Phased-Array Intracardiac Echocardiography During Pulmonary Vein Isolation and Linear Ablation for Atrial Fibrillation ROBERT E. MARTIN, M.D., KENNETH A. ELLENBOGEN, M.D., YUNG R. LAU, M.D.,* JEFF A. HALL, D.V.M.,† G. NEAL KAY, M.D.,‡ RICHARD K. SHEPARD, M.D, J.V. NIXON, M.D., and MARK A. WOOD, M.D. From the Department of Internal Medicine, Division of Cardiology, Virginia Commonwealth University’s Medical College of Virginia, Richmond, Virginia; *Division of Pediatric Cardiology, University of Alabama at Birmingham, Birmingham, Alabama; †Guidant Corporation, St. Paul, Minnesota; and the ‡Department of Internal Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama Phased-Array Intracardiac Echocardiography for AF Ablation. Introduction: Fluoroscopic imaging provides limited anatomic guidance for left atrial structures. The aim of this study was to determine the utility of real-time, phased-array intracardiac echocardiography during radiofrequency ablation for atrial brillation. Methods and Results: In 29 patients undergoing pulmonary vein isolation (n 5 16) or linear (n 5 13) left atrial radiofrequency ablation for atrial brillation, intracardiac phased-array echocardiography was used to visualize left atrial anatomy and the pulmonary veins, as well as ablation and mapping catheters during ablation procedures. In the 16 pulmonary vein isolation patients, the mean pulmonary vein ostial diameters measured by venography and intracardiac echocardiography were similar for all veins posi- tions, except that left common pulmonary vein diameters were larger as measured by echocardiography (2.50 6 0.29 cm) than by venography (1.79 6 0.50 cm, P 5 0.001). The ostial diameters measured by echocardiography and venography were not correlated, however (r 5 0.23, P 5 0.19). As directed by echocardiography, only 1 of 25 circular mapping catheters (4%) used in 16 patients was replaced due to inappropriate sizing of the pulmonary veins. Mean pulmonary vein Doppler ow velocities increased after ablation for left-sided veins but ostial diameters were unchanged. In the linear ablation patients, the entire extent of the linear electrode array could be visualized in only 3 of 52 of catheter positions (6%) in the 13 patients. A portion of the catheter could be seen in only 50% of all target catheter positions. Conclusion: Phased-array intracardiac echocardiography (1) allows sizing and positioning of pulmo- nary vein mapping catheters, (2) provides measures of pulmonary vein ostial diameters, (3) continuously monitors pulmonary vein Doppler ow velocities, and (4) has limited use in positioning linear ablation catheters in the left atrium. (J Cardiovasc Electrophysiol, Vol. 13, pp. 873-879, September 2002) atrial brillation, intracardiac echocardiography, radiofrequency ablation, pulmonary veins Introduction Atrial brillation is a signicant health problem in the United States, affecting 1% of the adult population. 1 Phar- macologic attempts at maintaining sinus rhythm are associ- ated with a low long-term success rate. 2 Nonpharmacologic methods of restoring sinus rhythm include the surgical maze procedure and catheter ablation. The surgical maze proce- dure has been successful at maintaining sinus rhythm; how- ever, this approach usually is reserved for patients who require median sternotomy for other indications. Catheter- based attempts at preventing atrial brillation are based on two approaches: (1) creating linear lesions in the atria to emulate the surgical maze procedure, and (2) ablating focal initiators of atrial brillation that most commonly arise from the pulmonary veins. 3-6 Regardless of the approach, precise catheter placement within the left atrium is necessary. Placement of catheters under uoroscopic guidance is se- verely limited by the inability to assess electrode-tissue contact and the inability to visualize structures such as the pulmonary veins without repeated contrast injection. Intra- cardiac echocardiography can visualize cardiac and pul- monary vein anatomy continuously without contrast or ra- diation exposure; however, the utility of intracardiac echo- cardiography in complex left atrial ablation procedures has not been fully determined. 7,8 The aim of this study was to prospectively describe the use of phased-array intracardiac echocardiography during linear ablation and pulmonary vein isolation procedures for atrial brillation. Methods Patient Study Group Twenty-nine consecutive patients referred for manage- ment of drug-refractory, highly symptomatic atrial brilla- tion were prospectively studied with phased-array intracar- diac echocardiography at The Medical College of Virginia and the University of Alabama at Birmingham. Patient characteristics are listed in Table 1. Patients with persistent or paroxysmal atrial brillation were included in this study. All patients gave informed written consent to the proce- Address for correspondence: Mark A. Wood, M.D., Medical College of Virginia, West Hospital, East Wing, Room 567, 1200 East Broad Street, Richmond, VA 23219. Fax: 804-828-6028; E-mail: mwoodmd@pol.net Manuscript received 10 June 2002; Accepted for publication 1 August 2002. 873 Reprinted with permission from JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Volume 13, No. 9, September 2002 Copyright ©2002 by Futura Publishing Company, Inc., Armonk, NY 10504-0418