Development of an electrophysiology (EP)-enabled intracardiac ultrasound catheter integrated with NavX 3-dimensional electrofield mapping for guiding cardiac EP interventions: experimental studies.
OBJECTIVE
We have developed an integrated high-resolution intracardiac echocardiography (ICE) catheter for electrophysiology (EP) testing, which can be coregistered in 3-dimensional space with EP testing and ablation catheters using electrofield sensing.


METHODS
Twelve open-chest pigs (34-55 kg) and 3 closed-chest pigs were studied. After introduction from the jugular or femoral venous locations, the 9F side-looking, highly steerable (0 degrees -180 degrees), 64-element array catheters could be manipulated easily throughout the right side of the heart. Multisite cardiac pacing was performed for assessing left ventricular (LV) synchrony using tissue Doppler methods. Also, in the open-chest pigs, right atrial (RA) and right ventricular (RV) ablations were performed with a separate radio frequency catheter under fluoroscopic guidance and visualized with ICE to characterize the changes. In the 3 closed-chest pigs, electrofield NavX 3-dimensional coregistration (St Jude Medical Corp, Minneapolis, MN) allowed us to test whether this additional feature could shorten the time necessary to perform 4 targeted ablations in each animal while imaging the ablation catheter and the adjacent region by ICE.


RESULTS
Intracardiac anatomy, tricuspid, aortic, pulmonary, and mitral valve function, and pulmonary vein flow were all imaged reproducibly from scanning locations in the RA or RV in all animals, along with assessment of cardiac motion and the effects of multisite pacing. Three-dimensional electrofield displays detailed the spatial relationship between the ICE catheter and ablation catheters such that the time to visualize and ablate 4 sites in each of the 3 closed-chest animals was reduced.


CONCLUSIONS
This new technology is a first step in the integration of ICE with EP procedures.
Li
Xiao Kui
XK
Oregon Health and Science University, 3181 SW Sam Jackson Park Rd, L608, Portland, OR 97239-3098, USA.
Pemberton
James
J
Thomenius
Kai
K
Dentinger
Aaron
A
Lowe
Robert I
RI
Ashraf
Muhammad
M
Shung
K Kirk
KK
Chia
Raymond
R
Stephens
Douglas N
DN
O'Donnell
Matthew
M
Mahajan
Aman
A
Balaji
Seshadri
S
Shivkumar
Kalyanam
K
Sahn
David J
DJ
D000818:Animals; D018780:Body Surface Potential Mapping / Q000295:instrumentation* / Q000379:methods; D006328:Cardiac Catheterization / Q000295:instrumentation* / Q000379:methods; D019560:Echocardiography, Three-Dimensional / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D013552:Swine; D014159:Transducers; D018084:Ultrasonography, Interventional / Q000295:instrumentation* / Q000379:methods