ISSN 2996-8215
International Journal of Cardiology | Vol. 17, No. 3, March 2026 | pp. 17–24
DOI: 10.46882/2026/IJC/000203
Original Research Article
Three-Dimensional Threshold Quantification of Fibrotic Gaps via Isotropic Macro-Aqueous Structural Mapping
David M. Ross¹, Sarah L. Jenkins¹, Richard G. Carter²
¹Department of Cardiovascular Imaging, The Alfred Hospital, Monash University, Melbourne, Victoria, Australia
²Division of Electrophysiology, Royal Melbourne Hospital, University of Melbourne, Melbourne, Victoria, Australia
Abstract:
Catheter ablation using pulmonary vein isolation (PVI) is an effective strategy for managing atrial fibrillation, but recurrent arrhythmia occurs due to gaps in procedural scar lines. Visualizing and quantifying thin left atrial (LA) myocardial scar tissue requires optimized high-spatial-resolution imaging. This study evaluated the diagnostic accuracy of a novel high-resolution 3D late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) sequence for identifying and quantifying LA scars, using electroanatomical voltage mapping (EAM) as the reference standard. We prospectively evaluated 45 patients with recurrent atrial tachyarrhythmias scheduled for a repeat ablation procedure who underwent 3D LGE CMR (1.3 mm isotropic resolution) within 48 hours prior to the intervention. Scars were quantified off-line using a threshold of 3 standard deviations above normal atrial myocardium. Atrial structures were merged with intraprocedural 3D EAM. On a segment-based analysis (432 segments total), high-resolution 3D LGE CMR demonstrated a diagnostic sensitivity of 88.4% (95% CI: 82.5%–92.8%) and a specificity of 91.2% (95% CI: 86.4%–94.7%) for detecting low-voltage scar zones (bipolar voltage less than 0.5 mV). The total quantified LA scar surface area correlated strongly with EAM scar maps (r = 0.84, p < 0.001). High-spatial-resolution 3D late gadolinium enhancement CMR provides excellent diagnostic accuracy for detecting left atrial scar tissue, facilitating non-invasive localization of conduction gaps before redo ablation procedures.
Keywords: Atrial fibrillation, Catheter ablation, Cardiac magnetic resonance, Late gadolinium enhancement, Left atrium, Electroanatomical mapping
Received: December 02, 2025; Revised: January 18, 2026; Accepted: February 08, 2026; Published: March 15, 2026