Image integration using intracardiac ultrasound and 3D reconstruction for scar mapping and ablation of ventricular tachycardia.
BACKGROUND
Ablation of ventricular tachycardia (VT) reduces implantable cardioverter defibrillator shocks. Intracardiac ultrasound (ICE) can visualize and quantify the function of all left ventricular wall segments. We thus hypothesized that ICE could identify scar tissue and provide a guide to facilitate substrate-guided VT ablation.


METHODS
Eighteen patients underwent VT ablation with real time ICE mapping from the right atrium and ventricle with online 3D-image reconstruction of scar segments. The left ventricle was also scar mapped by traditional electroanatomic mapping (CARTO) for comparison. Images from these 2 scar mapping techniques were compared to each other as well as to a preprocedure transthoracic echocardiogram.


RESULTS
The average age was 65 +/- 12 years and 12 (67%) were male (15 [83%] had ischemic cardiomyopathy). Two patients (12%) had recurrence of their clinical VT (1 remained on an antiarrhythmic medication, the other had a repeat ablation) over a follow-up of 127 +/- 33 days. No periprocedural or long-term adverse events occurred. A total of 248 wall segments were analyzed. All 3 modalities were concordant in scar identification in 193 (78%) segments. The ICE segments correlated with the electroanatomic map in 213 (86%) segments versus 198 (80%), which correlated with transthoracic echocardiography and electroanatomic mapping (P = 0.046). Specifically, the ICE wall motion scores were closer to the electroanatomic mapping in the basal segments and showed a higher accuracy in ischemic heart disease.


CONCLUSIONS
These data demonstrate that real time ICE images provide accurate chamber geometries and scar boundaries of the left ventricle. These scar borders were more accurate than transthoracic echocardiography and illustrate the feasibility of ICE for substrate-based ablation for VT.
Bunch
T Jared
TJ
Intermountain Heart Rhythm Specialists, Department of Cardiology, Intermountain Medical Center, Murray, Utah 84107, USA. Thomas.bunch@imail.org
Weiss
J Peter
JP
Crandall
Brian G
BG
Day
John D
JD
DiMarco
John P
JP
Ferguson
John D
JD
Mason
Pamela K
PK
McDaniel
George
G
Osborn
Jeffrey S
JS
Wiggins
Dave
D
Mahapatra
Srijoy
S
D000368:Aged; D017115:Catheter Ablation / Q000379:methods*; D004452:Echocardiography; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D025321:Surgery, Computer-Assisted; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging* / Q000601:surgery*