doi:10.1016/j.hrthm.2021.05.023engB, JáureguiD, PenelaJ, Fernández-ArmentaJ, AcostaC, TerésD, Soto-IglesiasE, SilvaA, OrdóñezAntonio R, SanA, ChaucaJM, CarreñoC, SchererA, BerruezoImpact of a Pre-defined Pacemapping Protocol Use for Ablation of Infrequent Premature Ventricular Complexes: A Prospective, Multicenter Study.ART-2021-146814Background Pacemapping (PM) is a useful maneuver for aiding premature ventricular complex (PVC) ablation. Its standalone clinical value is still to be defined. Objectives The purpose of this study was to analyze the efficacy of a predefined PM protocol for low-burden PVC ablation, regardless of their site of origin (SOO) and the presence of structural heart disease. Methods This was a prospective, nonrandomized, multicenter study. The PM protocol was performed when <1 PVC/min was found. The “target area” was delimited by the 3 best matching points >94% correlation, and 3 radiofreqency (RF) applications were delivered. Results Of 185 patients, 105 (57%) underwent activation mapping, 60 (32%) were PM-guided, and 20 (11%) were canceled due to absence of PVCs. Baseline QRS, PVC burden, and outflow tract origin were independent predictors of PM-guided ablation. A higher proportion of right ventricular outflow tract SOO in the PM group (52% vs 40%; P = .03) was observed. Mean target area was 0.6 ± 0.9 cm2. Mean 10-ms isochronal area in local activation time (LAT)-guided procedures was higher (1.7 ± 2.3 cm2; P <.001). Mean number of PM matching points acquired was 39 ± 21 (range 6–98). Mean mapping and RF times were similar in both groups. However, significantly shorter procedural (53 ± 24 vs 61 ± 26 minutes; P = .04) as well as RF times (111 ± 51 vs 149 ± 149 seconds; P = .05) were needed in the PM group using the proposed protocol. Global clinical success reached 87% for the PM group and 90% (P = .58) the for LAT mapping group. Conclusion When LAT mapping is precluded, application of a PM-guided ablation protocol directed to >94% matching correlation target area is a more efficient alternative with comparable clinical results. ed to >94% matching correlation target area is a more efficient alternative with comparable clinical results.2021http://zaguan.unizar.es/record/16536510.1016/j.hrthm.2021.05.023http://zaguan.unizar.es/record/165365oai:zaguan.unizar.es:165365HEART RHYTHM 18, 10 (2021), 1709-1716by-nc-ndhttps://creativecommons.org/licenses/by-nc-nd/4.0/deed.esinfo:eu-repo/semantics/openAccess