Saturday, May 30, 2009

Blood Volume and Cardiac Insufficiency

http://bit.ly/11JSTA

  Clinical science (Lond). 2009 May 26.

  Chronic fatigue syndrome: illness severity,
  sedentary lifestyle, blood volume and
  evidence of diminished cardiac function.

  Hurwitz BE, Coryell VT, Parker M, Martin P,
  Laperriere A, Klimas NG, Sfakianakis GN, Bilsker MS.

  This study examined whether deficits in cardiac
  output and blood volume in a Chronic Fatigue
  Syndrome (CFS) cohort were present and linked to
  illness severity and sedentary lifestyle.

  Follow-up analyses assessed whether differences
  between CFS and control groups in cardiac output
  levels were corrected by controlling for cardiac
  contractility and total blood volume (TBV).

  The 146 participants were subdivided into two CFS
  groups based on symptom severity data, severe
  (n=30) vs. non-severe (n=26), and two healthy
  non-CFS control groups based on physical activity,
  sedentary (n=58) vs. non-sedentary (n=32).

  Controls were matched to CFS participants using age,
  sex, ethnicity and body mass.

  Echocardiographic measures indicated that the
  severe CFS participants displayed 10.2% lower
  cardiac volume (i.e., stroke index and end diastolic
  volume) and 25.1% lower contractility
(velocity of
  circumferential shortening corrected by heart rate)
  than the control groups.

  Dual tag blood volume assessments indicated that
  CFS groups had lower TBV, plasma volume (PV) and
  red blood cell volume (RBCV) than control groups.

  Of the CFS subjects with a TBV deficit (i.e., >/=8%
  below ideal levels), the mean +/-SD percent deficit
  in TBV, PV and RBCV were 15.4+/-4.0, 13.2+/-5.0,
  and 19.1+/-6.3, respectively.

  Lower CFS cardiac volume levels were substantially
  corrected by controlling for prevailing TBV deficits,
  but were not affected by controlling for cardiac
  contractility.

  Analyses indicated that the TBV deficit explained
  91-94% of the group differences in cardiac volume
  indices.

  Group differences in cardiac structure were offsetting
  and hence no differences emerged for LV mass index.

  Therefore, the findings indicate that lower cardiac
  volume levels, displayed primarily by persons with
  severe-CFS, were not linked to diminished cardiac
  contractility levels, but were likely a consequence of
  a comorbid hypovolemic condition.

  Further study is needed to address the extent to
  which the CFS cardiac and blood volume alterations
  have physiological and clinical significance.

  PMID: 19469714 [PubMed - as supplied by publisher]
 
 
 

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