These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Temporal heterogeneity of regional pulmonary perfusion is spatially clustered.
    Author: Glenny RW, Polissar NL, McKinney S, Robertson HT.
    Journal: J Appl Physiol (1985); 1995 Sep; 79(3):986-1001. PubMed ID: 8567543.
    Abstract:
    This study investigates temporal changes in regional pulmonary perfusion. Five dogs were studied with five or six different radiolabeled microspheres being injected via a central vein over 30 s every 20 min. The lungs of each animal were cubed into 1.9 cm3 pieces with spatial coordinates noted for each piece. Within individual pieces, the coefficient of variation of regional perfusion over time was 17.2 +/- 6.8% (SD) and across dogs accounted for 7.26 +/- 5.7% of total perfusion heterogeneity. Temporal variability or "twinkling" was not random. When lung pieces with similar temporal flow patterns were grouped together (regardless of spatial location), groups were more tightly clustered in space than expected by chance. Statistical clustering methods revealed regulation of blood flow on a large scale (lobar arteries), and fractal analyses suggested regulation existed on a smaller scale (arterioles). We conclude that regional pulmonary perfusion is heterogeneous over time in a nonrandom pattern and that pieces clustered by temporal patterns of perfusion are neighbors in the spatial domain.
    [Abstract] [Full Text] [Related] [New Search]