Initial experience with a steerable intracardiac echocardiographic catheter.
BACKGROUND
Intracardiac echocardiography (ICE) has been used to guide radiofrequency catheter ablation procedures and transseptal punctures. The ability to position current ICE catheters is limited. In this study, we report on the initial experience with a steerable ICE catheter in a canine model and in man.


METHODS
In a canine model, we compared the image quality and maneuverability of a 9 French (Fr), 9 MHz ICE catheter and a custom 9 Fr, 9 MHz steerable ICE catheter. Imaging was attempted at 7 intracardiac sites. Non-steerable catheter positioning was attempted with the catheter alone or with the curved, long 10 Fr vascular sheath. Steerable catheter positioning was attempted with the catheter alone after the vascular sheath was withdrawn into the inferior vena cava. The steerable ICE catheter was also used to help guide catheter ablation in a patient with right ventricular outflow tract (RVOT) tachycardia.


RESULTS
The steerable ICE catheter was easily positioned at all 7 predetermined sites without the need for a long vascular sheath. In contrast, the non-steerable catheter was much more difficult to position. Image quality was similar for both catheters; depths of imaging were 4-8 cm, depending on catheter location. Multiple image planes could be achieved at a single site with tip deflection of the steerable catheter. In man, the steerable catheter was easily positioned to the RVOT. ICE imaging was helpful in positioning the ablation catheter below the pulmonic valve and ensuring good electrode-tissue contact during energy delivery.


CONCLUSIONS
Steerability improved maneuverability and added multiple image planes compared to a non-steerable ICE catheter. Steerability may enhance the utility of ICE in guiding catheter ablation procedures.
Epstein
L M
LM
Cardiovascular Division, Beth Israel Deaconess Medical Center, East Campus, 330 Brookline Avenue, Boston, MA 02215, USA. lepstein@bidmc.harvard.edu
Smith
T W
TW
D000328:Adult; D000818:Animals; D017115:Catheter Ablation; D002404:Catheterization / Q000592:standards; D004285:Dogs; D004452:Echocardiography / Q000295:instrumentation*; D004867:Equipment Design; D005260:Female; D006801:Humans; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging* / Q000601:surgery*