Right ventricular substrate mapping using the Ensite Navx system: Accuracy of high-density voltage map obtained by automatic point acquisition during geometry reconstruction.
BACKGROUND
Contact point-to-point electroanatomic mapping (Pt-Map) is a validated tool to evaluate right ventricular (RV) substrate. When using the EnSite NavX system (St. Jude Medical, St Paul, Minnesota), geometry reconstruction by dragging the mapping catheter (Geo-Map) allows for quicker acquisition of a large number of points and better definition of anatomy, but it is not validated for substrate mapping.


OBJECTIVE
This study evaluates the feasibility and accuracy of Geo-Map.


METHODS
Thirteen patients (mean age 38 +/- 12 years) with RV arrhythmias and an apparently normal heart underwent cardiac magnetic resonance imaging (MRI), Pt-Map, and Geo-Map. The 2 maps were compared in terms of mapping procedural time, radiation time, and total number of points acquired. We finally compared the number and characteristics of low-potential areas on each patient's Pt-Map, Geo-Map, and cardiac MRI.


RESULTS
Geo-Map required significantly shorter mapping and radiation times in comparison to Pt-Map (12.4 +/- 4.6 vs. 31.9 +/- 10.1 and 5.8 +/- 2.1 vs. 12.1 +/- 3.9, P <.001). Furthermore, Geo-Map was based on a significantly higher density of points in comparison to Pt-Map (802 +/- 205 vs. 194 +/- 38, P <.001). Taking into consideration the total number of RV regions analyzed, the Pt-Map and Geo-Map disagreed in 2 of 65 (3%) regions (P = NS), which only Geo-Map identified as low-potential areas and indeed corresponded to wall motion abnormalities on MRI.


CONCLUSIONS
Voltage maps obtained through RV geometry acquisition have accuracy comparable to that of conventional point-by-point mapping in detecting low-voltage areas, have a good correlation with MRI wall motion abnormalities, and allow a significant reduction in procedural time and x-ray exposure.
Cardiac Arrhythmia and Heart Failure Research Center, Catholic University of the Sacred Heart, San Camillo-Forlanini Hospital, Rome, Italy. michelacasella@hotmail.com
Michela
M
Casella
Francesco
F
Perna
Antonio
A
Dello Russo
Gemma
G
Pelargonio
Stefano
S
Bartoletti
Annalisa
A
Ricco
Tommaso
T
Sanna
Maurizio
M
Pieroni
Giovanni
G
Forleo
Augusto
A
Pappalardo
Luigi
L
Di Biase
Luigi
L
Natale
Fulvio
F
Bellocci
Paolo
P
Zecchi
Andrea
A
Natale
Claudio
C
Tondo
D000328:Adult; D001145:Arrhythmias, Cardiac / Q000175:diagnosis*; D018780:Body Surface Potential Mapping / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000295:instrumentation* / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D006352:Heart Ventricles; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged