Tag: heart rate

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

 

Fractal analysis and recurrence quantification analysis of heart rate and pulse transit time for diagnosing chronic fatigue syndrome

Abstract:

This study aimed to develop a method to distinguish between the cardiovascular reactivity in chronic fatigue syndrome (CFS) and other patient populations.

Patients with CFS (n = 23), familial Mediterranean fever (n = 15), psoriatic arthritis (n = 10), generalized anxiety disorder (n = 12), neurally mediated syncope (n = 20), and healthy subjects (n = 20) were evaluated with a shortened head-up tilt test (HUTT). A 10-minute supine phase of the HUTT was followed by recording 600 cardiac cycles on tilt, i. e., 5 to 10 minutes. Beat-to-beat heart rate (HR) and pulse transit time (PTT) were acquisitioned. Data were processed by recurrence plot and fractal analysis. Fifty-two variables were calculated in each subject.

On multivariate analysis, the best predictors of CFS were HR-tilt-R/L, PTT-tilt-R/L, HR-supine-DET, PTT-tilt-WAVE, and HR-tilt-SD. Based on these predictors, the ‘Fractal & Recurrence Analysis-based Score’ (FRAS) was calculated: FRAS = 76.2 + 0.04*HR-supine-DET – 12.9*HR-tilt-R/L – 0.31*HR-tilt-SD – 19.27*PTT-tilt-R/L – 9.42* PTT-tilt-WAVE. The best cut-off differentiating CFS from the control population was FRAS = + 0.22. FRAS > + 0.22 was associated with CFS (sensitivity 70 % and specificity 88 %). The cardiovascular reactivity received mathematical expression with the aid of the FRAS. The shortened HUTT was well tolerated. The FRAS provides objective criteria which could become valuable in the assessment of CFS.

Comment in: Chronic fatigue syndrome and hidden happenings of the heartbeat. [Clin Auton Res. 2002]

 

Source: Naschitz JE, Sabo E, Naschitz S, Rosner I, Rozenbaum M, Priselac RM, Gaitini L, Zukerman E, Yeshurun D. Fractal analysis and recurrence quantification analysis of heart rate and pulse transit time for diagnosing chronic fatigue syndrome. Clin Auton Res. 2002 Aug;12(4):264-72. http://www.ncbi.nlm.nih.gov/pubmed/12357280

 

Hemodynamic instability in chronic fatigue syndrome: indices and diagnostic significance

Abstract:

OBJECTIVES: To evaluate the cardiovascular response to postural challenge in patients with chronic fatigue syndrome (CFS) and to determine whether the degree of instability of the cardiovascular response may aid in diagnosing CFS.

METHODS: Patients with CFS (n = 25) and their age- and gender-matched healthy controls (n = 37), patients with fibromyalgia (n = 30), generalized anxiety disorder (n = 15), and essential hypertension (n = 20) were evaluated with the aid of a standardized tilt test. The blood pressure (BP) and heart rate (HR) were recorded during 10 minutes of recumbence and 30 minutes of head-up tilt. We designated BP changes as the differences between successive BP values and the last recumbent BP. The average and standard deviation (SD) were calculated. Time curves of BP differences were loaded into a computerized image analyzer, and their outline ratios and fractal dimensions were measured. HR changes were determined similarly. The average and SD of the parameters were calculated, and intergroup comparisons were performed.

RESULTS: On multivariate analysis, the independent predictors of CFS patients versus healthy controls were the fractal dimension of absolute values of the systolic BP changes (SYST-FD.abs), the standard deviation of the current values of the systolic BP changes (SYST-SD.cur), and the standard deviation of the current values of the heart rate changes (HR-SD.cur). The following equation was deduced to calculate the hemodynamic instability score (HIS) in the individual patient: HIS = 64.3303 + (SYST-FD.abs x -68.0135) + (SYST-SD.cur x 111.3726) + (HR-SD.cur x 60.4164). The best cutoff differentiating CFS from the healthy controls was -0.98. HIS values >-0.98 were associated with CFS (sensitivity 97%, specificity 97%). The HIS differed significantly between CFS and other groups (P <.0001) except for generalized anxiety disorder. Group averages (SD) of HIS were CFS = +3.72 (5.02), healthy = -4.62 (2.26), fibromyalgia = -3.27 (2.63), hypertension = -5.53 (2.24), and generalized anxiety disorder = +1.08 (5.2).

CONCLUSION: The HIS adds objective criteria confirming the diagnosis of CFS.

Copyright 2001 by W.B. Saunders Company

 

Source: Naschitz JE, Sabo E, Naschitz S, Shaviv N, Rosner I, Rozenbaum M, Gaitini L, Ahdoot A, Ahdoot M, Priselac RM, Eldar S, Zukerman E, Yeshurun D. Hemodynamic instability in chronic fatigue syndrome: indices and diagnostic significance. Semin Arthritis Rheum. 2001 Dec;31(3):199-208. http://www.ncbi.nlm.nih.gov/pubmed/11740800

 

Cardiovascular responses of women with chronic fatigue syndrome to stressful cognitive testing before and after strenuous exercise

Abstract:

OBJECTIVE: The purpose of this study was to compare the cardiovascular responses of patients with chronic fatigue syndrome (CFS) to healthy control subjects when performing stressful cognitive tasks before and after strenuous exercise.

METHOD: Beat-by-beat blood pressure and electrocardiogram were recorded on 19 women with CFS and 20 healthy nonexercising (ie, sedentary) women while they performed cognitive tests before, immediately after, and 24 hours after incremental exercise to exhaustion.

RESULTS: Diminished heart rate (p <.01) and systolic (p <.01) and diastolic (p <.01) blood pressure responses to stressful cognitive testing were seen in patients with CFS when compared with healthy, sedentary controls. This diminished stress response was seen consistently in patients with CFS across three separate cognitive testing sessions. Also, significant negative correlations between self-ratings of CFS symptom severity and cardiovascular responses were seen (r = -0.62, p <.01).

CONCLUSIONS: Women with CFS have a diminished cardiovascular response to cognitive stress; however, exercise did not magnify this effect. Also, the data showed that the patients with the lowest cardiovascular reactivity had the highest ratings of CFS symptom severity, which suggests that the individual response of the patient with CFS to stress plays a role in the common complaint of symptoms worsening after stress.

 

Source: LaManca JJ, Peckerman A, Sisto SA, DeLuca J, Cook S, Natelson BH. Cardiovascular responses of women with chronic fatigue syndrome to stressful cognitive testing before and after strenuous exercise. Psychosom Med. 2001 Sep-Oct;63(5):756-64. http://www.ncbi.nlm.nih.gov/pubmed/11573024

 

Physiological responses to incremental exercise in patients with chronic fatigue syndrome

Abstract:

PURPOSE: The purpose of this investigation was to characterize the physiological response profiles of patients with chronic fatigue syndrome (CFS), to an incremental exercise test, performed to the limit of tolerance.

METHODS: Fifteen patients (12 women and three men) who fulfilled the case definition for chronic fatigue syndrome, and 15 healthy, sedentary, age- and sex-matched controls, performed an incremental progressive all-out treadmill test (cardiopulmonary exercise test).

RESULTS: As a group, the CFS patients demonstrated significantly lower cardiovascular as well as ventilatory values at peak exercise, compared with the control group. At similar relative submaximal exercise levels (% peak VO(2)), the CFS patients portrayed response patterns (trending phenomenon) characterized, in most parameters, by similar intercepts, but either lower (VCO(2), HR, O(2pulse), V(E), V(T), PETCO(2)) or higher (B(f), V(E)/VCO(2)) trending kinetics in the CFS compared with the control group. It was found that the primary exercise-related physiological difference between the CFS and the control group was their significantly lower heart rate at any equal relative and at maximal work level. Assuming maximal effort by all (indicated by RER, PETCO(2), and subjective exhaustion), these results could indicate either cardiac or peripheral insufficiency embedded in the pathology of CFS patients.

CONCLUSION: We conclude that indexes from cardiopulmonary exercise testing may be used as objective discriminatory indicators for evaluation of patients complaining of chronic fatigue syndrome.

 

Source: Inbar O, Dlin R, Rotstein A, Whipp BJ. Physiological responses to incremental exercise in patients with chronic fatigue syndrome. Med Sci Sports Exerc. 2001 Sep;33(9):1463-70. http://www.ncbi.nlm.nih.gov/pubmed/11528333

 

Cardiovascular response to upright tilt in fibromyalgia differs from that in chronic fatigue syndrome

Abstract:

OBJECTIVE: To compare the cardiovascular response during postural challenge of patients with fibromyalgia (FM) to those with chronic fatigue syndrome (CFS).

METHODS: Age and sex matched patients were studied, 38 with FM, 30 with CFS, and 37 healthy subjects. Blood pressure (BP) and heart rate (HR) were recorded during 10 min of recumbence and 30 min of head-up tilt. Differences between successive BP values and the last recumbent BP, their average, and standard deviation (SD) were calculated. Time curves of BP differences were analyzed by computer and their outline ratios (OR) and fractal dimensions (FD) were measured. HR differences were determined similarly. Based on the latter measurements, each subject’s discriminant score (DS) was computed.

RESULTS: For patients and controls average DS values were: FM: -3.68 (SD 2.7), CFS: 3.72 (SD 5.02), and healthy controls: -4.62 (SD 2.24). DS values differed significantly between FM and CFS (p < 0.0001). Subgroups of FM patients with and without fatigue had comparable DS values.

CONCLUSION: The DS confers numerical expression to the cardiovascular response during postural challenge. DS values in FM were significantly different from DS in CFS, suggesting that homeostatic responses in FM and CFS are dissimilar. This observation challenges the hypothesis that FM and CFS share a common derangement of the stress-response system.

 

Source: Naschitz JE, Rozenbaum M, Rosner I, Sabo E, Priselac RM, Shaviv N, Ahdoot A, Ahdoot M, Gaitini L, Eldar S, Yeshurun D. Cardiovascular response to upright tilt in fibromyalgia differs from that in chronic fatigue syndrome. J Rheumatol. 2001 Jun;28(6):1356-60. http://www.ncbi.nlm.nih.gov/pubmed/11409131

 

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

 

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

 

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

 

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