Impaired cardiovascular response to standing in Chronic Fatigue Syndrome
Article first published online: 23 MAY 2010
© 2010 The Authors. Journal Compilation © 2010 Stichting European Society for Clinical Investigation Journal Foundation
European Journal of Clinical Investigation
Volume 40, Issue 7, pages 608–615, July 2010
How to Cite
Hollingsworth, K. G., Jones, D. E. J., Taylor, R., Blamire, A. M. and Newton, J. L. (2010), Impaired cardiovascular response to standing in Chronic Fatigue Syndrome. European Journal of Clinical Investigation, 40: 608–615. doi: 10.1111/j.1365-2362.2010.02310.x
- Issue published online: 9 JUN 2010
- Article first published online: 23 MAY 2010
- Received 13 January 2010; accepted 9 April 2010
- Cardiac function;
Eur J Clin Invest 2010; 40 (7): 608–615
Background Impaired skeletal muscle metabolism is recognized in chronic fatigue syndrome (CFS). This study examined the relationship between skeletal and cardiac muscle function and symptoms on standing in CFS using magnetic resonance spectroscopy (MRS) and impedance cardiography.
Materials and methods Phosphocreatine (PCr)/adenosine triphosphate (ATP) ratio by cardiac MRS, PCr/ADP and proton efflux by muscle MRS were performed in 12 CFS (Fukuda) and 8 controls. Head up tilt (HUT) and cardiac contractility (left ventricular work index, LVWI) (n = 64 CFS and matched controls) were found. Fatigue impact was accessed by Fatigue Impact Scale and orthostatic symptoms by Orthostatic Grading Scale (OGS).
Results Cardiac PCr/ATP correlated with measures of muscle bioenergetic function (half-time PCr recovery [κ = −0·71, P = 0·005] and half-time ADP recovery [κ = −0·60, P = 0·02]) suggesting that the muscle and cardiac bioenergetic function correlate in CFS. Four of 12 (33·3%) CFS patients had PCr/ATP values consistent with significant cardiac impairment. Those with impaired cardiac energy metabolism had significantly reduced maximal and initial proton efflux rates (P < 0·05). Cardiac PCr/ATP ratio correlated with myocardial contractility (LVWI) in response to standing (P = 0·03). On HUT, LVWI on standing was significantly higher in CFS (P = 0·05) with symptoms on standing (OGS) occurring in 61/64 (95%) (vs. 25/64 [39%] controls; P < 0·0001). OGS scores were significantly higher in those with abnormal LVWI responses to standing (P = 0·04), with the LVWI on standing correlating with OGS scores (r2 = 0·1; P = 0·03). HUT was positive in 19 (32%).
Conclusions Skeletal muscle and cardiac bioenergetic abnormalities associate in CFS. Cardiac bioenergetic metabolism associates with increase in cardiac contractility on standing. Haemodynamic assessment in CFS is well tolerated and safe with a high diagnostic yield comparable with unexplained syncope.