{
  "id": 10458251,
  "title": "Fibrosis burden and spatial pattern affect left atrial appendage stasis in multi-beat multi-physics simulations",
  "url": "https://urgent.news/2026/09/28/fibrosis-burden-and-spatial-pattern-affect-left-atrial-appendage",
  "topic": "culture",
  "section": "Culture",
  "published": "2026-09-28T00:00:00.000Z",
  "source": {
    "name": "bioRxiv",
    "slug": "biorxiv",
    "url": "https://www.biorxiv.org/content/10.64898/2026.09.26.754330v1?rss=1"
  },
  "original_language": "en",
  "account": "Atrial fibrosis can increase the risk of blood clots forming in the heart's left atrium and appendage. However, how fibrosis affects blood flow and transport in these chambers is not fully understood. Previous studies using physics-based models that combined electromechanical and fluid dynamics simulations matched the LA size to the actual anatomy but did not account for the varying locations of fibrosis within the LA and LAA.\n\nThis study used simulations of the common LA geometry, modeling how different patterns of fibrosis, both overall and localized to the LAA, impacted long-term hemodynamics in the chambers. Three fibrosis patterns were derived from late gadolinium enhancement MRI scans of patients with atrial fibrillation. Two patterns were applied uniformly across the LA at different overall fibrosis burdens of 15.6% and 31.2%. The remaining six cases had fibrosis confined to the LAA at three local burdens of 10%, 25%, and 50%.\n\nThe simulations revealed that while overall LA and LAA function was preserved with increasing fibrosis burden, the chamber-specific emptying fraction and kinetic energy decreased, while the time blood spent in the LA increased. The relationship between LA kinetic energy and emptying fraction was roughly quadratic, but the LAA case showed a more complex, non-monotonic pattern. Importantly, the spatial distribution of fibrosis had a significant independent effect on LAA blood stasis beyond what could be predicted from the overall emptying fraction alone.\n\nThese findings suggest that both the overall amount of fibrosis and its specific location within the LA and LAA play distinct roles in shaping the chambers' hemodynamics. The LAA's blood stasis, in particular, is influenced more by the spatial pattern of fibrosis than by the overall emptying fraction. Therefore, assessing imaging-derived fibrosis patterns, rather than just overall burden, could provide a more comprehensive assessment of thrombogenic risk in the LAA when making clinical decisions.",
  "summary": "Purpose: Atrial fibrosis is associated with thromboembolic risk in atrial fibrillation, but how fibrosis-related contractile impairment alters blood transport in the left atrium (LA) and left atrial appendage (LAA) remains unclear. Prior multi-physics simulations coupled electromechanical (EM) and computational fluid dynamics (CFD) models to show that fibrosis impairs LA function and flow, but…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}