Ebook Practical approach to catheter ablation of atrial fibrillation: Part 1

(BQ) Part 1 book Practical approach to catheter ablation of atrial fibrillation presents the following contents: Introduction and historical perspective, ablation program planning, mapping, imaging, and guidance systems.

GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page i Aptara Inc A Practical Approach to Catheter Ablation of Atrial Fibrillation GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page ii Aptara Inc GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page iii Aptara Inc A Practical Approach to Catheter Ablation of Atrial Fibrillation Editors HUGH CALKINS, MD Professor of Medicine Johns Hopkins University School of Medicine Director of the Arrhythmia Service and Clinical Electrophysiology Laboratory Johns Hopkins Hospital Baltimore, Maryland PIERRE JAÏS, MD Professor Department of Cardiology Université Victor Segalen–Bordeaux 2 Hôpital Cardiologique du Haut Lévèque Cardiology Department Bordeaux, France JONATHAN S STEINBERG, MD Chief, Division of Cardiology Endowed Director, Al-Sabah Arrhythmia Institute St Luke's and Roosevelt Hospitals New York, New York Director, Electrophysiology Valley Hospital Ridgewood, New Jersey Professor of Medicine Columbia University College of Physicians & Surgeons New York, New York GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page iv Aptara Inc Acquisitions Editor: Frances R DeStefano Managing Editor: Chris Potash Marketing Manager: Kimberly Schonberger Project Manager: Bridgett Dougherty Senior Manufacturing Manager: Benjamin Rivera Creative Director: Doug Smock Compositor: Aptara Inc © 2008 by LIPPINCOTT WILLIAMS & WILKINS All rights reserved This book is protected by copyright No part of this book may be reproduced in any form or by any means, including photocopying, or utilized by any information storage and retrieval system without written permission from the copyright owner, except for brief quotations embodied in critical articles and reviews Materials appearing in this book prepared by individuals as part of their official duties as U.S government employees are not covered by the abovementioned copyright Printed in the USA Library of Congress Cataloging-in-Publication Data A practical approach to catheter ablation of atrial fibrillation / editors, Hugh Calkins, Pierre Jaïs, Jonathan S Steinberg p ; cm ISBN-13: 978-0-7817-7559-5 (alk paper) ISBN-10: 0-7817-7559-0 (alk paper) 1 Catheter ablation 2 Atrial fibrillation—Surgery I Calkins, Hugh, 1956– II Jaïs, Pierre, 1964– III Steinberg, Jonathan S [DNLM: 1 Atrial Fibrillation—surgery 2 Catheter Ablation—methods WG 330 P8948 2008] RD598.35.C39P73 2008 617.4'120592—dc22 2008006111 Care has been taken to confirm the accuracy of the information presented and to describe generally accepted practices However, the authors, editors, and publisher are not responsible for errors or omissions or for any consequences from application of the information in this book and make no warranty, expressed or implied, with respect to the currency, completeness, or accuracy of the contents of the publication Application of this information in a particular situation remains the professional responsibility of the practitioner The authors, editors, and publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accordance with current recommendations and practice at the time of publication However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions This is particularly important when the recommended agent is a new or infrequently employed drug Some drugs and medical devices presented in this publication have Food and Drug Administration (FDA) clearance for limited use in restricted research settings It is the responsibility of the health care provider to ascertain the FDA status of each drug or device planned for use in their clinical practice 10 9 8 7 6 5 4 3 2 1 GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page v Aptara Inc To Alice, Rachel, and Josh, whose encouragement and support made all this effort possible —JS To Beth, Emily, Eliza, and Daniel —HC GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page vi Aptara Inc GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page vii Aptara Inc CONTENTS Contributing Authors xi Preface xxiii I Introduction and Historical Perspective 1 1 Indications for Atrial Fibrillation Ablation and Consensus Recommendations 3 Hugh Calkins 2 Nonpharmacological Therapy for Atrial Fibrillation: An Historical Overview 11 David A Spragg, Hugh Calkins II Ablation Program Planning 25 3 Equipment and Staffing 27 David Haines 4 Preprocedure Preparation 37 Jose F Huizar, Karoly Kaszala, Mark A Wood, Kenneth A Ellenbogen III Mapping, Imaging, and Guidance Systems 55 5 Intracardiac Ultrasound 57 Jonathan S Steinberg, Jayanthi Koneru, Kataneh Maleki, Farooq Chaudhry 6 Electroanatomic Mapping Systems 83 Anshul M Patel, Vivek Y Reddy 7 Magnetic and Robotic Navigation 100 Bruce D Lindsay, Mitchell Faddis 8 Noncontact Mapping 118 Satoshi Higa, Yenn-Jiang Lin, Ching-Tai Tai, Shih-Ann Chen vii GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page viii Aptara Inc viii Contents IV Ablation Procedures 135 9 Circumferential Ablation with PV Isolation Guided by Lasso Catheter 137 Feifan Ouyang, Kazuhiro Satomi, Karl-Heinz Kuck 10 Circumferential Atrial Ablation 167 Carlo Pappone, Vincenzo Santinelli 11 Electrogram-Guided Ablation 184 Evan Lockwood, Koonlawee Nademanee 12 Linear Left Atrial Ablation 198 Mélèze Hocini, Kang-Teng Lim, Prashanthan Sanders, Pierre Jaïs, Seiichiro Matsuo, Sébastien Knecht, Leonardo Arantès, Mark O’Neill, Yoshihide Takahashi, Jacques Clémenty, Michel Haïssaguerre 13 Tailored Approach to Ablation 210 Hakan Oral, Fred Morady 14 Ablation of Autonomic Ganglia 218 Hiroshi Nakagawa, Katsuaki Yokoyama, Benjamin Scherlag, Vikram Katari, Hiroshi Aoyama, Sara Foresti, Warren Jackman 15 Atrial Fibrillation Trigger Mapping 231 Francis Marchlinski, Fermin Garcia V Ablation Strategies 249 16 A Comprehensive Overview of Ablation of Paroxysmal, Persistent, and Permanent Atrial Fibrillation: A Stepwise Approach 251 Pierre Jaïs, Seiichiro Matsuo, Kang-Teng Lim, Mélèze Hocini, Sébastien Knecht, Leonardo Arantès, Pierre Bordachar, Jacques Clémenty, Michel Haïssaguerre 17 Emerging Technologies 260 Suneet Mittal, Jonathan Steinberg, Andrew Choi, Aysha Arshad GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page ix Aptara Inc Contents ix 18 Identification and Elimination of Ancillary Arrhythmias 273 Paolo Ferrero, Pietro Francia, Riccardo Cappato 19 Ablation Procedure Follow-up and Definitions of Success 281 Christopher Piorkowski, Gerd Hindricks, Hans Kottkamp 20 When and How to Re-Ablate 292 Michael Riley, David Callans 21 Postprocedural Care after Radiofrequency Catheter Ablation for Atrial Fibrillation 310 Alan Wimmer, Hakan Oral 22 Complications 320 Conor Barrett, Robert Schweikert, Walid Saliba, Jennifer Cummings, J David Burkhardt, Oussama Wazni, Andrea Natale 23 The Challenges of Monitoring Outcomes 346 Isabel Deisenhofer Index 357 GRBQ381-3653G-FM[i-xxiv].qxd 2/29/08 11:42 PM Page x Aptara Inc GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 120 Aptara, Inc 120 Part III ■ Mapping, Imaging, and Guidance Systems is used to introduce the MEA catheter Considering the aggressive anticoagulation therapy used during noncontact mapping, especially in LA-sided procedures, a gentle venous puncture to introduce the vascular sheath can help avoid any vascular complications Before the deployment of the MEA catheter in the atrium, physicians need to maintain an activated clotting time around 250 sec for right atrial (RA) and 350 sec for left atrial (LA) mapping in order to prevent thrombus formation The MEA catheter is deployed over a 0.035-inch guidewire, which has been advanced to the superior vena cava (SVC) for RA mapping (via the left femoral vein) and to the left superior PV for LA mapping (via the right femoral vein) (Fig 8.1) When we perform LA mapping, a double transseptal puncture is made using the standard Brockenbrough procedure before the deployment of the MEA catheter Next, we insert an exchangeable guidewire (0.035 inch, 260 cm, extra stiff) deep into the left superior PV through one of the transseptal sheaths, then remove the transseptal sheath, and insert the MEA into the LA over the guidewire The operator should Figure 8.1 Radiographs showing a multielectrode array catheter in the right atrium (MEA-RA), and left atrium (MEA-LA), exchangeable guidewire (GW ) inside the LA, duo-decapolar catheter in the coronary sinus, and ablation catheter around the high RA When we perform biatrial noncontact mapping, we usually place the MEA catheter into the LA over an exchangeable guidewire after establishing the RA geometry in order to limit the LA procedure time GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 121 Aptara, Inc Chapter 8 ■ Noncontact Mapping 121 confirm that both the E1 and E2 ring electrodes mounted on the MEA catheter are located inside the LA cavity We usually decrease the balloon profile by adjusting the volume of the injection mixture (contrast medium:heparinized saline, 30:70) that fills the balloon for LA and SVC mapping because it provides for an easier catheter manipulation around the space between the balloon and endocardial surface We initially position the MEA in the center of the atrial chamber, but if the origin of the ectopy initiating the AF is remote from the center of the MEA, we relocate the MEA to the proper position near the site of interest However, care must be taken to avoid occluding the ostium of the thoracic vein with the MEA balloon by delicately adjusting its position and the balloon profile How to Create an Endocardial Geometry Before the creation of the reconstructed geometry, it is recommended that a pre-evaluation of the anatomy of the atrial and thoracic vein be performed by selective venography and/or 3-D CT imaging in order to well understand the morphology of the atrium and thoracic vein complex (20–23,26,28,29) Digital image fusion using MR or CT imaging with endocardial geometry would also help in making a precise geometry (34) After the MEA is deployed in the chamber of interest, the operator manipulates the mapping catheter in order to tag the known anatomical structures demonstrated by the angiography, CT, or MR imaging for a quick procedure Then, a detailed endocardial geometry is constructed by sweeping the mapping catheter around in order to establish the entire geometry (Fig 8.2) When we perform biatrial noncontact mapping, we usually place the MEA catheter into the LA after first establishing the RA geometry in order to limit the total LA procedure time In particular, we carefully move the catheter around the areas between the SVC and RA appendage, left PVs and LA appendage, and inter-PV regions in order to create a precise anatomy The important anatomical locations such as the His bundle area, coronary sinus ostium, SVC, and four PVs, and also the RF lesion can be labeled on the geometry surface Interpretation of Noncontact Mapping After the creation of the endocardial geometry, the system software inside the workstation identifies 64 equally distributed locations and can display isopotential voltage maps from selected beats onto the reconstructed geometry surface Therefore, the operator can quickly check the activation wavefront with 3-D anatomical information as a computer-generated high-resolution “movie” in the review screen The operator can interactively place virtual signals at any site of interest on the color contours of the map in order to analyze the corresponding noncontact unipolar electrograms (20–23,26,28,29) Activation Mapping This system has two types of activation maps One is an isopotential map and the other is an isochronal map In the review mode, the physician can check the isopotential map propagation during tachycardias and also the unipolar electrogram morphology at any site of interest The color scale for each isopotential map has been set so that white indicates the most negative potentials and purple indicates the least negative potentials The color settings are adjusted so that the color range matches one to one with the millivolt range of the electrogram deflection of interest This system also can project single-beat isochronal maps of the activation time onto a virtual endocardial surface in the review mode The color scale for each isochronal map has been set so GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 122 Aptara, Inc Figure 8.2 An example showing the process of creating the right atrial geometry Before (upper panel) and after (middle panel) creation of the endocardial geometry displayed with a wire-frame model without the endocardial surface, and with the isopotential map superimposed on the reconstructed endocardial surface (lower panel) An ablation catheter is navigated to a site just next to the earliest activation site during ectopy originating from the crista terminalis See color insert 1 GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 123 Aptara, Inc Chapter 8 ■ Noncontact Mapping 123 that white indicates the earliest activation time and purple indicates the latest activation time According to the fundamentals of electrophysiology, the operator can observe two types of electrophysiological phenomena One is focal activation and the other is wavefront conduction The origin of the focal source is defined as the earliest site showing a single spot on the isopotential map and a QS pattern in the noncontact unipolar electrograms at that site However, physicians need to be sure that the noncontact electrograms at the origin of the focal source always exhibit multicomponents of the activation, because the wavefront from the focal area propagates through the preferential conduction area, reaches the breakout site, and spreads out to the rest of the atrium The propagation wavefront from the breakout site activates the area around the origin of the focal source Therefore, the initial component of the unipolar electrogram exhibiting a QS morphology represents focal activation, and the latter component of the unipolar electrogram exhibiting an rS morphology represents the “wrap around phenomenon” (Fig 8.3) Thus, physicians need to evaluate not only the pattern of the propagation in the isopotential map (a simple forward or U-turn conduction, stasis or slow conduction, reentry, collision or splitting) but also the morphology of the unipolar electrograms along the activation pathway (a QS or rS pattern, fractionation, or double potentials) This procedure is an important step when predicting the substrate of AF Figure 8.3 The effect of the high-pass filter setting on unipolar electrogram morphology The left panel shows the unipolar electrograms recorded from the origin of a focal source to its breakout site The noncontact electrogram at the origin of the focal source (Virtual 6) displays a multicomponent activation The wavefront from the focal area propagates through the preferential conduction region, then reaches the breakout site (Virtual 8), and spreads out to the entire atrium The propagation wavefront from the breakout site activates the area around the origin of the focal source The initial component of the unipolar electrogram with a QS morphology represents the focal activation and the latter component of the unipolar electrogram with an rS morphology represents the “wrap around phenomenon.” We usually begin the analysis with a default high-pass filter setting of 2 Hz to preserve the components of the low-amplitude depolarization or slow conduction The operator should be reminded that some components of the lowamplitude depolarization or slow conduction would be invisible when higher high-pass filter settings of the unipolar or bipolar electrograms are selected (middle and right panels) GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 124 Aptara, Inc 124 Part III ■ Mapping, Imaging, and Guidance Systems Figure 8.4 Definition of normalized negative unipolar voltage, and the ratio of the local peak negative voltage (PNV) of the unipolar electrogram to the maximal PNV of a selected beat of the entire right atrium (Reproduced from Huang JL, Tai CT, Lin YJ, et al Substrate mapping to detect abnormal atrial endocardium with slow conduction in patients with atypical right atrial flutter J Am Coll Cardiol 2006; 48:492–498.) Dynamic Substrate Mapping This system can perform not only activation mapping but also global voltage mapping for single-beat analysis (35,36) High-resolution voltage mapping—so-called “dynamic substrate mapping” (DSM)—can be obtained from the entire atrial chamber The DSM can be analyzed from the peak negative voltage (PNV) of the unipolar electrograms obtained from the entire atrial chamber, expressed as the normalized PNV value (the relative ratio to the maximal PNV) (Fig 8.4) We reported that the combination of the activation map and DMS function successfully detected the critical isthmus as an abnormal endocardium with slow conduction in the reentry circuit of the atypical atrial flutter, and a protected isthmus was bordered by low-voltage zones clearly presented as a convergence of the voltage lines (36) Thus, activation maps with DSM using noncontact mapping can provide important information on the substrate modification of macroreentry-maintaining AF Filter Settings for Noncontact Mapping The aim of adjusting the filter settings is to minimize noise and any atrial/ventricular repolarization waves to analyze true atrial depolarization Low-pass filters (25–300 Hz) are used to manage high-frequency components, such as environmental artificial noise High-pass filters (0.1–32 Hz) are used to manage low-frequency components, such as repolarization waves, and far-field signals from the epicardial side or neighboring chamber Thus, adjusting the high-pass filters during the review mode is the most frequent procedure performed by the operator to evaluate the activation wavefront We usually begin the analysis with a default high-pass filter setting of 2 Hz to preserve the components of the low-amplitude depolarization or slow conduction in the isopotential maps (Fig 8.3) (20–23,26,28,29) If conduction of the activation wavefront is assumed to be very slow, we adjust the high-pass filter setting down to 1.0 to 0.5 Hz In this way, the activation wavefront corresponding to the low-frequency signals will become visible on the isopotential map The operator should be reminded that some of the components of the low-amplitude depolarizations or slow conduction will become invisible when higher high-pass filter settings are selected When evaluating the origin of a focal activation with a low-amplitude depolarization signal or diastolic depolarization during macroreentry, it is a very important step to adjust the high-pass filter down to 1.0 to 0.5 Hz (Table 8.1) Application of Noncontact Mapping for Atrial Fibrillation Ablation Currently, several strategies are being used to treat AF, including thoracic vein isolation, circumferential ablation around the PV antrum, focal ablation to eliminate GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 125 Aptara, Inc Chapter 8 ■ Noncontact Mapping TABLE 8.1 125 Troubleshooting Noncontact Mapping–Guided Ablation of Atrial Fibrillation Problem Causes Solutions Unable to localize the ectopy initiating the AF or macroreentry maintaining the AF • Misinterpretation of the ectopic beat electrogram • Exclude the far-field potentials by simultaneous mapping of the SVC, CT, and RSPV • Exclude the far-field potentials by simultaneous mapping of the LSPV, LIPV, LA, and LOM, and apply the differential pacing method to identify the PV or atrial potentials • Low-amplitude signals filtered out • Change the high-pass filter setting to a lower number to view the low-amplitude depolarizations or very slow conduction • Atrial depolarization masked by T-wave • Choose segments without the ventricular repolarization and re-analyze the data • Change the high-pass filter setting to a higher number to reduce the ventricular repolarization interference • Insert ventricular stimuli or load with adenosine to see the true atrial depolarization • Outside the mapping area • Relocate the MEA catheter closer to the area of interest • Use the NavX system or CARTO when the patient has a large atrium • Interatrial shifting of the ectopy or macroreentry • Consider biatrial noncontact mapping AF, atrial fibrillation; CT, crista terminalis; LA, left atrium; LIPV, left inferior pulmonary vein; LOM, ligament of Marshall; LSPV, left superior pulmonary vein; MEA, multielectrode array; RA, right atrium; RSPV, right superior pulmonary vein; SVC, superior vena cava extra-PV ectopies, fractionated electrograms and high-frequency sources of AF drivers using frequency domain analysis, and linear ablation to prevent macroreentrymaintaining AF (3,4,5,23,37–40) Noncontact mapping can be applied for guidance in all of these strategies Ectopy-Initiating Atrial Fibrillation Pulmonary Veins For AF initiators originating from the PVs, we encircle the PV antrum until PV isolation is achieved under the guidance of noncontact mapping However, noncontact mapping has no specific advantages for PV isolation itself as compared with the circular catheter mapping technique GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 126 Aptara, Inc 126 Part III ■ Mapping, Imaging, and Guidance Systems Left Atrium Free Wall For AF initiators originating from the LA free wall, we target the earliest activation site during the ectopy and perform a focal ablation until total elimination of the ectopy under the guidance of noncontact mapping is achieved (Fig 8.5) If the ectopy still remains, a box-shaped linear ablation surrounding the earliest site is added (16,20–22) Superior Vena Cava For AF initiators originating from the SVC, we perform an SVC isolation at a level of about 5 mm below the RA–SVC junction (16,20–22) Noncontact mapping can demonstrate the location of the electrical breakthrough sites and sinus node origin, and guide the SVC isolation procedure without any injury to the sinus node (Fig 8.6) A B Figure 8.5 A: Isochronal maps during ectopy from the LA posterior wall initiating AF The color scale for each isochronal map has been set so that white indicates the earliest activation time and purple the latest activation time The focal activation originates from the LA middle posterior wall, then unidirectional block occurs on the left side of the posterior wall, and the activation wavefront spreads around the RPVs to the rest of the LA (yellow arrows), and then initiates AF B: Unipolar virtual signals from the ectopic focus (Virtual 6, from the second beat) demonstrating a QS morphology, and the breakout site (Virtual 8, from the second beat) exhibiting an rS morphology LAA, left atrial appendage; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; RSPV, right superior pulmonary vein See color insert 1 GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 127 Aptara, Inc Chapter 8 ■ Noncontact Mapping 127 Figure 8.6 Noncontact mapping–guided superior vena cava isolation A: An isochronal map during the SVC ectopy The ectopic beat originates from the SVC and conducts via an electrical breakthrough to the RA Virtuals 7 and 8 exhibit a QS pattern (ectopic focus), and Virtuals 9 through 11 exhibit an rS pattern B: The origin of the sinus node is located at the anterior portion of the RA–SVC junction near the electrical breakthrough site (Frame 1) The activation wavefront propagates to the high anterior RA (Frame 2), and spreads away to the rest of the RA (Frame 3) C: Noncontact mapping–guided SVC isolation The frames (1–6) show the endocardial geometry of the RA–SVC complex RF lesions are indicated as brown circles In Frames 1 and 2, the electrical breakthrough site is located at the posterolateral portion of the RA–SVC junction and the origin of the sinus node impulse is located on the anterolateral RA wall below the RA–SVC junction In Frames 3 and 4, the electrical breakthrough site is located at the anterolateral portion of the RA–SVC junction and the origin of the sinus node impulse is located just below the electrical breakthrough site In this case, we carefully carried out the applications of the RF energy to the anterolateral portion of the RA–SVC junction near the origin of the sinus node impulse and successfully isolated the superior vena cava without any sinus node injury In Frames 5 and 6, the electrical breakthrough sites are distributed along the full circumference of the entire RA–SVC junction, and the origin of the sinus node impulse is located at the anterior portion of the RA–SVC junction In this case, the physician had to carefully apply the RF application to the anterior portion of the RA–SVC junction near the origin of the sinus node impulse in order to avoid the possibility of any sinus node injury SN, sinus node; SVC superior vena cava (Reproduced from Higa S, Tai CT, Chen SA Catheter ablation of atrial fibrillation originating from extrapulmonary vein areas: Taipei approach Heart Rhythm 2006;3:1386–1390.) See color insert 1 Crista Terminalis For AF initiators originating from the crista terminalis, we target the earliest activation site during the ectopy and perform a focal ablation until total elimination of the ectopy under the guidance of noncontact mapping is achieved (9,16,20–23) (Figs 8.7, 8.8) Reentrant Type AF (Without Ectopy-Initiating AF) This laboratory reported that around 3% of all paroxysmal AF had no inducible ectopy-initiating AF (23) A comparison of the AF cycle length or highest dominant frequency in the RA free wall and septal wall can help to predict the location of the reentrant circuit responsible for AF maintenance Noncontact mapping can demonstrate that AF can be driven by a single- or double-loop reentry, and wavefront splitting around the AF driver results in fibrillatory conduction in this population of AF In these cases, we usually perform a linear ablation to block the critical channels between the lines of conduction block responsible for the AF (Fig 8.9) GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 128 Aptara, Inc 128 Part III ■ Mapping, Imaging, and Guidance Systems A B Figure 8.7 Noncontact mapping demonstrates the spontaneous initiation of a crista terminalis–origin AF A, B: Isochronal maps and unipolar virtual electrograms of the first two beats initiating the AF in the posterior oblique view For the color scale of each isochronal map, white indicates the earliest activation site and purple the latest activation site The wavefront propagates from the earliest site in the middle portion of the crista terminalis (yellow long arrow) (A) Unidirectional block then occurs in the lower portion of the crista terminalis (yellow short arrow) and the activation wavefront spreads around the upper portion of the crista terminalis initiating reentry in the second cycle of AF (yellow long arrow) (B) The unipolar virtual signals from the ectopic focus (virtual 6, from the first cycle) have a “QS” morphology and those from the second cycle have an “rS” morphology CSO, coronary sinus ostium; IVC, inferior vena cava; RAA, right atrial appendage; SVC, superior vena cava (Reproduced from Lin YJ, Tai CT, Liu TY, et al Electrophysiological mechanisms and catheter ablation of complex atrial arrhythmias from crista terminalis: insight from three-dimensional noncontact mapping Pacing Clin Electrophysiol 2004;27:1232–1239.) See color insert 1 Noncontact Mapping for Catheter Ablation of Persistent Atrial Fibrillation The modification of the atrial substrate is an important procedure for curing persistent AF (40) Noncontact mapping can guide the isolation of all four PVs and linear ablation of the cavotricuspid isthmus, mitral isthmus, and LA roof line in patients with persistent AF If AF continues after making those lesions, this system also can map any induced focal ATs or macroreentrant circuits after restoring sinus rhythm by cardioversion If the ectopy initiating the AF and/or macroreentry maintaining the AF exhibits interatrial shifting, biatrial noncontact mapping may help to guide the AF ablation (Fig.8.10) (41,42) Limitations and Contraindications of Noncontact Mapping Although noncontact mapping has the clear advantage of identifying extra-PV ectopy-initiating AF and unstable macroreentrant circuits maintaining AF over the other mapping systems, this system has several limitations Attention needs to be paid to the distance between the mapping site and the center of the balloon (43) Accuracy may decrease in an area with a distance from balloon center of more than 40 mm GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 129 Aptara, Inc Chapter 8 ■ Noncontact Mapping A E I B C D F G H 129 J Figure 8.8 Isopotential maps (A–H), virtual electrograms (I), and surface electrograms (J) during AF that exhibit a short-radius fast reentry circuit with fibrillatory conduction emerging after the first atrial reentry circuit as shown in Figure 8.10 during AF initiation The color scale for each isopotential map displays the most negative potential in white and least negative potential in purple The timing in each panel is indicated by the “A to H” written above the time scale in Panel I During spontaneous AF initiation, the wavefront propagates around the upper CT and splits into two wavefronts near the lower anterior wall (A, B) Then, one wavefront travels through the gap in the lower portion of the CT, the other wavefront passes through the cavotricuspid isthmus, and the latter wavefront fuses with the prior wavefront in the posterior septal wall (C, D) The activation wavefront also propagates from the high RA down to the anterolateral wall once again, and exhibits wavefront splitting (E, F) The wavefront splitting just after the activation wavefront passes through the crista terminalis gap results in fibrillatory conduction (G, H) (Reproduced from Lin YJ, Tai CT, Liu TY, et al Electrophysiological mechanisms and catheter ablation of complex atrial arrhythmias from crista terminalis: insight from three-dimensional noncontact mapping Pacing Clin Electrophysiol 2004;27:1232–1239.) See color insert 1 If the patient has a large cardiac chamber, the virtual electrograms may have a limited reliability Therefore, contact mapping with a 3-D navigation system such as CARTO or the EnSite NavX system should be recommended in such cases (Table 8.1) Patients with a hypercoagulated condition, intolerance to anticoagulation with heparin, an artificial valve in the chamber of interest, or a recent history of cardiac atriotomy are contraindicated for noncontact mapping Conclusion Noncontact mapping has the specific advantage of being able to map extra-PV ectopies and macroreentrant circuits that can initiate and maintain AF because of its high-resolution mapping for a single-beat analysis Considering the relatively high incidence of extra-PV AF, this system will be a useful tool for the guidance of curative GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 130 Aptara, Inc A B C Figure 8.9 Isochronal maps, frequency domain analysis, and the intracardiac unipolar electrograms revealing the reentrant circuit in the RA during a spontaneous transition from an atypical atrial flutter to AF A: The isochronal map shows that the activation wavefront propagates through the channels between the lines of conduction block (black lines) during low anterolateral wall pacing before the induction of AF B: Spontaneous transition from an atypical atrial flutter to AF The timing for each frame (B1 to B8) is indicated by the “1–8” on surface ECG lead aVF The isopotential maps demonstrate that the activation wavefront of the macroreentry propagates through the same channels as in Panel A between the lines of block in the CT and free wall to complete the reentrant circuit of the atypical AFL (Frames 1–3) During the conversion to AF, the reentry circuit repetitively propagates via the channel between the CT and free wall (near Site 1), and splits into two wavefronts (Frame 4) Each of the wavefronts further split into two wavelets traveling superiorly and inferiorly, thereby generating fibrillatory conduction due to the existence of four simultaneous wavefronts (Frames 5–6) The more superior wavefront (AF driver) fuses in the superior RA, while the more inferior wavefronts (daughter wavelets, indicated by the green arrows) fuse and travel through the cavotricuspid isthmus and fuse with the prior superior wavefront (Frames 6–7) The subsequent activation maps show a continuing complex pattern around the two conduction block lines in the CT and free wall (Frames 7–8) C: The local unipolar virtual electrograms demonstrate a relatively regular activation along the circuit (Sites 1 and 2), and irregular activation outside the circuit (Sites 3 and 4) Site 5 is near the margin of the reentrant circuit with a power amplitude of 0.27, which meets the criteria of a DF The regional spectral analysis demonstrates that the maximal DF with the largest power amplitude is located along the circuit Linear ablation (white dashed line in Panel A) connecting the lines of block successfully eliminated the AF without any further induction of AF (Reproduced from Lin YJ, Tai CT, Kao T, et al Electrophysiological characteristics and catheter ablation in patients with paroxysmal right atrial fibrillation Circulation 2005;112:1692–1700.) See color insert 1 GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 131 Aptara, Inc Chapter 8 ■ Noncontact Mapping A 131 B Figure 8.10 Noncontact mapping demonstrates macroreentry in the LA and RA after a PV antrum circumferential ablation with isolation of all four PVs in a patient with persistent AF This case shows an interatrial shifting of the macroreentrant circuit between the LA and RA Simultaneous biatrial noncontact mapping successfully detected the critical isthmus of each macroreentrant circuit The noncontact mapping guided the linear ablation to the mitral isthmus and a roof line in the LA, and of the gap conduction in the CT for the RA, successfully eliminating the AF Panels A and B demonstrate the isochronal maps and unipolar virtual electrograms in the posterior oblique view For the color scale of each isochronal map, white indicates the earliest activation site and purple the latest activation site A: Peri-LPV reentry The wavefront propagates from the anterior roof near the LSPV, travels down the posterior wall, and slowly propagates along the mitral isthmus to complete the reentry circuit (yellow long arrow) The lower panel shows the unipolar electrograms along the mitral isthmus that demonstrate fragmented electrograms (Virtuals 8, 9), with slow conduction On the other hand, the unipolar electrograms outside the isthmus demonstrate an rS pattern (Virtuals 5–7) B: Upper loop reentry The wavefront propagates from the anterior portion of the RAA, then travels down the RA free wall, and slowly propagates through the gap conduction region in the CT to complete the reentry circuit (yellow long arrow) The lower panel shows the unipolar electrograms along the gap conduction region in the CT that exhibit fragmented electrograms (Virtuals 7, 8), with slow conduction On the other hand, the unipolar electrograms outside the isthmus demonstrate an rS pattern (Virtuals 5, 6, 9) CT, crista terminalis; IVC, inferior vena cava; LAA, left atrial appendage; LIPV, left inferior pulmonary vein; LSPV, left superior pulmonary vein; RAA, right atrial appendage; RIPV, right inferior pulmonary vein; RSPV, right superior pulmonary vein; SVC, superior vena cava See color insert 2 ablation of AF Physicians can consider the use of this system in initial and re-do procedures Acknowledgements We appreciate the secretarial work provided by Miss Chi and Miss Chen from Taipei Veterans General Hospital References 1 Haissaguerre M, Jais P, Shah DC, et al Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins N Engl J Med 1998;339:659–666 2 Chen SA, Hsieh MH, Tai CT, et al Initiation of atrial fibrillation by ectopic beats originating from the pulmonary veins: electrophysiological characteristics, pharmacological responses, and effects of radiofrequency ablation Circulation 1999;100:1879–1886 GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 132 Aptara, Inc 132 Part III ■ Mapping, Imaging, and Guidance Systems 3 Pappone C, Oreto G, Rosanio S, et al Atrial electroanatomic remodeling after circumferential radiofrequency pulmonary vein ablation: efficacy of an anatomic approach in a large cohort of patients with atrial fibrillation Circulation 2001;104:2539–2544 4 Oral H, Knight BP, Tada H, et al Pulmonary vein isolation for paroxysmal and persistent atrial fibrillation Circulation 2002;105:1077–1081 5 Chen SA, Tai CT, Yu WC, et al Right atrial focal atrial fibrillation: electrophysiologic characteristics and radiofrequency catheter ablation J Cardiovasc Electrophysiol 1999;10:328–335 6 Tsai CF, Tai CT, Hsieh MH, et al Initiation of atrial fibrillation by ectopic beats originating from the superior vena cava Electrophysiological characteristics and results of radiofrequency ablation Circulation 2000;102:67–74 7 Hwang C, Chen PS Clinical electrophysiology and catheter ablation of atrial fibrillation from the ligament of Marshall In: Chen SA, Haissaguerre M, Zipes DP eds Thoracic Vein Arrhythmias: Mechanisms and Treatment 1st ed Malden, MA: Blackwell Futura Publishing Co.; 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Pacing Clin Electrophysiol 2003;26:1631–1635 18 Beldner SJ, Zado ES, Lin D, et al Anatomic targets for non-pulmonary triggers: identification with intracardiac echo and magnetic mapping Heart Rhythm 2004;1:S237 19 Suzuki K, Nagata Y, Goya M, et al Impact of non-pulmonary vein focus on early recurrence of atrial fibrillation after pulmonary vein isolation Heart Rhythm 2004;1(Suppl):S203–204 20 Chen SA, Tai CT Catheter ablation of atrial fibrillation originating from the non-pulmonary vein foci J Cardiovasc Electrophysiol 2005;16:229–232 21 Higa S, Tai CT, Chen SA Catheter ablation of paroxysmal atrial fibrillation originating from the non-pulmonary vein areas In: Huang S and Wood M, eds Catheter Ablation of Cardiac Arrhythmias 1st ed Burlington, MA: Elsevier Science; 2006: 289–304 22 Higa S, Tai CT, Chen SA Catheter ablation of atrial fibrillation originating from extrapulmonary vein areas: Taipei approach Heart Rhythm 2006;3:1386–1390 23 Lin YJ, Tai CT, Kao T, et al Electrophysiological characteristics and catheter ablation in patients with paroxysmal right atrial fibrillation Circulation 2005;112:1692–700 24 Ouyang F, Antz M, Ernst S, et al Recovered pulmonary vein conduction as a dominant factor for recurrent atrial tachyarrhythmias after complete circular isolation of the pulmonary veins: lessons from double Lasso technique Circulation 2005;111:127–135 GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 133 Aptara, Inc Chapter 8 ■ Noncontact Mapping 133 25 Schmitt C, Ndrepepa G, Weber S, et al Biatrial multisite mapping of atrial premature complexes triggering onset of atrial fibrillation Am J Cardiol 2002;89:1381–1387 26 Liu TY, Tai CT, Lee PC, et al Novel concept of atrial tachyarrhythmias originating from the superior vena cava: insight from noncontact mapping J Cardiovasc Electrophysiol 2003;14:533–539 27 Weiss C, Willems S, Rostock T, et al Electrical disconnection of an arrhythmogenic superior vena cava with discrete radiofrequency current lesions guided by noncontact mapping Pacing Clin Electrophysiol 2003;26:1758–1761 28 Lin YJ, Tai CT, Liu TY, et al Electrophysiological mechanisms and catheter ablation of complex atrial arrhythmias from crista terminalis: insight from three-dimensional noncontact mapping Pacing Clin Electrophysiol 2004;27:1232–1239 29 Liu TY, Tai CT, Lee PC, et al Novel concept of atrial tachyarrhythmias originating from the superior vena cava: insight from noncontact mapping J Cardiovasc Electrophysiol 2003;14:533–539 30 Gasparini M, Coltorti F, Mantica M, et al Noncontact system–guided simplified right atrial linear lesions using radiofrequency transcatheter ablation for treatment of refractory atrial fibrillation Pacing Clin Electrophysiol 2000;23(11 Pt 2):1843–1847 31 Schneider MA, Ndrepepa G, Zrenner B, et al Noncontact mapping–guided catheter ablation of atrial fibrillation associated with left atrial ectopy J Cardiovasc Electrophysiol 2000;11:475–479 32 Saksena S, Skadsberg ND, Rao HB, et al Biatrial and three-dimensional mapping of spontaneous atrial arrhythmias in patients with refractory atrial fibrillation J Cardiovasc Electrophysiol 2005;16:494–504 33 Pak HN, Hwang C, Lim HE, et al Electroanatomic characteristics of atrial premature beats triggering atrial fibrillation in patients with persistent versus paroxysmal atrial fibrillation J Cardiovasc Electrophysiol 2006;17:818–824 34 Sra J, Krum D, Hare J, et al Feasibility and validation of registration of three-dimensional left atrial models derived from computed tomography with a noncontact cardiac mapping system Heart Rhythm 2005;2:55–63 35 Liu TY, Tai CT, Huang BH, et al Functional characterization of the crista terminalis in patients with atrial flutter: implications for radiofrequency ablation J Am Coll Cardiol 2004; 43:1639–1645 36 Huang JL, Tai CT, Lin YJ, et al Substrate mapping to detect abnormal atrial endocardium with slow conduction in patients with atypical right atrial flutter J Am Coll Cardiol 2006; 48:492–498 37 Nademanee K, McKenzie J, Kosar E, et al A new approach for catheter ablation of atrial fibrillation: mapping of the electrophysiologic substrate J Am Coll Cardiol 2004;43: 2044–2453 38 Haissaguerre M, Hocini M, Sanders P, et al Localized sources maintaining atrial fibrillation organized by prior ablation Circulation 2006;113:616–625 39 Sanders P, Berenfeld O, Hocini M, et al Spectral analysis identifies sites of high-frequency activity maintaining atrial fibrillation in humans Circulation 2005;112:789–797 40 Haissaguerre M, Hocini M, Sanders P, et al Catheter ablation of long-lasting persistent atrial fibrillation: clinical outcome and mechanisms of subsequent arrhythmias J Cardiovasc Electrophysiol 2005;16:1138–1147 41 Lemery R, Soucie L, Martin B, et al Human study of biatrial electrical coupling: determinants of endocardial septal activation and conduction over interatrial connections Circulation 2004;110:2083–2089 42 Schmitt C, Ndrepepa G, Weber S, et al Biatrial multisite mapping of atrial premature complexes triggering onset of atrial fibrillation Am J Cardiol 2002;89:1381–1387 43 Earley MJ, Abrams DJ, Sporton SC, et al Validation of the noncontact mapping system in the left atrium during permanent atrial fibrillation and sinus rhythm J Am Coll Cardiol 2006;48:485–491 GRBQ381-3653G-C08[118-134].qxd 2/29/08 8:26AM Page 134 Aptara, Inc ... 2006;48(7) :15 03? ?15 17 Cappato R, Calkins H, Chen SA, et al Worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation Circulation 2005 ;11 1(9) :11 00? ?11 05 GRBQ3 81- 3653G-C02 [11 -24].qxd... — 4Ϯ5 5Ϯ3 8Ϯ4 14 Ϯ5 12 21? ?5 11 Ϯ8 Follow up (mo) 526/740( 71) 51/ 70(73) 44/70(63) 38/75( 51) 2 71/ 315 (86) 34/55(62) 27/40(67) 22/40(55) 39/75(52) Overall 19 6/280(70) 51/ 707(3) 41/ 58( 71) N/A N/A 26/37(70)... considered for catheter ablation of AF Also reviewed GRBQ3 81- 3653G-C 01[ 01- 10].qxd 2/29/08 8:21AM Page Aptara, Inc Part I ■ Introduction and Historical Perspective TABLE 1. 1 Areas of Consensus: