Tag: blood pressure

Autonomic function in patients with chronic fatigue syndrome

Abstract:

Subtle signs of autonomic dysfunction and orthostatic intolerance have been reported in patients with chronic fatigue syndrome (CFS). To assess cardiovascular autonomic function noninvasively in an unselected group of patients with CFS, we examined responsiveness to several cardiovascular reflex tests in 37 CFS patients and 38 healthy control subjects.

Blood pressure and heart rate (HR) were recorded continuously by a Finapres device before and during forced breathing, standing up, Valsalva maneuver, and sustained handgrip exercise (HG). In addition, a mental arithmetic test was carried out and questionnaires to assess the severity of CFS symptoms were completed.

At rest, there were no significant differences in blood pressure or in HR between the two groups. The in- and expiratory difference in HR tended to be lower in CFS patients (28.4 +/- 10.5 beats) than in healthy controls (32.2 +/- 9.5) (p = 0.11). The maximal increase in HR during standing up was not significantly different between the CFS group (37.6 +/-8.9 beats) and the control group (40.2 +/- 8.9 beats). There were no significant differences between both groups with regard to the Valsalva ratio, but the systolic and diastolic blood pressure responses were significantly larger in CFS patients, despite the fact that many CFS patients were not able to sustain the Valsalva maneuver. The HR response to MA was significantly less in the CFS group (22.6 +/- 9.9) than in the control group (29.5 +/- 16.7) (p < 0.05), suggesting impaired cardiac sympathetic responsiveness to mental stress. The lower HR responses could not be explained by the level of concentration in the CFS group.

During HG exercise, the hemodynamic responses were lower in the CFS group than in the control group, but this might be attributed to the lower level of muscle exertion in CFS patients. There were no significant differences between CFS patients with and without symptoms of autonomic dysfunction regarding the hemodynamic responses to the cardiovascular reflex tests. The findings of the study suggest that there are no gross alterations in cardiovascular autonomic function in patients with CFS.

 

Source: Soetekouw PM, Lenders JW, Bleijenberg G, Thien T, van der Meer JW. Autonomic function in patients with chronic fatigue syndrome. Clin Auton Res. 1999 Dec;9(6):334-40. http://www.ncbi.nlm.nih.gov/pubmed/10638807

 

Chronic fatigue syndrome: a hypothesis focusing on the autonomic nervous system

Abstract:

Chronic fatigue syndrome is a debilitating illness of unknown aetiology, with estimated levels of prevalence of up to about 8. 7/100 000 in the U.S.A. Like pain fatigue it is a personal, emotionally rich experience, which may originate from peripheral or central sites (or both). The nature of the symptoms is complex and reflects the interaction of the patient with the environment and cultural milieu. Accordingly the common use of the same terminology for different types of fatigue may be misleading.

Autonomic activation is a key component of both real and simulated physical exercise. Alterations in autonomic nervous system activity are a key component of several physiopathological conditions. In chronic fatigue syndrome disturbances in autonomic activity, and in other homoeostatic mechanisms, such as the hormonal and immune systems, have been reported recently.

In this review we followed the hypothesis that in chronic fatigue syndrome the paradoxical condition of disturbing somatic symptoms in the absence of organic evidence of disease might be addressed by focusing on attending functional correlates. In particular we addressed possible alterations in cardiovascular autonomic control, as can be assessed by spectral analysis of R-R interval and systolic arterial pressure variability.

With this approach, in subjects complaining of unexplained fatigue, we obtained data suggesting a condition of prevailing sympathetic modulation of the sino-atrial node at rest, and reduced responsiveness to excitatory stimuli. Far from considering the issue resolved, we propose that in the context of the multiple physiological and psychological interactions involved in the perception and self-reporting of symptoms, attendant changes in physiological equivalents might furnish a convenient assessment independent from subjective components.

Indices of sympathetic modulation could, accordingly, provide quantifiable signs of the interaction between subject’s efforts and environmental demands, independently of self descriptions, which could provide convenient measurable outcomes, both for diagnosis and treatment titration in chronic fatigue syndrome.

Comment in: Long- and short-term blood pressure and RR-interval variability and psychosomatic distress in chronic fatigue syndrome. [Clin Sci (Lond). 1999]

 

Source: Pagani M, Lucini D. Chronic fatigue syndrome: a hypothesis focusing on the autonomic nervous system. Clin Sci (Lond). 1999 Jan;96(1):117-25. http://www.ncbi.nlm.nih.gov/pubmed/9857114

 

No strong evidence of disturbed regulation of blood pressure in chronic fatigue syndrome

Abstract:

Recent medical publications postulate a connection between the Chronic Fatigue Syndrome (CFS) and disturbed regulation of the circulation, manifesting itself during orthostatic stress testing.

Four studies were published on the circulatory response on prolonged head up tilt testing. Numerous CFS patients displayed postural tachycardia or syncope during the test. However, many CFS patients examined had had orthostatic symptoms prior to the examination.

It is not certain that cardiovascular dysregulation is present in CFS patients without orthostatic symptoms. It is also not clear whether such a dysregulation would be the effect of physical inactivity or a manifestation of a subtle form of autonomic neuropathy.

 

Source: Smit AA, Bolweg NM, Lenders JW, Wieling W. No strong evidence of disturbed regulation of blood pressure in chronic fatigue syndrome. Ned Tijdschr Geneeskd. 1998 Mar 21;142(12):625-8.[Article in Dutch] http://www.ncbi.nlm.nih.gov/pubmed/9623125

 

Long- and short-term blood pressure and RR-interval variability and psychosomatic distress in chronic fatigue syndrome

Abstract:

1. Chronic low blood pressure has been associated with fatigue and low mood. However, in the chronic fatigue syndrome (CFS) the blood pressure (BP) and heart rate profile and their variabilities have not been characterized as yet.

2. We performed office and 24 h ambulatory BP recordings in 38 subjects (age, 34.8 +/- 8.0 years) who fulfilled the Holmes criteria for CFS and in 38 healthy control subjects (age 35.6 +/- 10.5 years), as well as short-term beat-to-beat BP and RR-interval recordings for 10 min in supine and standing position, and calculated spectral indices.

3. In CFS office (123 +/- 19/70 +/- 12 mmHg) as well as 24-h, day- and night-time blood pressure values (116 +/- 11.1/71 +/- 11.1, 121 +/- 9.2/77 +/- 8.0 and 110 +/- 10.5/65 +/- 9.2 mmHg respectively) were within reference limits.

4. Heart rate was consistently higher (P < 0.01) in CFS patients, based on both office (77 +/- 12 compared with 68 +/- 12 beats min-1) and 24 h ambulatory recordings (77 +/- 12 compared with 67 +/- 15 beats min-1).

5. In supine position, spectral indices of BP variability (total, low-frequency and high-frequency variances) were all significantly (P < 0.01) lower in CFS. In standing position the differences disappeared. Analysis of RR-interval variability could not detect major alterations in autonomic function in CFS.

Comment in: Long- and short-term blood pressure and RR-interval variability and psychosomatic distress in chronic fatigue syndrome. [Clin Sci (Lond). 1999]

 

Source: Duprez DA, De Buyzere ML, Drieghe B, Vanhaverbeke F, Taes Y, Michielsen W, Clement DL. Long- and short-term blood pressure and RR-interval variability and psychosomatic distress in chronic fatigue syndrome. Clin Sci (Lond). 1998 Jan;94(1):57-63. http://www.ncbi.nlm.nih.gov/pubmed/9505867