Accuracy of combined endocardial and epicardial electroanatomic mapping of a reperfused porcine infarct model: A comparison of electrofield and magnetic systems with histopathologic correlation

Background Contact mapping of the ventricle with NAVX has not been validated. Objective This study sought to compare the accuracy of infarct mapping between NAVX and CARTO using a histopathologic gold standard. Methods A closed-chest porcine infarction model was created by circumflex artery occlusion. After 4 to 12 weeks, 7 subjects underwent high-density endocardial and epicardial mapping using CARTO (Biosense Webster, Diamond Bar, California) and NAVX (St. Jude Medical, St. Paul, Minnesota) mapping systems. After mapping, animals were euthanized and histopathologic examination was used to quantify areas of scar at depths of 1 to 4 mm. Results Using a single-point acquisition approach with CARTO and a multipoint acquisition approach with the NAVX, endocardial and epicardial maps created using CARTO consisted of 360 ± 121 points performed in 54 ± 23 minutes/361 ± 90 points in 41 ± 13 minutes compared with 697 ± 132 points in 35 ± 8 minutes/1,303 ± 207 points in 30 ± 11 minutes using NAVX. At a 2-mm depth from the endocardial and epicardial surface, the mean scar area quantified by histopathology was 9.5 ± 8.7 cm² and 6.2 ± 4.8 cm², respectively. Correlation between histopathology and electroanatomic maps was excellent (r = 0.88, CARTO and 0.92, NAVX). Correlation between scar area determined by CARTO and NAVX was good (r = 0.88, P <.0001). Conclusion Balloon occlusion-reperfusion of the circumflex artery creates a localized patchy infarction in the inferolateral wall. Multipolar mapping achieves higher density in a shorter period of time and increases the detection of late potentials. A strong correlation between CARTO and NAVX exists, and both systems demonstrate good correlation with histopathologic quantification of scar.