Tag: orthostatic intolerance

Autonomic function and child chronic fatigue syndrome

Abstract:

It is postulated that child chronic fatigue syndrome (CFS) involves the autonomic nervous system, although the precise mechanism has not been clearly indicated. This paper reviews recent reports focusing the role of the autonomic nervous system which plays in CFS. Many of the method for measuring autonomic function have appeared in the clinical setting in parallel with advancing computer technology, but these are limited when applied in children. In these blood pressure and heart rate changes during orthostatic stress and these variability are favorably used. As a result, one third of children with CFS showed abnormal cardiovascular adjustment during posture change (orthostatic dysregulation: OD) which is characterized by instantaneous orhthostatic hypotension, postural tachycardia or neurally-mediated syncope. Most of the studies using power spectral analysis of heart rate variability showed sympathetic activation, however no consistent finding has been obtained. In conclusion, autonomic function might be partly involved in CFS such as OD, but its priority in causing CFS is unclear.

 

Source: Tanaka H. Autonomic function and child chronic fatigue syndrome. Nihon Rinsho. 2007 Jun;65(6):1105-12. [Article in Japanese] https://www.ncbi.nlm.nih.gov/pubmed/17561705

 

Treatment of chronic fatigue and orthostatic intolerance with propranolol

Abstract:

We describe the effect of propranolol in an adolescent with chronic fatigue syndrome and orthostatic intolerance. Our observations suggest that the head-up tilt-test and beta-blocker treatment might be considered in patients with chronic fatigue syndrome and that enhanced sympathetic nervous activity might be part of the underlying pathophysiology.

 

Source: Wyller VB, Thaulow E, Amlie JP. Treatment of chronic fatigue and orthostatic intolerance with propranolol. J Pediatr. 2007 Jun;150(6):654-5. https://www.ncbi.nlm.nih.gov/pubmed/17517256

 

Baroreceptor reflex and integrative stress responses in chronic fatigue syndrome

Abstract:

OBJECTIVE: Altered cardiovascular responses to mental and postural stressors have been reported in chronic fatigue syndrome (CFS). This study examined whether those findings may involve changes in baroreceptor reflex functioning.

METHODS: Chronotropic baroreceptor reflex (by sequential analysis) and cardiovascular stress responses were recorded during postural (5-minute of active standing) and cognitive (speech task) stress testing in patients with CFS grouped into cases with severe (N = 21) or less severe (N = 22) illness, and in 29 matched control subjects.

RESULTS: Patients with CFS had a greater decline in baroreceptor reflex sensitivity (BRS) during standing, although only those with severe CFS were significantly different from the controls. Systolic blood pressure declined during standing in the control group but was maintained in the CFS patients. In contrast, the patients with less severe CFS had blunted increases in blood pressure during the speech task, which could not, however, be explained by inadequate inhibition of the baroreceptor reflex, with all groups showing an appropriate reduction in BRS during the task.

CONCLUSIONS: These results indicate that in CFS, deficiencies in orthostatic regulation, but not in centrally mediated stress responses, may involve the baroreceptor reflex. This study also suggests that classifying patients with CFS on illness severity may discriminate between patients with abnormalities in peripheral vs. central mechanisms of cardiovascular stress responses.

 

Source: Peckerman A, LaManca JJ, Qureishi B, Dahl KA, Golfetti R, Yamamoto Y, Natelson BH. Baroreceptor reflex and integrative stress responses in chronic fatigue syndrome. Psychosom Med. 2003 Sep-Oct;65(5):889-95. http://www.ncbi.nlm.nih.gov/pubmed/14508037

 

Prolonged acetylcholine-induced vasodilatation in the peripheral microcirculation of patients with chronic fatigue syndrome

Abstract:

Although the aetiology of chronic fatigue syndrome (CFS) is unknown, there have been a number of reports of blood flow abnormalities within the cerebral circulation and systemic blood pressure defects manifesting as orthostatic intolerance. Neither of these phenomena has been explained adequately, but recent reports have linked cerebral hypoperfusion to abnormalities in cholinergic metabolism.

Our group has previously reported enhanced skin vasodilatation in response to cumulative doses of transdermally applied acetylcholine (ACh), implying an alteration of peripheral cholinergic function. To investigate this further, we studied the time course of ACh-induced vasodilatation following a single dose of ACh in 30 patients with CFS and 30 age- and gender-matched healthy control subjects.

No differences in peak blood flow was seen between patients and controls, but the time taken for the ACh response to recover to baseline was significantly longer in the CFS patients than in control subjects. The time taken to decay to 75% of the peak response in patients and controls was 13.7 +/- 11.3 versus 8.9 +/- 3.7 min (P = 0.03), respectively, and time taken to decay to 50% of the peak response was 24.5 +/- 18.8 versus 15.1 +/- 8.9 min (P = 0.03), respectively.

Prolongation of ACh-induced vasodilatation is suggestive of a disturbance to cholinergic pathways, perhaps within the vascular endothelium of patients with CFS, and might be related to some of the unusual vascular symptoms, such as hypotension and orthostatic intolerance, which are characteristic of the condition.

 

Source: Khan F, Spence V, Kennedy G, Belch JJ. Prolonged acetylcholine-induced vasodilatation in the peripheral microcirculation of patients with chronic fatigue syndrome. Clin Physiol Funct Imaging. 2003 Sep;23(5):282-5. http://www.ncbi.nlm.nih.gov/pubmed/12950326

Hemodynamic and neurohumoral responses to head-up tilt in patients with chronic fatigue syndrome

Abstract:

BACKGROUND: Data on the prevalence of orthostatic intolerance (OI) in patients with chronic fatigue syndrome (CFS) are limited and controversial. We tested the hypothesis that a majority of CFS patients exhibit OI during head-up tilt.

METHODS: Hemodynamic and neurohumoral responses to 40 minutes of head-up tilt were studied in 36 CFS patients and 36 healthy controls. Changes in stroke volume, cardiac output and peripheral vascular resistance were estimated from finger arterial pressure waveform analysis (Modelflow). Blood samples were drawn before and at the end of head-up tilt for measurement of plasma catecholamines.

RESULTS: At baseline, supine heart rate was higher in CFS patients (CFS: 66.4 +/- 8.4 bpm; controls: 57.4 +/- 6.6 bpm; p < 0.001) as was the plasma epinephrine level (CFS: 0.11 +/- 0.07 nmol/l; controls: 0.08 +/- 0.07 nmol/l: p = 0.015). An abnormal blood pressure and/or heart rate response to head-up tilt was seen in 10 (27.8 %) CFS patients (6 presyncope, 2 postural tachycardia, 2 tachycardia and presyncope) and 6 (16.7 %, p = 0.26) controls (5 presyncope, 1 tachycardia, 2 tachycardia and presyncope). Head-up tilt-negative CFS patients showed a larger decrease in stroke volume during tilt (-46.9 +/- 10.6) than head-up tilt-negative controls (-40.3 +/- 13.6 %, p = 0.008). Plasma catecholamine responses to head-up tilt did not differ between these groups.

CONCLUSION: Head-up tilt evokes postural tachycardia or (pre)syncope in a minority of CFS patients. The observations in head-up tilt-negative CFS patients of a higher heart rate at baseline together with a marked decrease in stroke volume in response to head-up tilt may point to deconditioning.

 

Source: Timmers HJ, Wieling W, Soetekouw PM, Bleijenberg G, Van Der Meer JW, Lenders JW. Hemodynamic and neurohumoral responses to head-up tilt in patients with chronic fatigue syndrome. Clin Auton Res. 2002 Aug;12(4):273-80. http://www.ncbi.nlm.nih.gov/pubmed/12357281

 

Impaired postural cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance

Abstract:

OBJECTIVES: To measure postural changes in cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance.

STUDY DESIGN: We studied 28 patients (age, 10 to 22 years) and 20 healthy control subjects (age, 6 to 27 years). Cerebral oxygenated hemoglobin (oxy-Hb) and deoxygenated Hb were noninvasively and continuously measured with near infrared spectroscopy during active standing. Beat-to-beat arterial pressure was monitored by Finapres.

RESULTS: Orthostatic intolerance determined by cardiovascular responses to standing was observed in 16 of 28 patients: instantaneous orthostatic hypotension in 8, delayed orthostatic hypotension in 2, and postural orthostatic tachycardia in 6. A rapid recovery of oxy-Hb by near infrared spectroscopy at the onset of active standing was not found in 15 of 16 patients with chronic fatigue and orthostatic intolerance and in 6 of 12 patients with chronic fatigue without orthostatic intolerance but only in 2 of 20 control subjects. Thirteen of 16 patients with orthostatic intolerance showed prolonged reduction in oxy-Hb during standing.

CONCLUSIONS: Impaired cerebral hemodynamics in patients with chronic fatigue syndrome and postural orthostatic tachycardia suggest a link between impaired cerebral oxygenation and chronic fatigue. However, this cannot explain the symptoms in patients meeting the criteria of chronic fatigue without orthostatic intolerance.

Comment in:

Chronic fatigue syndrome and Addison’s disease. [J Pediatr. 2003]

Orthostatic intolerance and chronic fatigue syndrome: new light on an old problem. [J Pediatr. 2002]

 

Source: Tanaka H, Matsushima R, Tamai H, Kajimoto Y. Impaired postural cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance. J Pediatr. 2002 Apr;140(4):412-7. http://www.ncbi.nlm.nih.gov/pubmed/12006954

 

Autonomic nervous system dysfunction in adolescents with postural orthostatic tachycardia syndrome and chronic fatigue syndrome is characterized by attenuated vagal baroreflex and potentiated sympathetic vasomotion

Abstract:

The objective was to determine the nature of autonomic and vasomotor changes in adolescent patients with orthostatic tachycardia associated with the chronic fatigue syndrome (CFS) and the postural orthostatic tachycardia syndrome (POTS).

Continuous electrocardiography and arterial tonometry was used to investigate the heart rate and blood pressure responses before and 3-5 min after head-up tilt in 22 adolescents with POTS and 14 adolescents with CFS, compared with control subjects comprising 10 healthy adolescents and 20 patients with simple faint. Heart rate and blood pressure variability, determined baroreceptor function using transfer function analysis, and measured cardiac vagal and adrenergic autonomic responses were calculated using timed breathing and the quantitative Valsalva maneuver.

Two of 10 healthy controls and 14 of 20 simple faint patients experienced vasovagal syncope during head-up tilt. By design, all CFS and POTS patients experienced orthostatic tachycardia, often associated with hypotension. R-R interval and heart rate variability were decreased in CFS and POTS patients compared with control subjects and remained decreased with head-up tilt. Low-frequency (0.05-0.15 Hz) blood pressure variability reflecting vasomotion was increased in CFS and POTS patients compared with control subjects and increased further with head-up tilt. This was associated with depressed baroreflex transfer indicating baroreceptor attenuation through defective vagal efferent response. Only the sympathetic response remained. Heart rate variability declined progressively from normal healthy control subjects through syncope to POTS to CFS patients. Timed breathing and Valsalva maneuver were most often normal in CFS and POTS patients, although abnormalities in select individuals were found.

Heart rate and blood pressure regulation in POTS and CFS patients are similar and indicate attenuated efferent vagal baroreflex associated with increased vasomotor tone. Loss of beat-to-beat heart rate control may contribute to a destabilized blood pressure resulting in orthostatic intolerance. The dysautonomia of orthostatic intolerance in POTS and in chronic fatigue are similar.

 

Source: Stewart JM. Autonomic nervous system dysfunction in adolescents with postural orthostatic tachycardia syndrome and chronic fatigue syndrome is characterized by attenuated vagal baroreflex and potentiated sympathetic vasomotion. Pediatr Res. 2000 Aug;48(2):218-26. http://www.ncbi.nlm.nih.gov/pubmed/10926298

 

The roles of orthostatic hypotension, orthostatic tachycardia, and subnormal erythrocyte volume in the pathogenesis of the chronic fatigue syndrome

Abstract:

BACKGROUND: Orthostatic hypotension during upright tilt is an important physical disorder in patients with chronic fatigue syndrome. We have tested its occurrence during prolonged standing, whether it is correctable, and whether reduced circulating erythrocyte volume is present.

METHODS: Fifteen patients were randomly selected from a large population of patients with chronic fatigue syndrome, studied, and observed for several years (by DSB). Blood pressure (BP) and heart rate (HR) measured with Dinamap every minute for 30 minutes supine and 60 minutes standing were compared with these findings in 15 healthy age- and gender-matched control subjects and later during lower body compression with military antishock trousers (MAST). Plasma catecholamines and circulating erythrocyte and plasma volumes were also measured by isotopic dilution methods.

RESULTS: Abnormal findings in the patients included excessive orthostatic reductions in systolic (P < 0.001) and diastolic BP (P < 0.001) and excessive orthostatic tachycardia (P < 0.01), together with presyncopal symptoms in 11 of the 15 patients and in none of the control subjects after standing for 60 min. Lower body compression with the MAST restored all orthostatic measurements to normal and overcame presyncopal symptoms within 10 min. Circulating erythrocyte but not plasma volumes were subnormal in the 12 women (P < 0.01) and plasma norepinephrine concentration rose excessively after standing for 10 min.

CONCLUSION: Delayed orthostatic hypotension and/or tachycardia caused by excessive gravitational venous pooling, which is correctable with external lower-body compression, together with subnormal circulating erythrocyte volume, are very frequent, although not invariably demonstrable, findings in moderate to severe chronic fatigue syndrome. When present, they may be involved in its pathogenesis.

 

Source: Streeten DH, Thomas D, Bell DS. The roles of orthostatic hypotension, orthostatic tachycardia, and subnormal erythrocyte volume in the pathogenesis of the chronic fatigue syndrome. Am J Med Sci. 2000 Jul;320(1):1-8. http://www.ncbi.nlm.nih.gov/pubmed/10910366

 

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

 

Orthostatic intolerance and chronic fatigue syndrome associated with Ehlers-Danlos syndrome

Abstract:

OBJECTIVE: To report chronic fatigue syndrome (CFS) associated with both Ehlers-Danlos syndrome (EDS) and orthostatic intolerance.

STUDY DESIGN: Case series of adolescents referred to a tertiary clinic for the evaluation of CFS. All subjects had 2-dimensional echocardiography, tests of orthostatic tolerance, and examinations by both a geneticist and an ophthalmologist.

RESULTS: Twelve patients (11 female), median age 15.5 years, met diagnostic criteria for CFS and EDS, and all had either postural tachycardia or neurally mediated hypotension in response to orthostatic stress. Six had classical-type EDS and 6 had hypermobile-type EDS.

CONCLUSIONS: Among patients with CFS and orthostatic intolerance, a subset also has EDS. We propose that the occurrence of these syndromes together can be attributed to the abnormal connective tissue in dependent blood vessels of those with EDS, which permits veins to distend excessively in response to ordinary hydrostatic pressures. This in turn leads to increased venous pooling and its hemodynamic and symptomatic consequences. These observations suggest that a careful search for hypermobility and connective tissue abnormalities should be part of the evaluation of patients with CFS and orthostatic intolerance syndromes.

 

Source: Rowe PC, Barron DF, Calkins H, Maumenee IH, Tong PY, Geraghty MT. Orthostatic intolerance and chronic fatigue syndrome associated with Ehlers-Danlos syndrome. J Pediatr. 1999 Oct;135(4):494-9. http://www.ncbi.nlm.nih.gov/pubmed/10518084