Integration of MR images with electroanatomical maps: feasibility and utility in guiding left ventricular substrate mapping.
OBJECTIVE
The purpose of the study is to evaluate the feasibility and utility of magnetic resonance (MR) image and electroanatomic (EA) maps integration in guiding detailed left ventricle (LV) anatomical and substrate mapping, identifying the most accurate registration strategy.


METHODS
Twenty-five patients with dilated ischemic or non-ischemic cardiomyopathy were enrolled. We first verified the feasibility and accuracy of EA mapping and MR image integration using four different strategies (15 patients). Different EA maps were performed according to the strategy in exam: aortic map, collected from the descending portion of the arch to the ascending one; partial or complete LV map, reconstructed with a minimum of 40 widely distributed points or 200 points, respectively. We then evaluated the utility in LV substrate mapping of the most accurate integration method identified (ten patients).


RESULTS
Strategy III, based on aortic map and a partial LV map, allowed us to obtain an accurate integration with MR images of aorta and LV with a lower number of EA LV points; we therefore used this strategy during phase II of the study. Both mean LV end diastolic volume and long- and short-axis LV end diastolic diameters obtained by MR were not significantly different compared with Carto measurements. Eighty-eight percent of the segments with transmural/subendocardial scar detected by delayed enhanced MR were localized on bipolar voltage maps projected on MR-integrated images.


CONCLUSIONS
This study shows that integration strategy III represents the optimal registration method. Its clinical utility consists on guiding the catheter roving inside the chamber, mapping all areas of the LV and optimizing scar reconstruction.
Department of Cardiology, San Filippo Neri Hospital, Via Martinotti 20, 00135 Rome, Italy.
Claudio
C
Pandozi
Serena
S
Dottori
Carlo
C
Lavalle
Sabina
S
Ficili
Marco
M
Galeazzi
Maurizio
M
Russo
Angela
A
Pandozi
Giovanni
G
Camastra
Gerardo
G
Ansalone
Massimo
M
Santini
D000368:Aged; D000704:Analysis of Variance; D009202:Cardiomyopathies / Q000503:physiopathology* / Q000601:surgery; D017115:Catheter Ablation; D003287:Contrast Media; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D005471:Fluoroscopy; D019786:Gadolinium DTPA; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology* / Q000601:surgery
D003287:Contrast Media; D019786:Gadolinium DTPA