title: Reduced cardiac volumes in chronic fatigue syndrome associate with plasma volume but not length of disease: a cohort study.
abstract: To explore potential mechanisms that underpin the cardiac abnormalities seen in chronic fatigue syndrome (CFS) using non-invasive cardiac impedance, red cell mass and plasma volume measurements.
  
  
  
  Cardiac MR (MR) examinations were performed using 3 T Philips Intera Achieva scanner (Best, NL) in participants with CFS (Fukuda; n=47) and matched case-by-case controls. Total volume (TV), red cell volume (RCV) and plasma volume (PV) measurements were performed (41 CFS and 10 controls) using the indicator dilution technique using simultaneous 51-chromium labelling of red blood cells and 125-iodine labelling of serum albumin.
  
  
  
  The CFS group length of history (mean±SD) was 14±10 years. Patients with CFS had significantly reduced end-systolic and end-diastolic volumes together with reduced end-diastolic wall masses (all p<0.0001). Mean±SD RCV was 1565±443 mL with 26/41 (63%) having values below 95% of expected. PV was 2659±529 mL with 13/41 (32%) <95% expected. There were strong positive correlations between TV, RCV and PV and cardiac end-diastolic wall mass (all p<0.0001; r(2)=0.5). Increasing fatigue severity correlated negatively with lower PV (p=0.04; r(2)=0.2). There were no relationships between any MR or volume measurements and length of history, suggesting that deconditioning was unlikely to be the cause of these abnormalities.
  
  
  
  This study confirms an association between reduced cardiac volumes and blood volume in CFS. Lack of relationship between length of disease, cardiac and plasma volumes suggests findings are not secondary to deconditioning. The relationship between plasma volume and severity of fatigue symptoms suggests a potential therapeutic target in CFS.
authors.affiliation: Institute of Cellular Medicine, Newcastle upon Tyne, UK; Newcastle University, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: Julia L
authors.initials: JL
authors.lastname: Newton
authors.affiliation: Institute of Cellular Medicine, Newcastle upon Tyne, UK; Newcastle Magnetic Resonance Centre, Newcastle upon Tyne, UK.
authors.forename: Andreas
authors.initials: A
authors.lastname: Finkelmeyer
authors.affiliation: Newcastle University, Newcastle upon Tyne Hospitals NHS Foundation Trust , Newcastle upon Tyne , UK.
authors.forename: George
authors.initials: G
authors.lastname: Petrides
authors.affiliation: Institute of Cellular Medicine, Newcastle upon Tyne, UK; Newcastle University, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: James
authors.initials: J
authors.lastname: Frith
authors.affiliation: Newcastle Magnetic Resonance Centre , Newcastle upon Tyne , UK.
authors.forename: Tim
authors.initials: T
authors.lastname: Hodgson
authors.affiliation: Institute of Cellular Medicine , Newcastle upon Tyne , UK.
authors.forename: Laura
authors.initials: L
authors.lastname: Maclachlan
authors.affiliation: Institute of Cellular Medicine, Newcastle upon Tyne, UK; Newcastle University, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
authors.forename: Guy
authors.initials: G
authors.lastname: MacGowan
authors.affiliation: Institute of Cellular Medicine, Newcastle upon Tyne, UK; Newcastle Magnetic Resonance Centre, Newcastle upon Tyne, UK.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Blamire
keywords: AUTONOMIC NERVOUS SYSTEM; QUALITY OF CARE AND OUTCOMES