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Background: ADAS-3D software elaborates cardiac magnetic resonance (CMR) images to obtain a quantitative evaluation of dense scar and border zone (BZ), including BZ channels, which can be useful for ventricular tachycardia ablation and risk stratification. However, most prior reports with ADAS-3D used flexible thresholds (60% ± 5% and 40% ± 5% of maximum pixel signal intensity) to define dense scar and BZ. The impact of such variations of the threshold values on the measurements obtained with ADAS-3D is unknown., Objective: This study aimed to quantify the degree of change in ADAS-3D measurements when different thresholds for dense scar and BZ are employed., Methods: A single-center retrospective observational cohort study including 87 consecutive patients with previous myocardial infarction who underwent CMR was conducted. ADAS-3D software semiautomatically processed CMR sequences. We compared the scar measurements obtained with the 9 possible combinations of thresholds (55%/60%/65% and 35%/40%/45% of maximum pixel signal intensity)., Results: The overall comparison between thresholds showed highly significant differences (P < .001) in all scar parameters. Not a single patient maintained the same number of BZ channels with all the thresholds settings. A percentage difference of up to 200% in BZ channel numbers and channel mass was observed in all 36 comparisons. An absolute difference of up to 10 channels was also recorded. Of note, the highest median channel mass (obtained with the thresholds 35-65) was 59-fold higher compared with the lowest one (obtained with the 45-55 cutoffs)., Conclusion: Variations in threshold values result in statistically significant and high-magnitude changes in the quantification of scar parameters by ADAS-3D., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Introduction: Right ventricular (RV) pacing can impair left ventricular function and cause heart failure, known as pacing-induced cardiomyopathy (PICM). Upgrade to cardiac resynchronization (CRT) is its usual treatment; recently left bundle branch area pacing (LBBAP) has emerged as a potential alternative. Deep septal pacing (DSP), a simplified alternative to LBBAP, is still able to achieve narrower paced QRS than during conventional RV pacing. The aim of this study was to assess the effect of DSP in a cohort of patients with PICM., Methods and Results: Consecutive patients diagnosed with PICM were included. The aim was to upgrade patients to DSP. The procedure was considered successful if a paced QRS duration ≤140 ms was obtained, in the absence of a terminal R wave in V1. Twelve patients were included. The mean baseline LVEF was 33% (SD 4%), and the mean percentage of RV pacing was 99% (SD 1%). All patients had symptomatic heart failure. The mean paced QRS duration was 172 ms (SD 14 ms) with RV pacing, and 130 ms (SD 7 ms) with DSP (mean difference 42 ms, p < 0.001). At 6 months, the mean LVEF after the upgrade was 46% (SD 9%), significantly superior to LVEF with RV pacing (p = 0.001), a mean improvement of 13% (SD 10%). All patients except one experienced an improvement in LVEF of at least 5%., Conclusions: Our data suggest that DSP may be an effective and simpler alternative to biventricular or LBBAP in patients with PICM. Narrower paced QRS complexes can be achieved, which may lead to an improvement in left ventricular function., (© 2024 Wiley Periodicals LLC.)