Curr Cardiol Rep (2014) 16:511 DOI 10.1007/s11886-014-0511-6

INVASIVE ELECTROPHYSIOLOGY AND PACING (EK HEIST, SECTION EDITOR)

Catheter Ablation Guided by Real-Time MRI Charlotte Eitel & Gerhard Hindricks & Matthias Grothoff & Matthias Gutberlet & Philipp Sommer

Published online: 22 June 2014 # Springer Science+Business Media New York 2014

Abstract Real-time magnetic resonance imaging (MRI) combines the advantages of excellent soft-tissue characterization in a true 3D anatomical and functional model with the possibility of lesion and gap visualization without the need of any radiation. Therefore, real-time MRI presents a particularly attractive imaging technology to guide electrophysiology studies and catheter ablation procedures. This article aims to provide an overview on current routine clinical application of MRI in the setting of interventional electrophysiology. Furthermore, development of real-time MRI guided electrophysiology studies and first experiences with MRI guided catheter ablation procedures are depicted. In this context advantages, challenges and limitations of real-time MRI guided catheter ablation as well as future perspectives are discussed. Keywords Real-time MRI . CMR . Catheter ablation . Electrophysiology . Catheter tracking . MRI guided ablation

This article is part of the Topical Collection on Invasive Electrophysiology and Pacing C. Eitel (*) : G. Hindricks : P. Sommer Department of Electrophysiology, University of Leipzig, Heart Center, Struempellstrasse 39, 04289 Leipzig, Germany e-mail: [email protected] G. Hindricks e-mail: [email protected] P. Sommer e-mail: [email protected] M. Grothoff : M. Gutberlet Department of Diagnostic and Interventional Radiology, University of Leipzig, Heart Center, Leipzig, Germany M. Grothoff e-mail: [email protected] M. Gutberlet e-mail: [email protected]

Abbreviations AF Atrial fibrillation CS Coronary sinus DE Delayed enhancement LAO Left anterior oblique MRI Magnetic resonance imaging RAO Right anterior oblique

Introduction The number of catheter ablation procedures is growing steadily due to increasing knowledge of pathophysiological mechanisms of complex arrhythmias with the possibility of effective treatment [1]. Understanding and visualization of the underlying anatomical substrate is essential for the treatment of arrhythmias with a complex three-dimensional substrate [e.g., atrial fibrillation (AF), ventricular tachycardia (VT)]. Due to the limitations of 2D fluoroscopy to provide the required precision of 3D orientation, 3D mapping systems have been developed to facilitate accurate understanding of the individual anatomical and electrical substrate [2, 3]. Using these 3D mapping systems consequently did contribute to a significant reduction of fluoroscopy burden in complex ablation procedures and even allowed “zero-fluoroscopy” procedures in less complex ablations [4]. Besides these a novel sensor based 3D navigation system has been introduced recently, integrating 3D non-fluoroscopic catheter navigation on pre-recorded cine-loops (MediGuide Technology) [5]. However, all these technologies are limited by inaccuracies in image acquisition and registration and still require usage of fluoroscopy [6]. In this setting, real-time magnetic resonance imaging (MRI) presents a particularly attractive imaging technology to guide electrophysiology studies and catheter ablation

511, Page 2 of 7

procedures. Benefits relate to (1) the fluoroscopy-free environment, (2) substrate analysis, (3) combination of 3D anatomical and functional information, as well as (4) real-time visualization of ablation lesions and introduced catheters. This article aims to provide an overview on current routine clinical applications of MRI in the setting of interventional electrophysiology. Furthermore, development of real-time MRI guided electrophysiology studies and first experiences with MRI guided catheter ablation procedures are depicted. In this context advantages, challenges and limitations of realtime MRI guided catheter ablation as well as future perspectives are discussed.

Peri-procedural use of MRI in the Context of Catheter Ablation Catheter Ablation of Ventricular Tachycardia Delayed enhancement (DE) MRI is the gold standard for delineation of scar/fibrosis and facilitates precise detection of amount and extent of scar that serves as an arrhythmogenic substrate in patients with VT [7, 8]. Therefore, pre-procedural MRI in the setting of VT ablation is increasingly performed to gain more insights regarding the underlying substrate. Techniques have been developed not only to integrate a preacquired anatomical surface model, but also to integrate disease causing scar volumes in the setting of VT ablation [9•]. In this study MRI even facilitated identification of nontransmural scars and infarct grey zones not detected by electroanatomical voltage mapping potentially providing important supplementary substrate information in patients with ischemic cardiomyopathy [9•]. Patients with non-ischemic cardiomyopathy usually exhibit a more complicated morphology and distribution pattern of VT substrate compared to ischemic cardiomyopathy [10]. Characterization of the nonischemic VT substrate in these patients by DE-MRI may lead to optimization of electrogram thresholds for identification of midwall and epicardial scar and enable pre-procedural planning for epicardial access [11, 12]. Despite the benefits of pre-procedural MRI for substrate characterization, the majority of patients referred for VT ablation have an implanted device which is considered a contraindication for performing MRI [13]. However, recent studies indicate the safety and feasibility of performing contrastenhanced cardiac MRI in selected patients with ICDs with the aim of integrating detailed 3D scar maps into clinical mapping systems [14, 15]. This is particularly important as ICD indications are expanding and an increasing number of patients undergoing VT ablation presents with recurrent ICD shocks [14].

Curr Cardiol Rep (2014) 16:511

Catheter Ablation of Atrial Fibrillation In AF patients DE-MRI has been shown to serve as a valuable noninvasive imaging method to assess and quantify the extent of left atrial fibrosis as an indicator of structural remodeling [16]. Consequently higher degrees of fibrosis have been introduced as an independent predictor of AF ablation failure [17, 18••]. Results of the multicenter Delayed Enhancement MRI determinant of successful Catheter Ablation of Atrial Fibrillation (DECAAF) - trial (NCT01150214) confirm that stage of atrial fibrosis assessed by MRI prior to ablation serves as an independent predictor of outcome [19••]. In this way pre-ablation knowledge of the arrhythmogenic substrate might result in avoidance of ablation in patients with very low probability of success on the one hand and individualized treatment concepts with targeted ablation of fibrotic tissue on the other hand. However, this approach still needs to be proven in other well designed studies. Besides performance of DE-MRI for quantification of left atrial fibrosis prior to AF ablation, T1 mapping has been introduced as a new methodology to quantify diffuse fibrotic changes in thin-walled myocardial tissues like the left atrium [20•]. Potential advantages of T1-mapping relate to the lacking dependence of the correct inversion time and the largely automated measurement [20•]. The value of this methodology in the context of catheter ablation procedures still needs to be proven. A recent study indicates that quantification of extracellular volume with the use of T1 measurements facilitates prediction of recurrent AF post–pulmonary vein isolation [21]. Catheter ablation of complex atrial arrhythmias requires accurate knowledge of the true cardiac anatomy of the respective patient, especially in the setting of anatomically defined lesion sets such as in pulmonary vein isolation that still presents the cornerstone of AF ablation. Pulmonary vein anatomy has been described to vary in up to 38 % of patients presenting for AF ablation [22]. This is of interest as additional veins might serve as triggers and as inadvertent delivery of ablation lesions inside a pulmonary vein might increase the risk of subsequent stenosis [23]. Therefore pre-procedural assessment of computed tomography or MRI images of the left atrium is routinely performed in most centers for integration with electroanatomic maps as this facilitates better understanding of the underlying individual 3D anatomy. Post-interventionally, MRI is a very useful tool for detection of complications, like pulmonary vein stenosis following AF ablation. Additionally esophageal injury may be detected and monitored with the use of DE-MRI [24]. Lesion Visualization A unique feature of MRI presents the possibility of imaging deployed lesion sets and remaining gaps [25–29]. Initial

Curr Cardiol Rep (2014) 16:511

studies demonstrated the possibility of visualizing spatial and temporal extent of ventricular ablation lesions and correlation with histopathological specimens in dogs [27, 29]. The role of DE-MRI in detecting and quantifying left atrial wall injury after pulmonary vein isolation and correlation with ablation outcome at 3 months has been shown recently [25, 26, 30, 31]. This might facilitate prediction of prognosis and planning of repeat procedures with targeted closure of lesion gaps in AF patients [25, 26, 31]. Despite adequate assessment of radiofrequency lesion size, transmural extent, and interlesional gaps throughout the different stages of gadolinium enhancement [27], the use of this technique for serial lesion assessment during a procedure is limited due to the time interval of about an hour required for renal clearance between repeated dosing of gadolinium and the ceiling on total allowable gadolinium dose [32, 33]. To overcome this limitation the feasibility to assess acute and subacute radiofrequency lesions with the use of noncontrast enhanced MRI has been described in animal studies [28, 34, 35•]. This may allow intraprocedural evaluation of radiofrequency lesions in the human heart.

Catheter Ablation Guided by Real-time MRI Potential Advantages of Catheter Ablation Guided by Real-time MRI Besides a reduction or even elimination of fluoroscopy, significant advantages of performing catheter ablation directly in the MR scanner relate to true anatomical real-time 3D visualization not only of the underlying anatomy, substrate and neighboring structures, but also of the exact catheter position in relation to these. Another unique feature of real-time MRI in the electrophysiology setting constitutes the immediate detection of lesions and even gaps in ablation lines [25–29, 34]. This might facilitate individualized ablation strategies with preablation planning of the interventional approach, specific targeting of the individual underlying arrhythmogenic substrate or of remaining gaps in previously placed ablation lines. Furthermore, MR thermography offers the possibility to noninvasively image tissue heating potentially facilitating accurate noninvasive prediction of tissue destruction during RF ablation procedures as well as prevention of damaging neighboring structures with esophageal fistulas presenting the most fatal form [36]. Challenges of Catheter Ablation Guided by Real-Time MRI Despite all these promises the clinical application of real-time MRI is hampered by several challenges: First of all the electrophysiologist is facing a completely different setup. Communication between the operator, the nurse and the out-side

Page 3 of 7, 511

team members, which adjust the scanning planes and manage the electrophysiology system has to be established using wireless headsets in order to overcome the noise being made by the MR scanner. Electrocardiogram and oxygen saturation monitoring requires MR compatible equipment, and perfusion lines connected to monitors containing ferromagnetic material have to be introduced from outside the MR suite. Furthermore until now no acute defibrillation or cardioversion can be performed in the MR scanner. Electrophysiology catheters and devices usually contain metallic materials and are not approved for use in the MRI. Therefore special MR conditional devices and catheters consisting of MR-safe non-ferromagnetic components to reduce MR-induced heating, electrical noise and imaging artifacts have been designed. Development of MR compatible open-irrigated ablation catheters was a prerequisite to achieve adequate lesion depth and improve safety profile in complex ablation procedures [37, 38, 39•, 40•]. Additionally, filters have been introduced for noise suppression and enhancement of small intracardiac electrograms [37, 40•]. Quality of QRS morphology and surface ECG are still hampered, but timing of QRS complexes can be identified quite reliably. Besides 3D imaging of complex cardiovascular anatomy, real-time MRI offers the possibility of 2D imaging along arbitrary imaging planes. From an electrophysiology perspective this means, that reorientation is needed with respect to familiar planes, as fluoroscopy provides summation images of the whole catheter and orientation during electrophysiology procedures is routinely performed within right anterior (RAO) and left anterior oblique (LAO) views. In the setting of passive catheter tracking (catheters that are visualized by metallic artifacts) [41] an approach of sequential imaging of the catheter in two corresponding orthogonal planes - comparable to fluoroscopic RAO and LAO projections proved helpful for guiding catheter ablation [42•]. However, active catheter tracking (MRI signal received by the catheter) [43] is desirable as it might be easier to localize the respective catheters potentially leading to improved procedure safety, shorter procedure times and higher success rates [44]. Further developments aim at improving guidance of active catheters with the use of automatic tip alignment algorithms [44]. Animal Studies Lardo et al. for the first time demonstrated the feasibility of performing real-time MRI guided electrophysiology studies in 6 dogs [29]. Nonmagnetic catheters could be successfully placed at right atrial and ventricular targets, intracardiac electrograms could be recorded and placed ablation lesions were visualized [29]. Subsequently, Nazarian and colleagues performed comprehensive electrophysiology studies with placement of catheters at the right atrial, His bundle

511, Page 4 of 7

Curr Cardiol Rep (2014) 16:511

and right ventricular targets, recording of intracardiac signals and performance of atrial and ventricular pacing maneuvers [44]. Instead of passive catheter tracking, further studies developed magnetic resonance based catheter tracking that could be successfully used for performing electroanatomic mapping and radiofrequency ablation of the pulmonary veins and AV node in the MRI environment [45, 46]. Advancements have been made with respect to development of MR-conditional catheters and electrophysiology equipment which were successfully employed for real-time guidance of atrial and ventricular radiofrequency ablation procedures including atrioventricular node modulation [47], isthmus ablation [48], ablation of gaps in previously applied lesions in the right atrium [49] and also biatrial ablation including pulmonary vein ablation [38]. Just recently our group could show the feasibility of MRI guided active catheter tracking for real-time intracardiac navigation, biatrial electroanatomic mapping and atrioventricular node ablation [39•]. Active catheter tracking was performed using the magnetic field to localize inductive coils assembled on the electrophysiology catheter and autosegmentation algorithms created auto-registered 3D models of all cardiac chambers [39•]. The coils were then shown as a virtual catheter icon displayed in real-time in the autosegmented/auto-registered 3D model, in the pre-acquired

MRI planes (Fig. 1), and during further scanning [39•]. Furthermore, electroanatomical mapping can be performed (Fig. 2).

Fig. 1 Active catheter tracking in a pig using the Philips iSuite® platform. The green catheter tip is located in the coronary sinus (CS) and the red catheter tip is located in the right ventricular outflow tract. Catheter

location is shown in three different orthogonal planes (a-c) and in a 3Dshell reconstruction that was built from a pre-recorded 3D-whole-heart data set (d)

Human Studies Limited electrophysiology studies in two humans with targeted guidance of one catheter and confirmation via recording of intracardiac electrograms under guidance of real-time MRI have first been performed by Nazarian et al. [44]. Our group showed for the first time the feasibility and safety of performing diagnostic electrophysiology studies with the usage of multiple MR conditional catheters in humans [37, 40•]. Finally, the first successful real-time MRI guided ablation of the cavotricuspid isthmus could be performed [42•]. A total of ten patients underwent ablation of the cavotricuspid isthmus in a standard 1.5T MRI scanner with a standard real-time SSFP sequence using passive catheter tracking [50]. The feasibility and safety of recording intracardiac electrograms and placement of ablation lesions could be shown. However, in nine of ten patients additional fluoroscopy guided placement of ablation lesions had to be performed in the electrophysiology lab due to incomplete isthmus block. The main reason for this might have been difficult handling of the ablation catheter and a predefined limited time of 90 minutes in the MRI scanner

Curr Cardiol Rep (2014) 16:511

Page 5 of 7, 511

Fig. 2 Electroanatomical mapping with active catheter tracking in the right ventricle and right atrium of a pig using the Philips iSuite® platform. Orthogonal planes (a, b) showing the catheter tip (red), green dots representing mapping points (LAT map, precocity of electrograms, c) in a 3D map (d). In c, surface ECG (green) and electrograms from 2 MRI

enabled catheters (white tracing=mapping catheter in RA; yellow tracing=diagnostic catheter in CS, serving as reference signal for the map) are shown. In the lower panel (c) the reference marker is adjusted on CS signal for LAT mapping

due to safety reasons. Visualization and MRI guided passive tracking of the inserted catheters using real time SSFP imaging was feasible in all patients [50].

important feature for the patient, the interventional electrophysiologist and the nurses.

Conclusions Future Perspective Based on current progress in the field of interventional MRI an increasing number of ablation procedures will target the underlying arrhythmogenic substrate leading to individualized ablation concepts. Besides this, preprocedural MRI serves as a risk stratifying tool enabling identification of patients who will benefit most from a particular procedure or in whom risks outweigh potential benefits. Technical developments aim on further improvement of active catheter tracking algorithms as well as automated integration of mapping and scanning information. Besides this integration of data on tissue feedback and thermometry might lead to more efficient lesion creation potentially leading to higher success and lower complication rates. In the light of a growing amount of ablation procedures the fact that real-time MRI guided procedures will be performed without the use of any radiation presents a unique and

Real-time MRI combines the advantages of excellent soft-tissue characterization in a true 3D anatomical and functional model with the possibility of lesion and gap visualization without the need of any radiation. The safety and feasibility of real-time MRI guided electrophysiology studies [37, 40•, 44] and first ablation procedures [39•, 42•, 51] in humans have been described recently. Until now, these experiences are limited to few centers and widespread application is still impaired due to the above mentioned challenges but developments are under way moving this promising technology closer to routine clinical application. Compliance with Ethics Guidelines Conflict of Interest Charlotte Eitel reports received modest lecture honoraria from Philips GmbH, UB Healthcare, personal fees from St. Jude Medical. Gerhard Hindricks received modest lecture honoraria from St. Jude Medical, Biotronik, Medtronic and Biosense and is a member of the St. Jude Medical and Biosense advisory boards.

511, Page 6 of 7 Matthias Grothoff received modest lecture honoraria from Philips and Siemens Healthcare. Matthias Gutberlet received modest lecture honoraria from Philips and Siemens Healthcare, and is a member of the Siemens MR advisory board. Philipp Sommer received modest lecture honoraria by St Jude Medical, and Siemens Healthcare, and is a member of the St. Jude Medical advisory board. Human and Animal Rights and Informed Consent This article does not contain any studies with human or animal subjects performed by any of the authors.

References Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance 1.

Tracy CM, Akhtar M, DiMarco JP, Packer DL, Weitz HH, Creager MA, et al. American College of Cardiology/American Heart Association 2006 update of the clinical competence statement on invasive electrophysiology studies, catheter ablation, and cardioversion: a report of the American College of Cardiology/American Heart Association/American College of Physicians Task Force on Clinical Competence and Training: developed in collaboration with the Heart Rhythm Society. Circulation. 2006;114:1654–68. 2. Ben-Haim SA, Osadchy D, Schuster I, Gepstein L, Hayam G, Josephson ME. Nonfluoroscopic, in vivo navigation and mapping technology. Nat Med. 1996;2:1393–5. 3. Wittkampf FH, Wever EF, Derksen R, Wilde AA, Ramanna H, Hauer RN, et al. LocaLisa: new technique for real-time 3dimensional localization of regular intracardiac electrodes. Circulation. 1999;99:1312–7. 4. Casella M, Pelargonio G, Dello Russo A, Riva S, Bartoletti S, Santangeli P, et al. "Near-zero" fluoroscopic exposure in supraventricular arrhythmia ablation using the ensite navx mapping system: Personal experience and review of the literature. J Interv Card Electrophysiol. 2011;31:109–118. 5. Rolf S, Sommer P, Gaspar T, John S, Arya A, Hindricks G, et al. Ablation of atrial fibrillation using novel 4-dimensional catheter tracking within autoregistered left atrial angiograms. Circ Arrhythm Electrophysiol. 2012;5:684–90. 6. Eitel C, Piorkowski C, Gaspar T, Sommer P, Hindricks G. The future of fluoroless cardiovascular interventions. JAFIB. 2013;5: 76–9. 7. Kim RJ, Fieno DS, Parrish TB, Harris K, Chen EL, Simonetti O, et al. Relationship of MRI delayed contrast enhancement to irreversible injury, infarct age, and contractile function. Circulation. 1999;100:1992–2002. 8. Nazarian S, Bluemke DA, Lardo AC, Zviman MM, Watkins SP, Dickfeld TL, et al. Magnetic resonance assessment of the substrate for inducible ventricular tachycardia in nonischemic cardiomyopathy. Circulation. 2005;112:2821–5. 9.• Wijnmaalen AP, van der Geest RJ, van Huls van Taxis CF, Siebelink HM, Kroft LJ, Bax JJ, et al. Head-to-head comparison of contrast-enhanced magnetic resonance imaging and electroanatomical voltage mapping to assess post-infarct scar characteristics in patients with ventricular tachycardias: real-time image integration and reversed registration. Eur Heart J. 2011;32:104–14. This study describes feasibility and value of integrating MRI-

Curr Cardiol Rep (2014) 16:511 derived scar maps with electroanatomic voltage maps during VT ablation. 10. Karamitsos TD, Francis JM, Myerson S, Selvanayagam JB, Neubauer S. The role of cardiovascular magnetic resonance imaging in heart failure. J Am Coll Cardiol. 2009;54:1407–24. 11. Piers SR, Tao Q, van Huls van Taxis CF, Schalij MJ, van der Geest RJ, Zeppenfeld K. Contrast-enhanced MRI-derived scar patterns and associated ventricular tachycardias in nonischemic cardiomyopathy: implications for the ablation strategy. Circ Arrhythm Electrophysiol. 2013;6:875–83. 12. Sasaki T, Miller CF, Hansford R, Zipunnikov V, Zviman MM, Marine JE, Spragg D, Cheng A, Tandri H, Sinha S, Kolandaivelu A, Zimmerman SL, Bluemke DA, Tomaselli GF, Berger RD, Halperin HR, Calkins H, Nazarian S. Impact of nonischemic scar features on local ventricular electrograms and scar-related ventricular tachycardia circuits in patients with nonischemic cardiomyopathy. Circ Arrhythm Electrophysiol. 2013. 13. Faris OP, Shein M. Food and Drug Administration perspective: magnetic resonance imaging of pacemaker and implantable cardioverter-defibrillator patients. Circulation. 2006;114:1232–3. 14. Dickfeld T, Tian J, Ahmad G, Jimenez A, Turgeman A, Kuk R, et al. MRI-Guided ventricular tachycardia ablation: integration of late gadolinium-enhanced 3D scar in patients with implantable cardioverter-defibrillators. Circ Arrhythm Electrophysiol. 2011;4: 172–84. 15. Stevens SM, Tung R, Rashid S, Gima J, Cote S, Pavez G, Khan S, Ennis DB, Paul FJ, Boyle N, Shivkumar K, Hu P. Device artifact reduction for magnetic resonance imaging of patients with implantable cardioverter-defibrillators and ventricular tachycardia: Late gadolinium enhancement correlation with electroanatomic mapping. Heart Rhythm. 2013. 16. Oakes RS, Badger TJ, Kholmovski EG, Akoum N, Burgon NS, Fish EN, et al. Detection and quantification of left atrial structural remodeling with delayed-enhancement magnetic resonance imaging in patients with atrial fibrillation. Circulation. 2009;119:1758– 67. 17. Mahnkopf C, Badger TJ, Burgon NS, Daccarett M, Haslam TS, Badger CT, et al. Evaluation of the left atrial substrate in patients with lone atrial fibrillation using delayed-enhanced MRI: implications for disease progression and response to catheter ablation. Heart Rhythm. 2010;7:1475–81. 18.•• McGann C, Akoum N, Patel A, Kholmovski E, Revelo P, Damal K, et al. Atrial fibrillation ablation outcome is predicted by left atrial remodeling on MRI. Circ Arrhythm Electrophysiol. 2013. doi:10. 1161/CIRCEP.113.000689. This study again confirms the value of contrast enhanced MRI for noninvasive assessment of left atrial fibrosis and correlation with AF ablation outcome. 19.•• Marrouche NF, Wilber D, Hindricks G, Jais P, Akoum N, Marchlinski F, et al. Association of atrial tissue fibrosis identified by delayed enhancement MRI and atrial fibrillation catheter ablation: the DECAAF study. JAMA. 2014;31((5):498–506. This is the first multicenter, prospective, observational cohort study describing an independent association of atrial tissue fibrosis estimated by delayed enhancement MRI with likelihood of recurrent arrhythmia following catheter ablation of atrial fibrillation. 20.• Beinart R, Khurram IM, Liu S, Yarmohammadi H, Halperin HR, Bluemke DA, et al. Cardiac magnetic resonance T1 mapping of left atrial myocardium. Heart Rhythm. 2013;10:1325–31. In this study for the first time the usefulness of T1 mapping for detection of left atrial fibrosis is described. 21. Neilan TG, Mongeon FP, Shah RV, Coelho-Filho O, Abbasi SA, Dodson JA, et al. Myocardial extracellular volume expansion and the risk of recurrent atrial fibrillation after pulmonary vein isolation. JACC Cardiovasc Imaging. 2014;7:1–11. 22. Kato R, Lickfett L, Meininger G, Dickfeld T, Wu R, Juang G, et al. Pulmonary vein anatomy in patients undergoing catheter ablation of

Curr Cardiol Rep (2014) 16:511 atrial fibrillation: lessons learned by use of magnetic resonance imaging. Circulation. 2003;107:2004–10. 23. Mansour M, Refaat M, Heist EK, Mela T, Cury R, Holmvang G, et al. Three-dimensional anatomy of the left atrium by magnetic resonance angiography: implications for catheter ablation for atrial fibrillation. J Cardiovasc Electrophysiol. 2006;17:719–23. 24. Badger TJ, Adjei-Poku YA, Burgon NS, Kalvaitis S, Shaaban A, Sommers DN, et al. Initial experience of assessing esophageal tissue injury and recovery using delayed-enhancement MRI after atrial fibrillation ablation. Circ Arrhythm Electrophysiol. 2009;2: 620–5. 25. Badger TJ, Daccarett M, Akoum NW, Adjei-Poku YA, Burgon NS, Haslam TS, et al. Evaluation of left atrial lesions after initial and repeat atrial fibrillation ablation: lessons learned from delayedenhancement MRI in repeat ablation procedures. Circ Arrhythm Electrophysiol. 2010;3:249–59. 26. McGann C, Kholmovski E, Blauer J, Vijayakumar S, Haslam T, Cates J, et al. Dark regions of no-reflow on late gadolinium enhancement magnetic resonance imaging result in scar formation after atrial fibrillation ablation. J Am Coll Cardiol. 2011;58:177–85. 27. Dickfeld T, Kato R, Zviman M, Lai S, Meininger G, Lardo AC, et al. Characterization of radiofrequency ablation lesions with gadolinium-enhanced cardiovascular magnetic resonance imaging. J Am Coll Cardiol. 2006;47:370–8. 28. Dickfeld T, Kato R, Zviman M, Nazarian S, Dong J, Ashikaga H, et al. Characterization of acute and subacute radiofrequency ablation lesions with nonenhanced magnetic resonance imaging. Heart Rhythm. 2007;4:208–14. 29. Lardo AC, McVeigh ER, Jumrussirikul P, Berger RD, Calkins H, Lima J, et al. Visualization and temporal/spatial characterization of cardiac radiofrequency ablation lesions using magnetic resonance imaging. Circulation. 2000;102:698–705. 30. Badger TJ, Oakes RS, Daccarett M, Burgon NS, Akoum N, Fish EN, et al. Temporal left atrial lesion formation after ablation of atrial fibrillation. Heart Rhythm. 2009;6:161–8. 31. McGann CJ, Kholmovski EG, Oakes RS, Blauer JJ, Daccarett M, Segerson N, et al. New magnetic resonance imaging-based method for defining the extent of left atrial wall injury after the ablation of atrial fibrillation. J Am Coll Cardiol. 2008;52:1263–71. 32. Kolandaivelu A, Lardo AC, Halperin HR. Cardiovascular magnetic resonance guided electrophysiology studies. J Cardiovasc Magn Reson. 2009;11:21. 33. Schmidt EJ, Reddy VK, Ruskin JN. Nonenhanced magnetic resonance imaging for characterization of acute and subacute radiofrequency ablation lesions. Heart Rhythm. 2007;4:215–7. 34. Vergara GR, Vijayakumar S, Kholmovski EG, Blauer JJ, Guttman MA, Gloschat C, et al. Real-time magnetic resonance imagingguided radiofrequency atrial ablation and visualization of lesion formation at 3 Tesla. Heart Rhythm. 2011;8:295–303. 35.• Nordbeck P, Hiller KH, Fidler F, Warmuth M, Burkard N, Nahrendorf M, et al. Feasibility of contrast-enhanced and nonenhanced MRI for intraprocedural and postprocedural lesion visualization in interventional electrophysiology: animal studies and early delineation of isthmus ablation lesions in patients with typical atrial flutter. Circ Cardiovasc Imaging. 2011;4:282–94. This study evaluates contrast-enhanced and nonenhanced MRI for intraprocedural and postprocedural lesion visualization in animals and patients. 36. Kolandaivelu A, Zviman MM, Castro V, Lardo AC, Berger RD, Halperin HR. Noninvasive assessment of tissue heating during cardiac radiofrequency ablation using MRI thermography. Circ Arrhythm Electrophysiol. 2010;3:521–9. 37. Eitel C, Piork owski C, Hindricks G, Gutberlet M. Electrophysiology study guided by real-time magnetic resonance imaging. Eur Heart J. 2012;33:1975.

Page 7 of 7, 511 38.

39.•

40.•

41.

41.•

43.

44.

45.

46.

47.

48.

49.

50.

51.

Ganesan AN, Selvanayagam JB, Mahajan R, Grover S, Nayyar S, Brooks AG, et al. Mapping and ablation of the pulmonary veins and cavo-tricuspid isthmus with a magnetic resonance imagingcompatible externally irrigated ablation catheter and integrated electrophysiology system. Circ Arrhythm Electrophysiol. 2012;5: 1136–42. Gaspar T, Piorkowski C, Gutberlet M, Hindricks G. Threedimensional real-time MRI-guided intracardiac catheter navigation. Eur Heart J. 2013. doi:10.1093/eurheartj/eht327. In this case report the feasibility of MRI guided active catheter tracking for real-time intracardiac navigation, biatrial electroanatomic mapping and atrioventricular node ablation is evaluated in an animal model. Sommer P, Grothoff M, Eitel C, Gaspar T, Piorkowski C, Gutberlet M, et al. Feasibility of real-time magnetic resonance imaging-guided electrophysiology studies in humans. Europace. 2013;15:101–8. This case series summarizes the feasibility and challenges of performing EP studies under real-time MRI guidance in humans. Peeters JM, Seppenwoolde JH, Bartels LW, Bakker CJ. Development and testing of passive tracking markers for different field strengths and tracking speeds. Phys Med Biol. 2006;51: N127–37. Piorkowski C, Grothoff M, Gaspar T, Eitel C, Sommer P, Huo Y, et al. Cavotricuspid isthmus ablation guided by real-time magnetic resonance imaging. Circ Arrhythm Electrophysiol. 2013;6:e7–e10. This article for the first time describes successful performance of cavotricuspid isthmus ablation guided by real-time MRI in a human. Susil RC, Yeung CJ, Halperin HR, Lardo AC, Atalar E. Multifunctional interventional devices for MRI: a combined electrophysiology/MRI catheter. Magn Reson Med. 2002;47:594– 600. Nazarian S, Kolandaivelu A, Zviman MM, Meininger GR, Kato R, Susil RC, et al. Feasibility of real-time magnetic resonance imaging for catheter guidance in electrophysiology studies. Circulation. 2008;118:223–9. Dukkipati SR, Mallozzi R, Schmidt EJ, Holmvang G, d'Avila A, Guhde R, et al. Electroanatomic mapping of the left ventricle in a porcine model of chronic myocardial infarction with magnetic resonance-based catheter tracking. Circulation. 2008;118:853–62. Schmidt EJ, Mallozzi RP, Thiagalingam A, Holmvang G, d'Avila A, Guhde R, et al. Electroanatomic mapping and radiofrequency ablation of porcine left atria and atrioventricular nodes using magnetic resonance catheter tracking. Circ Arrhythm Electrophysiol. 2009;2:695–704. Nordbeck P, Bauer WR, Fidler F, Warmuth M, Hiller KH, Nahrendorf M, et al. Feasibility of real-time MRI with a novel carbon catheter for interventional electrophysiology. Circ Arrhythm Electrophysiol. 2009;2:258–67. Hoffmann BA, Koops A, Rostock T, Mullerleile K, Steven D, Karst R, et al. Interactive real-time mapping and catheter ablation of the cavotricuspid isthmus guided by magnetic resonance imaging in a porcine model. Eur Heart J. 2010;31:450–6. Ranjan R, Kholmovski EG, Blauer J, Vijayakumar S, Volland NA, Salama ME, et al. Identification and acute targeting of gaps in atrial ablation lesion sets using a real-time magnetic resonance imaging system. Circ Arrhythm Electrophysiol. 2012;5:1130–5. Grothoff M, Piorkowski C, Eitel C, Gaspar T, Hindricks G, Sommer P, et al. Magnetic resonance imaging guided electrophysiological ablation studies in humans using passive catheter tracking – initial results. Radiology. 2014;27:122671. doi:10.1148/radiol. 13122671. Nordbeck P, Beer M, Kostler H, Ladd ME, Quick HH, Bauer WR, et al. Cardiac catheter ablation under real-time magnetic resonance guidance. Eur Heart J. 2012;33:1977.

Catheter ablation guided by real-time MRI.

Real-time magnetic resonance imaging (MRI) combines the advantages of excellent soft-tissue characterization in a true 3D anatomical and functional mo...
533KB Sizes 1 Downloads 3 Views