Po-03-100 a validation study of the accuracy of the atrial pace map assessed with intracardiac pattern matching: potential utility of non-pulmonary vein mapping

The elimination of all non-PV triggers is known to be an additional strategy for the PVI of AF. However, activation mapping of infrequent non-PV triggers is challenging. We hypothesized that pace mapping assessed by intracardiac pattern matching (ICPM) with the CARTO3 mapping system yields a good diagnostic performance to locate atrial premature complexes (APCs). Furthermore, we assessed whether the combined use of both atrial electrograms for the ICPM improved the accuracy as compared to using electrograms only in the LA. In 16 patients, atrial pacing at 21 sites (LA anterior: 5, LA posterior: 8, LA septum: 3, and RA lateral: 5) was arbitrarily determined as APC foci, and the intracardiac atrial sequence of the obtained APC was set as a reference. The matching ICPM score was assessed during pace mapping around the APC focus. ICPM was determined by CS electrograms (CS group) or those from both the CS and RA (CS-RA group). The surface area was measured for each matching score. The mean pace mapping number was 213±113 points and was similar between the CS and CS-RA groups (181±81 vs. 237±114 points, P=0.09). By pace mapping with ICPM, maximum matching scores of ≥90% were obtained at all pacing origins in both the CS and CS-RA groups. At least 1 site with a matching score ≥98% was more often obtained in the CS group than CS-RA group (14/21 APCs [67%] vs. 7/21 APCs [33%], P=0.03), but sites with matching scores ≥95% were similarly obtained between the CS and CS-RA groups (17/21 APCs [81%] vs. 19/21 APCs [90%], P=0.66). The sites with matching scores ≥90% were all APCs in both groups. The surface area of matching scores ≥98% was similar between the CS and CS-RA groups (0.2 [0.1, 1.3] vs. 0.35 [0.1, 5.5] cm2, P=0.23), but that ≥95% was smaller in the CS-RA group than CS group (0.2 [0.1, 0.4] vs. 0.6 [0.15, 4.8] cm2, P=0.03). Of LA origins, the surface area for matching scores ≥95% was equal between the CS and CS-RA groups (0.2 [0.1, 0.5] vs. 0.5 [0.1, 1.3] cm2, P=0.19), but for RA origins, it was smaller in the CS-RA group than CS group (0.2 [0.1, 2.3] vs. 8 [0.3, 13.0] cm2, P=0.05) (Figure). ICPM-guided pace mapping may be useful to locate infrequent non-PV APCs. A combined use of RA and CS electrograms may improve the mapping quality and may be essential for identifying origins of RA non-PV APCs. RF applications targeting the area with a matching score ≥95% may be reasonable for a non-PV trigger ablation.