title: Coronary microcirculation remodeling in patients with idiopathic dilated cardiomyopathy.
abstract: BACKGROUND
  In patients with idiopathic dilated cardiomyopathy (IDCM), the myocardial blood flow is markedly depressed. The presence of alterations in the number and length of the coronary microcirculation has not been explored.
  
  
  METHODS
  In explanted hearts of 6 patients with IDCM and in 6 normal control hearts, the arteriolar length density and capillary numerical density were determined in sections stained with orcein (vessels 50-200 μm in diameter), for smooth muscle actin (vessels 6-50 μm in diameter) and CD34 (capillaries).
  
  
  RESULTS
  No difference with normal hearts was observed in capillary numerical density and in length density of vessels above 50 μm in diameter. In IDCM, more than 50% of arterioles below 50 μm in diameter displayed an incomplete smooth muscle wall, and length density, especially for arterioles between 6 and 20 μm in diameter, was significantly lower (42.84 ± 8.51 mm/mm(3)) than in controls (75.34 ± 3.05 mm/mm(3), p = 0.001).
  
  
  CONCLUSIONS
  In IDCM, arterioles below 50 μm in diameter display an incomplete smooth muscle wall and a significant decrease in length density. These observations provide an anatomical basis for a decreased coronary flow reserve in IDCM.
authors: Department of Pathology, University Hospital Favaloro Foundation, Buenos Aires, Argentina.
authors: Rubén
authors: R
authors: Laguens
authors: Paulino
authors: P
authors: Alvarez
authors: Carlos
authors: C
authors: Vigliano
authors: Patricia
authors: P
authors: Cabeza Meckert
authors: Liliana
authors: L
authors: Favaloro
authors: Mirta
authors: M
authors: Diez
authors: Roberto
authors: R
authors: Favaloro
mesh_terms: D000293:Adolescent; D000328:Adult; D001160:Arterioles / Q000473:pathology; D002311:Cardiomyopathy, Dilated / Q000473:pathology / Q000503:physiopathology*; D016022:Case-Control Studies; D003326:Coronary Circulation / Q000502:physiology*; D003327:Coronary Disease / Q000473:pathology / Q000503:physiopathology*; D003331:Coronary Vessels / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008833:Microcirculation / Q000502:physiology*; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology; D055815:Young Adult