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Capillary supply to the sinus node in subjects with long-term atrial fibrillation

Aquilino Hurlé1, Damián Sánchez-Quintana, Siew Y Ho

  • 1Department of Cardiac Surgery, Hospital General Universitario de Alicante, Alicante, Spain. hurle_aqu@gva.es

The Annals of Thoracic Surgery
|January 28, 2010
PubMed

Insights

This study found significantly fewer capillaries in the sinus node of hearts with chronic atrial fibrillation, suggesting sinus node ischemia may contribute to this condition.

Area of Science:

  • Cardiovascular Research
  • Pathophysiology
  • Histology

Background:

  • Atrial ischemia, particularly of the sinus node, is implicated in atrial fibrillation pathogenesis.
  • This study investigated sinus node capillary differences between normal and chronically fibrillating hearts.

Purpose of the Study:

  • To compare sinus node blood capillary content and ultrastructure in normal hearts versus hearts with chronic atrial fibrillation.
  • To analyze the morphometric and ultrastructural features of sinus node capillaries in these two groups.

Main Methods:

  • Sinus node biopsies from 16 patients with chronic atrial fibrillation and 7 control subjects.
  • Analysis included immunohistochemistry, light microscopy, and transmission electron microscopy.
  • Morphometric techniques were used to quantify blood vessel density and capillary dimensions.

Main Results:

  • Blood vessel density (capillary proportion) was significantly lower in the atrial fibrillation group (1.06%) compared to controls (2.12%).
  • Internal and external capillary diameters showed non-significant trends towards smaller sizes in the atrial fibrillation group.
  • Ultrastructural analysis revealed scarce myoendocardial bridges and abnormal elastic fiber deposits in atrial fibrillation specimens.

Conclusions:

  • A significant reduction in sinus node capillaries exists in chronic atrial fibrillation.
  • These findings support a link between sinus node ischemia and the development of chronic atrial fibrillation.
Abstract

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