Tag: tilt-table test

Cardiovascular response during head-up tilt in chronic fatigue syndrome

Abstract:

This study examined the cardiovascular response to orthostatic challenge, and incidence and mechanisms of neurally mediated hypotension in chronic fatigue syndrome (CFS) during a head-up tilt test. Stroke volume was obtained by a thoracic impedance cardiograph, and continuous heart rate and blood pressure were recorded during a 45-min 70 degrees head-up tilt test.

Thirty-nine CFS patients and 31 healthy physically inactive control subjects were studied. A positive tilt, i.e. a drop in systolic blood pressure of > 25 mmHg, no concurrent increase in heart rate and/or development of presyncopal symptoms, was seen in 11 CFS patients and 12 control subjects (P > 0.05). During baseline and the first 5 min of head-up tilt, CFS patients had higher heart rate and smaller pulsatile-systolic area than control subjects (P < 0.05). Among subjects who completed the test, those with CFS had higher heart rate and smaller stroke volume (P < 0.05) than corresponding control subjects.

When comparing those who had a positive test outcome in each group, CFS patients had higher heart rates and lower pulse pressure and pulsatile-systolic areas during the last 4 min before being returned to supine (P < 0.05).

These data show that there are baseline differences in the cardiovascular profiles of CFS patients when compared with control subjects and that this profile is maintained during head-up tilt. However, the frequency of positive tilts and the haemodynamic adjustments made to this orthostatic challenge are not different between groups.

 

Source: LaManca JJ, Peckerman A, Walker J, Kesil W, Cook S, Taylor A, Natelson BH. Cardiovascular response during head-up tilt in chronic fatigue syndrome. Clin Physiol. 1999 Mar;19(2):111-20. http://www.ncbi.nlm.nih.gov/pubmed/10200892

 

Orthostatic intolerance in the chronic fatigue syndrome

Abstract:

This study aims to investigate the prevalence and pathophysiology of orthostatic intolerance (OI) and its potential contribution to symptoms of a group of unselected patients with chronic fatigue syndrome (CFS).

Seventy five patients (65 women, 10 men) with CFS were evaluated. During an initial visit, a clinical suspicion as to the likelihood of observing laboratory evidence of OI was assigned. Laboratory investigation consisted of beat-to-beat recordings of heart rate, blood pressure (Finapres), and stroke volume (impedance cardiograph) while supine and during 80 degrees head-up tilt (HUT), during rhythmic deep breathing (6 breaths/min) and during the Valsalva maneuver. The responses of 48 age-matched healthy controls who had no history of OI were used to define the range of normal responses to these three maneuvers.

Forty percent of patients with CFS had OI during head-up tilt. Sixteen exhibited neurally-mediated syncope alone, seven tachycardia (> 35 bpm averaged over the whole of the head-up tilt) and six a mixture of tachycardia and syncope. Eight of 48 controls exhibited neurally-mediated syncope. The responses to the Valsalva maneuver and to deep breathing were similar in controls and patients. On average, the duration of disease and patient age were significantly less and the onset of symptoms was more often subacute in patients with OI than in those without OI.

We conclude that there exists a clinically identifiable subgroup of patients with CFS and OI that differs from control subjects and from those with CFS without OI for whom treatment specifically aimed at improving orthostatic tolerance may be indicated.

 

Source: Schondorf R, Benoit J, Wein T, Phaneuf D. Orthostatic intolerance in the chronic fatigue syndrome. J Auton Nerv Syst. 1999 Feb 15;75(2-3):192-201. http://www.ncbi.nlm.nih.gov/pubmed/10189122

 

Neurally mediated hypotension and autonomic dysfunction measured by heart rate variability during head-up tilt testing in children with chronic fatigue syndrome

Abstract:

Recent investigations suggest a role for neurally mediated hypotension (NMH) in the symptomatology of chronic fatigue syndrome (CFS) in adults. Our previous observations in children with NMH and syncope (S) unrelated to CFS indicate that the modulation of sympathetic and parasympathetic tone measured by indices of heart rate variability (HRV) is abnormal in children who faint during head-up tilt (HUT). In order to determine the effects of autonomic tone on HUT in children with CFS we performed measurements of HRV during HUT in 16 patients aged 11-19 with CFS.

Data were compared to 26 patients evaluated for syncope and with 13 normal control subjects. After 30 minutes supine, patients were tilted to 80 degrees for 40 minutes or until syncope occurred. Time domain indices included RR interval, SDNN, RMSSD, and pNN50. An autoregressive model was used to calculate power spectra. LFP (.04-.15 Hz), HFP (.15-.40Hz), and TP (.01-.40Hz). Data were obtained supine (baseline) and after HUT.

Thirteen CFS patients fainted (CFS+, 5/13 pure vasodepressor syncope) and three patients did not (CFS-). Sixteen syncope patients fainted (S+, all mixed vasodepressor-cardioinhibitory) and 10 did not (S-). Four control patients fainted (Control+, all mixed vasodepressor-cardioinhibitory) and nine did not (Control-). Baseline indices of HRV were not different between Control+ and S+, and between Control- and S-, but were depressed in S+ compared to S-. HRV indices were strikingly decreased in CFS patients compared to all other groups.

With tilt, SDNN, RMSSD, and pNN50 and spectral indices decreased in all groups, remaining much depressed in CFS compared to S or control subjects. With HUT, sympathovagal indices (LFP/HFP, nLFP, and nHFP) were relatively unchanged in CFS, which contrasts with the increase in nLFP with HUT in all other groups. With syncope RMSSD, SDNN, LFP, TP, and HFP increased in S+ (and Control+), suggesting enhanced vagal heart rate regulation. These increases were not observed in CFS+ patients.

CFS is associated with NMH during HUT in children. All indices of HRV are markedly depressed in CFS patients, even when compared with already low HRV in S+ or Control+ patients. Sympathovagal balance does not shift toward enhanced sympathetic modulation of heart rate with HUT and there is blunting in the overall HRV response with syncope during HUT. Taken together these data may indicate autonomic impairment in patients with CFS.

 

Source: Stewart J, Weldon A, Arlievsky N, Li K, Munoz J. Neurally mediated hypotension and autonomic dysfunction measured by heart rate variability during head-up tilt testing in children with chronic fatigue syndrome. Clin Auton Res. 1998 Aug;8(4):221-30. http://www.ncbi.nlm.nih.gov/pubmed/9791743

 

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

 

The role of delayed orthostatic hypotension in the pathogenesis of chronic fatigue

Abstract:

Past studies have shown that severe fatigue was the presenting symptom in six of seven patients with delayed orthostatic hypotension and that tilt table-induced hypotension was found in 22 of 23 patients with the chronic fatigue syndrome. We have determined the prevalence of fatigue, volunteered in response to a nonspecific pre-examination questionnaire used in 431 patients, each subsequently diagnosed as having one of eight neurological or endocrine disorders.

The results show that fatigue is a very common symptom in patients with delayed orthostatic hypotension (n = 21), as well as both primary (n = 30) and secondary (n = 106) hypocortisolism: 70-83% in all groups. In contrast, fatigue was an uncommon complaint in patients with multiple system atrophy (MSA) (n = 30), pituitary disorders without hypocortisolism (n = 106) or idiopathic hirsutism (n = 96): 7-33% in all groups, and was intermediate in prevalence in patients with acute hyperadrenergic orthostatic hypotension (n = 32): 41%.

It is concluded that fatigue commonly results from delayed orthostatic hypotension and all forms of hypocortisolism but is less common in patients with acute orthostatic hypotension, both idiopathic and due to MSA, which more commonly present with lightheadedness or syncope.

 

Source: Streeten DH, Anderson GH Jr. The role of delayed orthostatic hypotension in the pathogenesis of chronic fatigue. Clin Auton Res. 1998 Apr;8(2):119-24. http://www.ncbi.nlm.nih.gov/pubmed/9613802

 

Comparison of heart rate variability in patients with chronic fatigue syndrome and controls

Abstract:

Recent studies have reported a close association between chronic fatigue syndrome and neurally mediated hypotension. We hypothesized that this association may result from an abnormality in autonomic function among patients with chronic fatigue syndrome, which may be detectable using an analysis of heart rate variability.

We prospectively studied 19 patients who fulfilled the Centers for Disease Control criteria for chronic fatigue syndrome and 11 controls. Each subject underwent a two-stage tilt-table test while wearing a Holter monitor. Heart rate variability was assessed in the supine baseline position and during upright tilt using frequency domain parameters.

In the baseline supine position, high frequency (HF) power, low frequency (LF) power, and the ratio of low frequency power to high frequency power (LF/HF ratio) were similar. In both patient groups, upright tilt resulted in a similar decrease in HF power, increase in LF power, and increase in the LH/HF ratio.

In conclusion, autonomic function, as assessed using an analysis of heart rate variability, does not differ in the baseline supine state, nor in response to upright tilt among patients with chronic fatigue syndrome and healthy controls.

 

Source: Yataco A, Talo H, Rowe P, Kass DA, Berger RD, Calkins H. Comparison of heart rate variability in patients with chronic fatigue syndrome and controls. Clin Auton Res. 1997 Dec;7(6):293-7. http://www.ncbi.nlm.nih.gov/pubmed/9430800

 

Pathogenesis and management of delayed orthostatic hypotension in patients with chronic fatigue syndrome

Abstract:

The relationship between orthostatic hypotension and chronic fatigue syndrome (CFS) has been reported previously. To study the pathogenesis and management of delayed orthostatic hypotension in patients with CFS, a case comparison study with follow-up of 8 weeks has been designed.

A group of 78 patients with CFS (mean age 40 years; 49% men and 51% women), who fulfilled the Centre for Disease Control and Prevention criteria were studied. There were 38 healthy controls (mean age 43 years; 47% men and 53% women).

At entry to the study each subject underwent an upright tilt-table test, and clinical and laboratory evaluation. Patients with orthostatic hypotension were offered therapy with sodium chloride (1200 mg) in a sustained-release formulation for 3 weeks, prior to resubmission to the tilt-table testing, and clinical and laboratory evaluation.

An abnormal response to upright tilt was observed in 22 of 78 patients with CFS. After sodium chloride therapy for 8 weeks, tilt-table testing was repeated on the 22 patients with an abnormal response at baseline. Of these 22 patients, 10 redeveloped orthostatic hypotension, while 11 did not show an abnormal response to the test and reported an improvement of CFS symptoms.

However, those CFS patients who again developed an abnormal response to tilt-test had a significantly reduced plasma renin activity (0.79 pmol/ml per h) compared both with healthy controls (1.29 pmol/ml per h) and with those 11 chronic fatigue patients (1.0 pmol/ml per h) who improved after sodium chloride therapy (p = 0.04).

In conclusion, in our study CFS patients who did not respond to sodium chloride therapy were found to have low plasma renin activity. In these patients an abnormal renin-angiotensin-aldosterone system could explain the pathogenesis of orthostatic hypotension and the abnormal response to treatment.

 

Source: De Lorenzo F, Hargreaves J, Kakkar VV. Pathogenesis and management of delayed orthostatic hypotension in patients with chronic fatigue syndrome. Clin Auton Res. 1997 Aug;7(4):185-90. http://www.ncbi.nlm.nih.gov/pubmed/9292244

 

Does the chronic fatigue syndrome involve the autonomic nervous system?

Abstract:

PURPOSE: To investigate the role of the autonomic nervous system in the symptoms of patients with chronic fatigue syndrome (CFS) and delineate the pathogenesis of the orthostatic Intolerance and predisposition to neurally mediated syncope reported in this patient group.

PATIENTS AND METHODS: Twenty-three CFS patients and controls performed a battery of autonomic function tests. The CFS patients completed questionnaires pertaining to autonomic and CFS symptoms, their level of physical activity, and premorbid and coexisting psychiatric disorders. The relationship between autonomic test results, cardiovascular deconditioning, and psychiatric disorders was examined with multivariate statistics and the evidence that autonomic changes seen in CFS might be secondary to a postviral, idiopathic autonomic neuropathy was explored.

RESULTS: The CFS subjects had a significant increase in baseline (P < 0.01) and maximum heart rate (HR) on standing and tilting (both P < 0.0001). Tests of parasympathetic nervous system function (the expiratory inspiratory ratio, P < 0.005; maximum minus minimum HR difference, P < 0.05), were significantly less in the CFS group as were measures of sympathetic nervous system function (systolic blood pressure decrease with tilting, P < 0.01; diastolic blood pressure decrease with tilting, P < 0.05; and the systolic blood pressure decrease during phase II of a Valsalva maneuver, P < 0.05). Twenty-five percent of CFS subjects had a positive tilt table test. The physical activity index was a significant predictor of autonomic test results (resting, sitting, standing, and tilted HR, P < 0.05 to P < 0.009); and the blood pressure decrease in phase II of the Valvalsa maneuver, P < 0.05) whereas premorbid and coexistent psychiatric conditions were not. The onset of autonomic symptoms occurred within 4 weeks of a viral infection in 46% of patients-a temporal pattern that is consistent with a postviral, idiopathic autonomic neuropathy.

CONCLUSION: Patients with CFS show alterations in measures of sympathetic and parasympathetic nervous system function. These results, which provide the physiological basis for the orthostatic intolerance and other symptoms of autonomic function in this patient group, may be explained by cardiovascular deconditioning, a postviral idiopathic autonomic neuropathy, or both.

 

Source: Freeman R, Komaroff AL. Does the chronic fatigue syndrome involve the autonomic nervous system? Am J Med. 1997 Apr;102(4):357-64. http://www.ncbi.nlm.nih.gov/pubmed/9217617

 

Possible relationship between chronic fatigue and postural tachycardia syndromes

Abstract:

Postural tachycardia syndrome refers to the development of symptoms such as light-headedness, visual blurring, palpitations and weakness on assuming an upright posture; these symptoms are relieved by resuming a supine posture. This syndrome is occasionally associated with idiopathic hypovolemia, impaired vasomotor tone, deconditioning and autonomic neuropathy, but has not been reported in association with chronic fatigue syndrome (CFS).

We describe five patients who satisfied the CFS criteria of the Centres for Disease Control and Prevention. Upright tilt-table testing induced significant hypotension and increased heart rate in all five patients, consistent with clinical and autonomic manifestation of postural tachycardia syndrome.

 

Source: De Lorenzo F, Hargreaves J, Kakkar VV. Possible relationship between chronic fatigue and postural tachycardia syndromes. Clin Auton Res. 1996 Oct;6(5):263-4. http://www.ncbi.nlm.nih.gov/pubmed/8899252

 

The relationship between neurally mediated hypotension and the chronic fatigue syndrome

Abstract:

OBJECTIVE: To compare the clinical symptoms and response evoked by upright tilt-table testing in healthy individuals and in a sample of those satisfying strict criteria for chronic fatigue syndrome.

DESIGN: Case-comparison study with mean (SD) follow-up of 24 (5) weeks.

SETTING: Tertiary care hospital.

PATIENTS AND OTHER PARTICIPANTS: A sample of 23 patients with chronic fatigue syndrome (five men and 18 women; mean age, 34 years), each of whom fulfilled the strict diagnostic criteria of the Centers for Disease Control and Prevention, was recruited from regional chronic fatigue support groups and from the investigators’ clinical practices. There were 14 healthy controls (four men and 10 women; mean age, 36 years).

INTERVENTIONS: Each subject completed a symptom questionnaire and underwent a three-stage upright tilt-table test (stage 1, 45 minutes at 70 degrees tilt; stage 2, 15 minutes at 70 degrees tilt with 1 to 2 micrograms/min of isoproterenol; and stage 3, 10 minutes at 70 degrees with 3 to 4 micrograms/min of isoproterenol). Patients were offered therapy with fludrocortisone, beta-adrenergic blocking agents, and disopyramide, alone or in combination, directed at neurally mediated hypotension.

MAIN OUTCOME MEASURES: Response to upright tilt and scores on symptom questionnaires prior to and during follow-up.

RESULTS: An abnormal response to upright tilt was observed in 22 of 23 patients with chronic fatigue syndrome vs four of 14 controls (P < .001). Seventy percent of chronic fatigue syndrome patients, but no controls, had an abnormal response during stage 1 (P < .001). Nine patients reported complete or nearly complete resolution of chronic fatigue syndrome symptoms after therapy directed at neurally mediated hypotension.

CONCLUSIONS: We conclude that chronic fatigue syndrome is associated with neurally mediated hypotension and that its symptoms may be improved in a subset of patients by therapy directed at this abnormal cardiovascular reflex.

Comment in:

Chronic fatigue syndrome and neurally mediated hypotension. [JAMA. 1996]

Orthostatic hypotension and chronic fatigue syndrome. [JAMA. 2001]

Chronic fatigue syndrome and neurally mediated hypotension. [JAMA. 1996]

Chronic fatigue syndrome and neurally mediated hypotension. [JAMA. 1996]

 

Source: Bou-Holaigah I, Rowe PC, Kan J, Calkins H. The relationship between neurally mediated hypotension and the chronic fatigue syndrome. JAMA. 1995 Sep 27;274(12):961-7. http://www.ncbi.nlm.nih.gov/pubmed/7674527