Author + information
- Received June 9, 1993
- Revision received May 11, 1994
- Accepted June 2, 1994
- Published online November 1, 1994.
- Edward Chu, MD1,
- Jonathan M. Kalman, MBBS, FRACP2,
- Michael A. Kwasman, MD,
- John C.Y. Jue, MD,
- Peter J. Fitzgerald, MD3,
- Laurence M. Epstein, MD, FACC,
- Nelson B. Schiller, MD, FACC,
- Paul G. Yock, MD, FACC3 and
- Michael D. Lesh, MD, FACC∗
- ↵∗Address for correspondence: Dr. Michael D. Lesh, Department of Medicine and Cardiovascular Research Institute, Room MU 428, University of California, San Francisco, Box 1354, San Francisco, California 94143-1354.
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.
↵1 Dr. Chu is funded by the U.S. Army Medical Department, Washington, D.C.
↵2 Dr. Kalman is funded as the Ralph Reader Overseas Research Fellow of the National Heart Foundation of Australia and is the recipient of a Telectronics traveling grant from the Royal Australasian College of Physicians, Sydney, Australia.
↵3 Drs. Yock and Fitzgerald are consultants to, and have an equity interest in, CVIS, Cardiovascular Imaging Systems, Sunnyvale, California.
☆ This study was presented in part at the 14th Annual Scientific Session of the North American Society for Pacing and Electrophysiology, May 1993.
☆☆ All editorial decisions for this article, including selection of referees, were made by a Guest Editor. This policy applies to all articles with authors from the University of California, San Francisco.
- Received June 9, 1993.
- Revision received May 11, 1994.
- Accepted June 2, 1994.