ISSN 2996-8215
International Journal of Cardiology | Vol. 10, No. 7, July 2019 | pp. 49–56
DOI: 10.46882/2019/IJC/000124
Original Research Article
Diagnostic Precision of High-Resolution 3D Late Gadolinium Enhancement CMR for the Identification of Left Atrial Conduction Gaps Post-Cryoballoon Ablation
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:
Cryoballoon catheter ablation successfully isolates the pulmonary veins in paroxysmal atrial fibrillation (AF), but recurrent tachyarrhythmias arise if incomplete scar sets leave linear conduction gaps. Non-invasive mapping of thin left atrial (LA) scars requires optimized high-spatial-resolution sequencing to plan revision procedures. This study evaluated the diagnostic precision of high-resolution 3D late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) for identifying pulmonary vein scar discontinuity, using electroanatomical voltage mapping (EAM) as the reference standard. We prospectively evaluated 52 patients with recurrent atrial tachyarrhythmias scheduled for a secondary ablation procedure who underwent pre-procedural 3D LGE CMR (1.3 mm isotropic voxel size). Left atrial walls were segmentally partitioned and thresholded to isolate scars at 3 standard deviations above healthy tissue. Segmental scar footprints were registered into intraprocedural 3D EAM matrices. On a segment-by-segment analysis (416 total sections), high-resolution 3D LGE CMR identified conduction gaps with a sensitivity of 86.4% (95% CI: 77.2%–92.8%), a specificity of 89.6% (95% CI: 82.3%–94.7%), and an overall diagnostic accuracy of 88.5%. The total computed circumference of circumscribed PVI scar patterns matched low-voltage areas on EAM maps (r = 0.82, p < 0.001). No severe contrast-related side effects were reported. High-resolution isotropic 3D late gadolinium enhancement CMR demonstrates excellent diagnostic precision for identifying left atrial scar gaps, offering a robust non-invasive method to localize conduction breaches prior to repeat ablation interventions.
Keywords: Atrial fibrillation, Cryoballoon ablation, Cardiac magnetic resonance, Late gadolinium enhancement, Left atrium, Electroanatomical mapping
Received: April 02, 2019; Revised: May 15, 2019; Accepted: June 08, 2019; Published: July 22, 2019