Clinical characteristics of a novel subgroup of chronic fatigue syndrome patients with postural orthostatic tachycardia syndrome
– Source: Journal of Internal Medicine, Dec 4, 2012
By I Lewis, J Newton, et al.
[Note: POTS is one of five types of orthostatic intolerance that collectively affect nearly all chronic fatigue syndrome (ME/CFS) patients, according to Dr. David Bell - see “Orthostatic Intolerance and Chronic Fatigue Syndrome.”]
Objectives: A significant proportion of patients with chronic fatigue syndrome (CFS) also have postural orthostatic tachycardia syndrome (POTS). We aimed to characterize these patients and differentiate them from CFS patients without POTS in terms of clinical and autonomic features.
Methods: A total of 179 patients with CFS (1994 Centers for Disease Control and Prevention criteria) attending one of the largest Department of Health-funded CFS clinical services were included in the study.
Outcome measures were:
1. Symptom assessment tools including the fatigue impact scale, Chalder fatigue scale, Epworth sleepiness scale (ESS), orthostatic grading scale (OGS) and hospital anxiety and depression scale (HADS-A and -D, respectively),
2. Autonomic function analysis including heart rate variability and
3. Hemodynamic responses including left ventricular ejection time and systolic blood pressure drop upon standing.
CFS patients with POTS (13%, n=24) were:
• Younger (29 +/- 12 vs. 42 +/- 13 years, P<0.0001) [probability the difference resulted by chance less than 1 in 10,000],
• Less fatigued (Chalder fatigue scale, 8 +/- 4 vs. 10 +/- 2, P=0.002),
• Less depressed (HADS-D, 6 +/- 4 vs. 9 +/- 4, P=0.01),
• And had reduced daytime hypersomnolence [hypersomnolence is excessive sleeping/sleepiness] (ESS, 7 +/- 6 vs. 10 +/- 5, P=0.02)…
…Compared with patients without POTS.
In addition, they exhibited greater orthostatic intolerance (OGS, 11 +/- 5; P<0.0001) and autonomic dysfunction.
A combined clinical assessment tool of Epworth sleepiness scale 9 or less and orthostatic grading scale 9 or more identifies accurately CFS patients with POTS with 100% positive and negative predictive values.
The presence of POTS marks a distinct clinical group of CFS patents, with phenotypic features differentiating them from those without POTS.
A combination of validated clinical assessment tools can determine which CFS patients have POTS with a high degree of accuracy, and thus potentially identify those who require further investigation and consideration for therapy to control heart rate.
Source: Journal of Internal Medicine, Dec 4, 2012. PMID:23206180, by Lewis I, Pairman J, Spickett G, Newton JL. Institute for Ageing & Health, Newcastle University, Newcastle, UK. [Email: firstname.lastname@example.org]