Maintenance of Atrial Fibrillation

Three‐dimensional Integrated Functional, Structural, and Computational Mapping to Define the Structural “Fingerprints” of Heart‐Specific Atrial Fibrillation Drivers in Human Heart Ex Vivo

“…Since the early 20th century when Lewis et al31 proposed that a single reentry could sustain and drive AF, many explanations have been suggested for the mechanisms driving AF as we have recently reviewed 7. However, most studies accept the importance of atrial structure, and all mechanisms would benefit from a method that can quantify the contribution of atrial structural substrates to AF maintenance 32, 33, 34, 35, 36, 37, 38, 39.…”

“…Current ablation strategies for persistent/permanent AF or AF with concurrent cardiac diseases are disappointing, with a <30% long‐term success rate for single‐ablation procedures 1, 2, 3. This inadequate success rate may be because of the lack of basic understanding of the underlying atrial functional and structural substrates that sustain AF directly in human hearts4, 5, 6, 7 and emphasizes the need for quantitative tools to evaluate human atrial 3‐dimensional (3D) structural features in both clinical and experimental settings.…”

“…It has been suggested that AF may be driven by discrete reentrant drivers,6, 7, 8 ablation of which could treat the arrhythmia. However, current clinical structural imaging, including late gadolinium–enhanced MRI9, and electrode mapping approaches, lack the necessary resolution to resolve the defining structural–functional characteristics or “fingerprints” of AF drivers, including but not limited to transmural arrhythmogenic fibrosis, wall thickness variations, and myofiber misalignment 6, 7, 8.…”

“…However, current clinical structural imaging, including late gadolinium–enhanced MRI9, and electrode mapping approaches, lack the necessary resolution to resolve the defining structural–functional characteristics or “fingerprints” of AF drivers, including but not limited to transmural arrhythmogenic fibrosis, wall thickness variations, and myofiber misalignment 6, 7, 8. To date, there are no tools available to systematically analyze important structural characteristics, such as fibrosis distribution patterns, myofiber orientations, and wall thickness, across both atrial chambers in the human heart because of the inherent complexity of the atrial wall and the low resolution of current clinical imaging technology 10, 11, 12, 13, 14…”

“…However, the interspecies difference in atrial structure and physiology may diminish the translational applications of these models to human AF 7. The first realistic human atrial structural model was developed from cryosection images with a spatial resolution of 330 μm 3 of a deceased 59‐year‐old woman, but the model only included fiber orientations that were limited to major muscular bundles and lacked information on fibrosis 10.…”