadham Nagarakanti, Ann Marie Simon, Mary A ViggianoAbstract:Background—The Intracardiac Echocardiography Guided Cardioversion Helps Interventional Procedures study evaluated the concordance of Intracardiac echocardiography (ICE) with transesophageal echocar...
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the use of Intracardiac echocardiography and other Intracardiac imaging tools to guide noncoronary cardiac interventions
Journal of the American College of Cardiology, 2009Co-Authors: Ziyad M Hijazi, Roberto M Lang, Bradley P. KnightAbstract:The limitations of standard fluoroscopy have led to the development of improved imaging techniques to guide noncoronary cardiac interventions. Imaging tools that are used in the interventional laboratory can be categorized as invasive and noninvasive. Noninvasive cardiac imaging tools include ultrasound, computed tomography, and magnetic resonance imaging. These modalities can generate high-resolution images of the heart and are increasingly being used to guide cardiac interventions. Despite these advances, there remains a strong role for invasive imaging tools in the interventional laboratories. Such invasive imaging tools include transesophageal echocardiography, Intracardiac echocardiography, Intracardiac endoscopy, and electroanatomic mapping systems. Despite the risks inherent to the invasive nature of these tools, these modalities can provide excellent real-time, detailed images that can be invaluable in guiding certain cardiac interventions. This review will propose the features of an ideal Intracardiac imaging tool, summarize the Intracardiac imaging tools that are currently available or under development to guide noncoronary cardiac interventional procedures, and suggest opportunities for improvement. One opportunity in this field is to couple imaging systems directly with the interventional devices themselves. The use of Intracardiac imaging to guide select cardiac procedures including transseptal catheterization, catheter ablation procedures for arrhythmias, and percutaneous placement of cardiac valves and closure devices will also be discussed. Most of this review will be devoted to Intracardiac echocardiography, which currently has the broadest number of applications.
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The Use of Intracardiac Echocardiography and Other Intracardiac Imaging Tools to Guide Noncoronary Cardiac Interventions
Journal of the American College of Cardiology, 2009Co-Authors: Susan S. Kim, Ziyad M Hijazi, Roberto M Lang, Bradley P. KnightAbstract:The limitations of standard fluoroscopy have led to the development of improved imaging techniques to guide noncoronary cardiac interventions. Imaging tools that are used in the interventional laboratory can be categorized as invasive and noninvasive. Noninvasive cardiac imaging tools include ultrasound, computed tomography, and magnetic resonance imaging. These modalities can generate high-resolution images of the heart and are increasingly being used to guide cardiac interventions. Despite these advances, there remains a strong role for invasive imaging tools in the interventional laboratories. Such invasive imaging tools include transesophageal echocardiography, Intracardiac echocardiography, Intracardiac endoscopy, and electroanatomic mapping systems. Despite the risks inherent to the invasive nature of these tools, these modalities can provide excellent real-time, detailed images that can be invaluable in guiding certain cardiac interventions. This review will propose the features of an ideal Intracardiac imaging tool, summarize the Intracardiac imaging tools that are currently available or under development to guide noncoronary cardiac interventional procedures, and suggest opportunities for improvement. One opportunity in this field is to couple imaging systems directly with the interventional devices themselves. The use of Intracardiac imaging to guide select cardiac procedures including transseptal catheterization, catheter ablation procedures for arrhythmias, and percutaneous placement of cardiac valves and closure devices will also be discussed. Most of this review will be devoted to Intracardiac echocardiography, which currently has the broadest number of applications. © 2009 American College of Cardiology Foundation.
Michael D Lesh - One of the best experts on this subject based on the ideXlab platform.
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biophysical characteristics of radiofrequency lesion formation in vivo dynamics of catheter tip tissue contact evaluated by Intracardiac echocardiography
American Heart Journal, 1997Co-Authors: Jonathan M Kalman, Adam P Fitzpatrick, Michael C Chin, Jeffrey E Olgin, Melvin M Scheinman, Michael D LeshAbstract:Abstract During clinical radiofrequency catheter ablation a wide range of delivered power may be necessary to achieve success despite an apparently stable catheter position on fluoroscopy. The purpose of this study was to use Intracardiac echocardiography to characterize the relation between catheter tip–tissue contact and the efficiency of heating during applications of radiofrequency energy in vivo and to determine whether Intracardiac echocardiography could be used prospectively to improve tissue contact. A closed-loop temperature feedback control system was used during radiofrequency applications at five anatomic regions in the right atrium of 15 anesthetized dogs to ensure achievement of a predetermined temperature (70° C) at the catheter tip thermistor by automatic adjustment of delivered power (maximum 100 W). The efficiency-of-heating index was defined as the ratio of steady-state temperature (degrees Celsius) to power (watts). Two-dimensional Intracardiac echocardiography was used to evaluate movement of the catheter tip relative to the endocardium. Perpendicular contact was scored as good, average, or poor and lateral catheter sliding as 5 mm. Two groups of animals were included: group 1, in which tissue contact was guided by fluoroscopic and electrographic criteria for stability of contact, with Intracardiac echocardiography used simply to observe the application; and group 2, in which tissue contact was guided by Intracardiac echocardiography. Of 66 applications, 18 (27.3%) had poor perpendicular contact on echocardiography, and 12 (18.2%) demonstrated lateral sliding of >5 mm even though they had been considered to have good tissue contact by fluoroscopic and electrographic criteria. Perpendicular catheter contact and anatomic location were shown to be independently related to the efficiency-of-heating index. Applications with good perpendicular contact had a significantly higher efficiency-of-heating index and a significantly greater lesion size than those with average or poor contact. The percentage of applications having good perpendicular tissue contact and the lesion size were significantly greater when tissue contact was guided by Intracardiac echocardiography compared with fluoroscopic and electrographic guidance. This study demonstrates that variations in catheter tip–tissue contact account for differences in the efficiency of tissue heating, independently of the anatomic site of the application. Poor tissue contact was observed by Intracardiac echocardiography and confirmed by indexes of tissue heating in approximately one third of radiofrequency applications despite a fluoroscopic appearance and electrographic morphologic appearance suggestive of good tissue contact. There was a significant correlation between echocardiographic evaluation of tissue contact, parameters of tissue heating (efficiency-of-heating index), and lesion size. In addition, Intracardiac echocardiography could be used prospectively to improve the percentage of good contact applications and increase the lesion size. (Am Heart J 1997;133:8-18.)
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Intracardiac echocardiography during radiofrequency catheter ablation of cardiac arrhythmias in humans
Journal of the American College of Cardiology, 1994Co-Authors: Jonathan M Kalman, Michael Kwasman, Peter J Fitzgerald, Laurence M Epstein, Nelson B Schiller, Paul G Yock, Michael D LeshAbstract:OBJECTIVES: The purpose of this study was to describe our preliminary experience using catheter-based Intracardiac echocardiography as an adjunct to biplane fluoroscopy for guiding radiofrequency catheter ablation of atrial arrhythmias in the right side of the heart. BACKGROUND: Catheter ablation requires precise positioning and stable ablation electrode-endocardial contact. This procedure is currently guided by an analysis of Intracardiac electrograms and fluoroscopy. However, the use of fluoroscopy does not allow the endocardium and certain anatomic landmarks to be identified and is associated with the hazards of radiation exposure. METHODS: Seventeen symptomatic patients were studied. A 10F 10-MHz Intracardiac imaging catheter was used to visualize specific anatomic landmarks in the right atrium for directing the ablation electrode in 15 patients undergoing radiofrequency ablation of 19 arrhythmias and to assist with interatrial septal puncture in 3 patients. RESULTS: Continuous Intracardiac imaging was performed for a mean +/- SD of 63.6 +/- 39.2 min and demonstrated distal electrode-endocardial tissue contact in 81 (60%) of 134 radiofrequency applications. Movement of the catheter was demonstrated during 36 (44%), microcavitations during 39 (48%) and thrombus during 15 (19%) of the 81 imaged applications. In 7 of 10 procedures for atrial flutter, successful ablation was directed at anatomic corridors in the right atrium visualized with Intracardiac echocardiography. During ablation of atrial tachycardia, imaging identified abnormal atrial anatomy related to previous surgery and guided successful ablation of a reentrant tachycardia circulating around these anatomic obstacles. In two procedures for slow pathway modification of atrioventricular node reentrant tachycardia, Intracardiac echocardiography confirmed catheter stability at the tricuspid annulus anterior to the coronary sinus. CONCLUSIONS: During catheter ablation, Intracardiac echocardiography augments fluoroscopy by visualizing anatomic landmarks, ensuring stable endocardial contact and assisting in transseptal puncture. Ablation of typical atrial flutter can be successfully directed at anatomic corridors identified using Intracardiac imaging.
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radiofrequency catheter ablation guided by Intracardiac echocardiography
Circulation, 1994Co-Authors: Adam P Fitzpatrick, Paul G Yock, Michael C Chin, Krishnankutty Sudhir, Michael D LeshAbstract:BACKGROUND: Radiofrequency catheter ablation requires precise positioning of the ablation electrode. Fluoroscopically guided catheter manipulation has limitations, and there are risks of radiation exposure. The purpose of this study was to examine the feasibility of guiding catheter ablation within the right atrium with catheter-based Intracardiac echocardiography. METHODS AND RESULTS: A 10F, 10-MHz Intracardiac imaging catheter was used to direct an ablation electrode at four or five anatomic landmarks in the right atrium. Thirty-eight radiofrequency energy applications were performed in nine anesthetized dogs, and 38 lesions were identified on pathological examination. Lesions were created a mean of 1.9 +/- 2.1 mm from the ultrasound-guided site. Twenty-six of 38 lesions (68%) were less than 2.2 mm from the imaged site. Intracardiac echocardiography also was used to confirm stable electrode-endocardial contact in 37 energy applications (97%) and identified catheter movement in 9 energy applications (24%). Discrete lesions, microcavitations, and thrombi were observed in 13 (34%), 23 (61%), and 19 (50%) of 38 energy applications, respectively. Microcavitations predicted the appearance of thrombus. Fluoroscopy time required to create four or five lesions decreased from 23 minutes in the first study to less than 2 minutes in the last five studies. CONCLUSIONS: Catheter-based Intracardiac echocardiography can accurately guide catheter ablation directed at anatomic landmarks and potentially reduced ionizing radiation exposure. Intracardiac imaging can be used to confirm endocardial contact, identify electrode movement, and directly visualize lesions. Intracardiac echocardiography also can be used to identify microcavitations, which predict thrombus formation during radiofrequency energy applications.
Ziyad M Hijazi - One of the best experts on this subject based on the ideXlab platform.
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Intracardiac echocardiography in structural heart disease interventions
Jacc-cardiovascular Interventions, 2018Co-Authors: Mohamad Alkhouli, Ziyad M Hijazi, David R Holmes, Charanjit S Rihal, Susan E WiegersAbstract:Abstract Intracardiac echocardiography has historically been used to guide a limited number of transcatheter cardiac interventions. However, the tremendous advances in structural heart disease interventions in the last decade led to a growing interest in Intracardiac echocardiography as a potential alternative to transesophageal echocardiography that mitigates the need for endotracheal intubation. Nonetheless, the scarcity of data, the imperfection of the current probes, and the limited experience among operators prevented a wider adoption of this technology. This review summarizes the contemporary relevant evidence and provides the structural interventionalist with an illustrative guide on the use of Intracardiac echocardiography to guide various structural heart interventions.
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the use of Intracardiac echocardiography and other Intracardiac imaging tools to guide noncoronary cardiac interventions
Journal of the American College of Cardiology, 2009Co-Authors: Ziyad M Hijazi, Roberto M Lang, Bradley P. KnightAbstract:The limitations of standard fluoroscopy have led to the development of improved imaging techniques to guide noncoronary cardiac interventions. Imaging tools that are used in the interventional laboratory can be categorized as invasive and noninvasive. Noninvasive cardiac imaging tools include ultrasound, computed tomography, and magnetic resonance imaging. These modalities can generate high-resolution images of the heart and are increasingly being used to guide cardiac interventions. Despite these advances, there remains a strong role for invasive imaging tools in the interventional laboratories. Such invasive imaging tools include transesophageal echocardiography, Intracardiac echocardiography, Intracardiac endoscopy, and electroanatomic mapping systems. Despite the risks inherent to the invasive nature of these tools, these modalities can provide excellent real-time, detailed images that can be invaluable in guiding certain cardiac interventions. This review will propose the features of an ideal Intracardiac imaging tool, summarize the Intracardiac imaging tools that are currently available or under development to guide noncoronary cardiac interventional procedures, and suggest opportunities for improvement. One opportunity in this field is to couple imaging systems directly with the interventional devices themselves. The use of Intracardiac imaging to guide select cardiac procedures including transseptal catheterization, catheter ablation procedures for arrhythmias, and percutaneous placement of cardiac valves and closure devices will also be discussed. Most of this review will be devoted to Intracardiac echocardiography, which currently has the broadest number of applications.
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The Use of Intracardiac Echocardiography and Other Intracardiac Imaging Tools to Guide Noncoronary Cardiac Interventions
Journal of the American College of Cardiology, 2009Co-Authors: Susan S. Kim, Ziyad M Hijazi, Roberto M Lang, Bradley P. KnightAbstract:The limitations of standard fluoroscopy have led to the development of improved imaging techniques to guide noncoronary cardiac interventions. Imaging tools that are used in the interventional laboratory can be categorized as invasive and noninvasive. Noninvasive cardiac imaging tools include ultrasound, computed tomography, and magnetic resonance imaging. These modalities can generate high-resolution images of the heart and are increasingly being used to guide cardiac interventions. Despite these advances, there remains a strong role for invasive imaging tools in the interventional laboratories. Such invasive imaging tools include transesophageal echocardiography, Intracardiac echocardiography, Intracardiac endoscopy, and electroanatomic mapping systems. Despite the risks inherent to the invasive nature of these tools, these modalities can provide excellent real-time, detailed images that can be invaluable in guiding certain cardiac interventions. This review will propose the features of an ideal Intracardiac imaging tool, summarize the Intracardiac imaging tools that are currently available or under development to guide noncoronary cardiac interventional procedures, and suggest opportunities for improvement. One opportunity in this field is to couple imaging systems directly with the interventional devices themselves. The use of Intracardiac imaging to guide select cardiac procedures including transseptal catheterization, catheter ablation procedures for arrhythmias, and percutaneous placement of cardiac valves and closure devices will also be discussed. Most of this review will be devoted to Intracardiac echocardiography, which currently has the broadest number of applications. © 2009 American College of Cardiology Foundation.
Roberto M Lang - One of the best experts on this subject based on the ideXlab platform.
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the use of Intracardiac echocardiography and other Intracardiac imaging tools to guide noncoronary cardiac interventions
Journal of the American College of Cardiology, 2009Co-Authors: Ziyad M Hijazi, Roberto M Lang, Bradley P. KnightAbstract:The limitations of standard fluoroscopy have led to the development of improved imaging techniques to guide noncoronary cardiac interventions. Imaging tools that are used in the interventional laboratory can be categorized as invasive and noninvasive. Noninvasive cardiac imaging tools include ultrasound, computed tomography, and magnetic resonance imaging. These modalities can generate high-resolution images of the heart and are increasingly being used to guide cardiac interventions. Despite these advances, there remains a strong role for invasive imaging tools in the interventional laboratories. Such invasive imaging tools include transesophageal echocardiography, Intracardiac echocardiography, Intracardiac endoscopy, and electroanatomic mapping systems. Despite the risks inherent to the invasive nature of these tools, these modalities can provide excellent real-time, detailed images that can be invaluable in guiding certain cardiac interventions. This review will propose the features of an ideal Intracardiac imaging tool, summarize the Intracardiac imaging tools that are currently available or under development to guide noncoronary cardiac interventional procedures, and suggest opportunities for improvement. One opportunity in this field is to couple imaging systems directly with the interventional devices themselves. The use of Intracardiac imaging to guide select cardiac procedures including transseptal catheterization, catheter ablation procedures for arrhythmias, and percutaneous placement of cardiac valves and closure devices will also be discussed. Most of this review will be devoted to Intracardiac echocardiography, which currently has the broadest number of applications.
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The Use of Intracardiac Echocardiography and Other Intracardiac Imaging Tools to Guide Noncoronary Cardiac Interventions
Journal of the American College of Cardiology, 2009Co-Authors: Susan S. Kim, Ziyad M Hijazi, Roberto M Lang, Bradley P. KnightAbstract:The limitations of standard fluoroscopy have led to the development of improved imaging techniques to guide noncoronary cardiac interventions. Imaging tools that are used in the interventional laboratory can be categorized as invasive and noninvasive. Noninvasive cardiac imaging tools include ultrasound, computed tomography, and magnetic resonance imaging. These modalities can generate high-resolution images of the heart and are increasingly being used to guide cardiac interventions. Despite these advances, there remains a strong role for invasive imaging tools in the interventional laboratories. Such invasive imaging tools include transesophageal echocardiography, Intracardiac echocardiography, Intracardiac endoscopy, and electroanatomic mapping systems. Despite the risks inherent to the invasive nature of these tools, these modalities can provide excellent real-time, detailed images that can be invaluable in guiding certain cardiac interventions. This review will propose the features of an ideal Intracardiac imaging tool, summarize the Intracardiac imaging tools that are currently available or under development to guide noncoronary cardiac interventional procedures, and suggest opportunities for improvement. One opportunity in this field is to couple imaging systems directly with the interventional devices themselves. The use of Intracardiac imaging to guide select cardiac procedures including transseptal catheterization, catheter ablation procedures for arrhythmias, and percutaneous placement of cardiac valves and closure devices will also be discussed. Most of this review will be devoted to Intracardiac echocardiography, which currently has the broadest number of applications. © 2009 American College of Cardiology Foundation.
Allan S Jaffe - One of the best experts on this subject based on the ideXlab platform.
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Intracardiac thrombosis and anticoagulation therapy in cardiac amyloidosis
Circulation, 2009Co-Authors: Da Li Feng, Imran S Syed, Matthew W Martinez, Jae K Oh, Allan S Jaffe, Martha Grogan, William D Edwards, Morie A Gertz, Kyle W KlarichAbstract:Background— Primary amyloidosis has a poor prognosis as a result of frequent cardiac involvement. We recently reported a high prevalence of Intracardiac thrombus in cardiac amyloid patients at autopsy. However, neither the prevalence nor the effect of anticoagulation on Intracardiac thrombus has been evaluated antemortem. Methods and Results— We studied all transthoracic and transesophageal echocardiograms of cardiac amyloid patients at the Mayo Clinic. The prevalence of Intracardiac thrombosis, clinical and transthoracic/transesophageal echocardiographic risks for Intracardiac thrombosis, and effect of anticoagulation were investigated. We identified 156 patients with cardiac amyloidosis who underwent transesophageal echocardiograms. Amyloidosis was the primary type (AL) in 80; other types occurred in 76 patients, including 56 with the wild transthyretin type, 17 with the mutant transthyretin type, and 3 with the secondary type. Fifth-eight Intracardiac thrombi were identified in 42 patients (27%). AL am...
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Intracardiac thrombosis and embolism in patients with cardiac amyloidosis
Circulation, 2007Co-Authors: Da Li Feng, Matthew W Martinez, Jae K Oh, Martha Grogan, William D Edwards, Krishnaswamy Chandrasekaran, Imran Syed, Deborah A Hughes, John A Lust, Allan S JaffeAbstract:Background—Patients with primary amyloidosis (AL type) have a poor prognosis, in part due to frequent cardiac involvement. Although Intracardiac thrombus has been reported in anecdotal cases, neither its frequency nor its role in causing mortality is known. Furthermore, the clinical and echocardiographic variables that may be associated with thromboembolism in cardiac amyloidosis have not been defined. Methods and Results—A total of 116 autopsy or explanted cases of cardiac amyloidosis (55 AL and 61 other type) were identified in the Mayo Clinic. Forty-six fatal nonamyloid trauma cases served as controls. Each heart was examined for Intracardiac thrombus. The cause of death was determined from autopsy and clinical notes. Intracardiac thrombosis was identified in 38 hearts (33%). Twenty-three had 1 thrombus, whereas 15 had 2 to 5 thrombi. Although subjects in the AL group were younger and had less atrial fibrillation than those with other types of amyloidosis, the AL group had significantly more Intracardiac thrombus (51% versus 16%, P0.001) and more fatal embolic events (26% versus 8%, P0.03). Control hearts had no Intracardiac thrombus. The presence of both atrial fibrillation and AL was associated with an extremely high risk for thromboembolism (odds ratio 55.0 [95% confidence interval 8.1 to 1131.4]). By multivariate analysis, AL type (odds ratio 8.4 [95% confidence interval 1.8 to 51.2]) and left ventricular diastolic dysfunction (odds ratio 12.2 [95% confidence interval 2.7 to 72.7]) were independently associated with thromboembolism. Conclusions—A high frequency of Intracardiac thrombosis was present in cardiac amyloidosis. Furthermore, thromboembolism caused significant fatality. Several risk factors for thromboembolism were identified. Early screening, especially in high-risk patients, and early anticoagulation might reduce morbidity and mortality. (Circulation. 2007;116: 2420-2426.)
