• Am. J. Physiol. Heart Circ. Physiol. · Jan 2005

    Right atrial dimension-pressure relation during volume expansion is unaltered by pregnancy in the rat.

    • Tina Hines, Sarang S Abhyankar, and Jessica M Veeh.
    • University of Missouri Kansas City School of Nursing, 2220 Holmes St., Kansas City, MO 64108, USA. hinesmc@umkc.edu
    • Am. J. Physiol. Heart Circ. Physiol. 2005 Jan 1;288(1):H116-20.

    AbstractBlood volume expands significantly during pregnancy, but afferent signals from cardiac receptors are reduced. In addition, during exogenous volume expansion, right atrial pressure (RAP) increases more for equivalent volumes in pregnant animals, implying reduced atrial compliance. To examine possible gestational alterations in atrial dimension during volume expansion, we compared the effects of volume expansion on RAP and right atrial dimension (RAD) in pregnant vs. virgin rats. Anesthetized animals were ventilated and catheterized for measurement of arterial pressure and RAP and for drug infusion. Through a parasternal incision, ultrasonic crystals were glued to the medial and lateral surfaces of the right atrium for measurement of RAD. Plasma volume and hematocrit were determined before experimentation. RAP, RAD, and arterial pressure were recorded at baseline and during progressive volume expansion (6% dextran, 60% of initial blood volume). Baseline RAP was similar in the two groups: 2.82 +/- 0.40 and 2.72 +/- 0.47 mmHg in pregnant and virgin rats, respectively. Basal RAD was significantly larger in pregnant than in virgin rats: 4.36 +/- 0.66 vs. 3.36 +/- 0.48 mm. Despite increased basal RAD in pregnant rats, the slope of the RAD-RAP relation during volume expansion was similar in the two groups. Results indicate that resting RAD is increased in pregnant rats and that the change in dimension during volume loads is similar to that in virgin rats. Thus, during pregnancy, the right atrium appears to accommodate the increased blood volume, and reduced afferent signaling most likely is due to mechanisms other than mechanical alterations of the atrium by expanded volume.

      Pubmed     Free full text   Copy Citation     Plaintext  

      Add institutional full text...

    Notes

     
    Knowledge, pearl, summary or comment to share?
    300 characters remaining
    help        
    You can also include formatting, links, images and footnotes in your notes
    • Simple formatting can be added to notes, such as *italics*, _underline_ or **bold**.
    • Superscript can be denoted by <sup>text</sup> and subscript <sub>text</sub>.
    • Numbered or bulleted lists can be created using either numbered lines 1. 2. 3., hyphens - or asterisks *.
    • Links can be included with: [my link to pubmed](http://pubmed.com)
    • Images can be included with: ![alt text](https://bestmedicaljournal.com/study_graph.jpg "Image Title Text")
    • For footnotes use [^1](This is a footnote.) inline.
    • Or use an inline reference [^1] to refer to a longer footnote elseweher in the document [^1]: This is a long footnote..

    hide…