1
|
Snapper H, Cheshire WP. Oral and intravenous hydration in the treatment of orthostatic hypotension and postural tachycardia syndrome. Auton Neurosci 2022; 238:102951. [PMID: 35123367 DOI: 10.1016/j.autneu.2022.102951] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 12/07/2021] [Accepted: 01/25/2022] [Indexed: 01/21/2023]
Abstract
Hydration with water and salt is the mainstay of treatment for autonomic nervous system disorders that impair orthostatic tolerance. The goal is to expand intravascular volume to compensate for the downward displacement of blood volume that occurs when standing and thereby sustain cerebral perfusion and restore quality of life. Despite strong consensus recommendations for salt supplementation as standard treatment of these disorders, published evidence of benefit is relatively weak, and no randomized clinical trials have occurred. This review summarizes the physiological rationale for hydration and evaluates the literature on oral and intravenous hydration in the treatment of neurogenic orthostatic hypotension, postural tachycardia syndrome, and recurrent vasovagal syncope. We conclude that oral salt replacement is indicated for treatment of neurogenic orthostatic hypotension because these patients have excessive renal sodium excretion, and for treatment of chronic orthostatic intolerance because these patients are often hypovolemic. As not all patients are able to tolerate sufficient oral hydration, there is also a role for intravenous volume-loading in severe cases of postural tachycardia syndrome. We offer guidance, based on review of the literature and the clinical judgment of a cardiologist and neurologist with experience treating autonomic disorders, regarding the option of ongoing intravenous hydration for treatment of severe, refractory cases of postural tachycardia syndrome.
Collapse
Affiliation(s)
- Howard Snapper
- Department of Cardiology, Wellstar Healthcare System, Marietta, GA 30060, USA.
| | - William P Cheshire
- Division of Autonomic Disorders, Department of Neurology, Mayo Clinic, Jacksonville, FL 32224, USA
| |
Collapse
|
2
|
Loughlin EA, Judge CS, Gorey SE, Costello MM, Murphy RP, Waters RF, Hughes DS, Kenny RA, O'Donnell MJ, Canavan MD. Increased Salt Intake for Orthostatic Intolerance Syndromes: A Systematic Review and Meta-Analysis. Am J Med 2020; 133:1471-1478.e4. [PMID: 32603788 DOI: 10.1016/j.amjmed.2020.05.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/04/2020] [Accepted: 05/04/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Guidelines recommend increased salt intake as a first-line recommendation in the management of symptomatic orthostatic hypotension and recurrent syncope. There have been no systematic reviews of this intervention. We sought to summarize the evidence for increased salt intake in patients with orthostatic intolerance syndromes. METHODS We conducted a systematic review and meta-analysis of studies in PubMed, EMBASE, and CINAHL. Interventional studies that increased salt intake in individuals with orthostatic intolerance syndromes were included. Primary outcome measures included incidence of falls and injuries, and rates of syncope and presyncope. Secondary outcome measures included other orthostatic intolerance symptoms, blood pressure, and heart rate. RESULTS A total of 14 studies were eligible, including participants with orthostatic hypotension, syncope, postural orthostatic tachycardia syndrome, and idiopathic orthostatic tachycardia (n = 391). Mean age was 35.6 (± 15) years. All studies were small and short-term (<60 mins-90 days). No study reported on the effect of increased salt intake on falls or injuries. Meta-analysis demonstrated that during head-up tilt, mean time to presyncope with salt intake increased by 1.57 minutes (95% confidence interval [CI], 1.26-1.88), mean systolic blood pressure increased by 12.27 mm Hg (95% CI, 10.86-13.68), and mean heart rate decreased by -3.97 beats per minute (95% CI, -4.08 to -3.86), compared with control. Increased salt increased supine blood pressure by 1.03 mm Hg (95% CI, 0.81 to 1.25). Increased salt intake resulted in an improvement or resolution of symptoms in 62.3% (95% CI, 51.6 to 72.6) of participants in short-term follow-up studies (mean follow-up of 44.3 days, 6 studies; n=91). Methodological quality of studies were low with high statistical heterogeneity in all meta-analyses. CONCLUSIONS Our meta-analysis provides low-quality evidence of a short-term improvement in orthostatic intolerance with increased salt intake. There were no clinical trials demonstrating the efficacy and safety of increased salt intake on long-term clinical outcomes. Overall, there is a paucity of clinical trial evidence to support a cornerstone recommendation in the management of orthostatic intolerance syndromes.
Collapse
Affiliation(s)
- Elaine A Loughlin
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland.
| | - Conor S Judge
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland; Wellcome Trust - HRB, Irish Clinical Academic Training, Dublin, Ireland
| | - Sarah E Gorey
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland
| | - Maria M Costello
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland
| | - Robert P Murphy
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland
| | - Ruairi F Waters
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland
| | - Diarmaid S Hughes
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland
| | - Rose Ann Kenny
- Mercer's Institute for Successful Ageing, St. James's Hospital, Dubline, Ireland
| | - Martin J O'Donnell
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland
| | - Michelle D Canavan
- HRB-Clinical Research Facility, National University of Ireland Galway, Galway, Ireland; Galway University Hospital, Newcastle Road, Galway, Ireland
| |
Collapse
|
3
|
Sheldon R, Raj SR, Rose MS, Morillo CA, Krahn AD, Medina E, Talajic M, Kus T, Seifer CM, Lelonek M, Klingenheben T, Parkash R, Ritchie D, McRae M, Sheldon R, Rose S, Ritchie D, McCrae M, Morillo C, Malcolm V, Krahn A, Spindler B, Medina E, Talajic M, Kus T, Langlois A, Lelonek M, Raj S, Seifer C, Gardner M, Romeo M, Poirier P, Simpson C, Abdollah H, Reynolds J, Dorian P, Birnie D, Giuffre M, Gilligan D, Benditt D, Sheldon R, Raj S, Rose M, Krahn A, Morillo C, Medina E. Fludrocortisone for the Prevention of Vasovagal Syncope. J Am Coll Cardiol 2016; 68:1-9. [DOI: 10.1016/j.jacc.2016.04.030] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/31/2016] [Accepted: 04/05/2016] [Indexed: 10/21/2022]
|
4
|
Brignole M. Finally, a Drug Proves to Be Effective Against Vasovagal Syncope! J Am Coll Cardiol 2016; 68:10-2. [DOI: 10.1016/j.jacc.2016.03.595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 03/15/2016] [Indexed: 10/21/2022]
|
5
|
P-wave dispersion: an indicator of cardiac autonomic dysfunction in children with neurocardiogenic syncope. Pediatr Cardiol 2014; 35:596-600. [PMID: 24633236 DOI: 10.1007/s00246-013-0825-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Accepted: 10/03/2013] [Indexed: 10/26/2022]
Abstract
Neurocardiogenic syncope is the most frequent cause of fainting in childhood and adolescence. Although head-up tilt table testing (HUTT) was previously considered as the reference standard in the diagnosis of syncope, in children with a typical history of reflex syncope, normal physical examination, and electrocardiogram (ECG) are sufficient to cease investigation; however, according to recent reports, TT is indicated in patients in whom this diagnosis cannot be proven by initial evaluation. The hypothesis of this study is that P-wave dispersion (PWD) can be a useful electrocardiographic predictor of cardiac autonomic dysfunction in children with vasovagal syncope (VVS). The study was designed prospectively and included 50 children with positive and 50 children with negative HUTT who presented with at least two previous unexplained episodes of syncope as well as 50 sex- and age-matched healthy children as the control group. All standard 12-lead ECGs were obtained in patients and controls, and the difference between maximum and minimum durations of the P wave was defined as the PWD. A total of 100 children with VVS and 50 healthy controls were evaluated for the study. The P maximum values of HUTT-positive (HUTT[+]) patients were significantly greater than those in the HUTT-negative (HUTT[-]) and control groups(p < 0.05). In addition, mean PWD values were 50.2 ± 18.5, 39.6 ± 11.2 and 32.0 ± 11.2 ms in the HUTT(+), HUTT(-), and control groups, respectively. The difference between groups was statistically significant (p < 0.05). We suggest that PWD is an early sign of cardiac autonomic dysfunction in children with neurally mediated syncope and can be used as a noninvasive electrocardiographic test to evaluate orthostatic intolerance syndromes.
Collapse
|
6
|
Abstract
Vasovagal syncope is a common disorder that affects at least 20% of people at some time in their lives. Probably half of these patients faint recurrently; for many this causes physical trauma, a substantial reduction in quality of life, and difficulties with driving, employment and education. The last 15 years have seen striking advances in diagnostic approaches and prognostic understanding. A number of physiological, pharmacological and electrical therapies have been developed and tested to various degrees in patients. These include counterpressure manoeuvres, salt and fluid recommendations, and attempted treatment with fludrocortisone, midodrine, beta-blockers, serotonin reuptake inhibitors, and permanent pacemakers. This review highlights the most important of these advances and suggests strategies for managing this often difficult problem.
Collapse
Affiliation(s)
- Robert Sheldon
- University of Calgary, Libin Cardiovascular Institute of Alberta, Faculty of Medicine, 3330 Hospital Drive NW Calgary, Alberta, T2N 4N1, Canada.
| | | | | |
Collapse
|
7
|
|
8
|
Vlahos AP, Tzoufi M, Katsouras CS, Barka T, Sionti I, Michalis LK, Siamopoulou A, Kolettis TM. Provocation of neurocardiogenic syncope during head-up tilt testing in children: comparison between isoproterenol and nitroglycerin. Pediatrics 2007; 119:e419-25. [PMID: 17224456 DOI: 10.1542/peds.2006-1862] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Although nitroglycerin- and isoproterenol-augmented tilt tests are of equal value in the diagnosis of neurocardiogenic syncope in adults, no data exist in children. We compared the sensitivity and specificity of the 2 tests in a pediatric population. PATIENTS AND METHODS We studied 85 patients (33 boys; mean age: 11.6 +/- 2.9 years). Of them, 56 had a diagnostic history of neurocardiogenic syncope, whereas 29 served as controls. After a negative passive phase, they were randomly assigned to either intravenous isoproterenol or sublingual nitroglycerin, and tilt was continued for 20 minutes. RESULTS Sensitivity was 0.78 for the isoproterenol test and 0.79 for the nitroglycerin test, but specificity was significantly higher for isoproterenol test compared with nitroglycerin test. In patients with a positive test, the duration of the recovery period was significantly longer after nitroglycerin (8.4 +/- 2.7 minutes) than after isoproterenol (5.1 +/- 1.6 minutes). CONCLUSIONS Nitroglycerin- and isoproterenol-augmented tilt tests are associated with equal sensitivity in the diagnosis of neurocardiogenic syncope in children and adolescents. However, nitroglycerin results in more false-positive tests and produces more prolonged vasovagal symptoms. Our data do not support the routine use of nitroglycerin in the evaluation of syncope in this age group.
Collapse
Affiliation(s)
- Antonios P Vlahos
- Child Health Department, Pediatric Cardiology Division, University of Ioannina, 45110 Ioannina, Greece.
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Raj SR, Rose S, Ritchie D, Sheldon RS. The Second Prevention of Syncope Trial (POST II)--a randomized clinical trial of fludrocortisone for the prevention of neurally mediated syncope: rationale and study design. Am Heart J 2006; 151:1186.e11-7. [PMID: 16781217 DOI: 10.1016/j.ahj.2006.03.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Accepted: 03/20/2006] [Indexed: 11/25/2022]
Abstract
BACKGROUND Neurally mediated syncope is a common and frequently distressing problem. It is associated with a poor quality of life, which improves when the frequency of syncope is reduced. Few therapies for neurally mediated syncope have been proven effective. Fludrocortisone is commonly used to prevent recurrences of syncope but with little evidence to support its use. A placebo-controlled clinical trial of fludrocortisone for the prevention of neurally mediated syncope is needed. STRUCTURE OF STUDY POST II is a multicenter, international, randomized, placebo-controlled study of fludrocortisone in the prevention of neurally mediated syncope. The primary end point is the time to first recurrence of syncope. Patients will be randomized 1:1 to receive fludrocortisone 0.05 to 0.2 mg or matching placebo and followed for 1 year. Secondary end points include syncope frequency, presyncope, and quality of life. Primary analysis will be performed with an intention-to-treat approach, with a secondary on-treatment analysis. POWER CALCULATIONS Assuming a 40% risk of syncope in the control arm, a relative reduction of 40% by fludrocortisone, and a dropout rate of 20%, the enrollment of 310 patients will give an 80% power of reaching a positive conclusion about fludrocortisone therapy, with P = .05. REGISTRATION POST II is registered with both (ISRCTN 51802652) and (NCT00118482). IMPLICATIONS This study will be the first adequately powered trial to determine whether fludrocortisone is effective in preventing neurally mediated syncope. If it is effective, then fludrocortisone may become the first-line medical therapy for this condition.
Collapse
Affiliation(s)
- Satish R Raj
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University, Nashville, TN, USA
| | | | | | | |
Collapse
|
10
|
Sheldon RS, Sheldon AG, Connolly SJ, Morillo CA, Klingenheben T, Krahn AD, Koshman ML, Ritchie D. Age of first faint in patients with vasovagal syncope. J Cardiovasc Electrophysiol 2006; 17:49-54. [PMID: 16426400 DOI: 10.1111/j.1540-8167.2005.00267.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
INTRODUCTION Understanding whether vasovagal syncope is a lifelong disorder might shed insight into its physiology and affect management strategies. Accordingly, we determined the age of the first syncopal spell in adult patients who sought care for syncope. METHODS AND RESULTS Patients were 42 +/- 18 years old with 64% women. They had had a median 8 syncope spells (interquartile range [IQR]: 4, 20) with a median frequency of 1.0 syncopal spells per year. The range of syncopal spells was 1-3,375, and the range of duration of history of syncope was 0.003-70 years. The first syncopal spell occurred at ages 0-81 in a skewed distribution, with a marked mode age of 13 years, a median age of 18 years (IQR 12, 37), and a mean age of 26 +/- 20 years. The distributions were statistically indistinguishable across countries (P = 0.50), among Canadian regions (P = 0.69), and between the studies (P = 0.49). The same modal values were seen in males and females, and in patients <40 and > or =40 years old. However, patients > or =40 years had median ages of onset older than patients <40 years (36 +/- 23 vs 17 +/- 8 years). Patients had a recalled history of syncopal spells of median duration of 10 years (IQR: 2, 23), with a range of 0.003-70 years. An age of onset <44 years was 86% accurate for vasovagal syncope. CONCLUSION The most common age at which vasovagal syncope first presents is 13 years, and patients remain at risk of syncope for many years. Lifelong coping strategies may be desirable.
Collapse
Affiliation(s)
- Robert S Sheldon
- Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, Canada.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Raj SR, Koshman ML, Sheldon RS. Outcome of patients with dual-chamber pacemakers implanted for the prevention of neurally mediated syncope. Am J Cardiol 2003; 91:565-9. [PMID: 12615261 DOI: 10.1016/s0002-9149(02)03307-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Dual-chamber pacemaker insertion (PI) has been found to reduce the recurrence of neurally mediated syncope (NMS) in 3 randomized trials. However, the long-term benefits of PI are unknown. To assess the natural history of NMS, we followed a cohort of 40 patients who underwent PI for frequent NMS for 46 to 75 months. We assessed the reduction in syncope frequency after PI and the time to first recurrence of syncope. Sixty months after PI, 32.5% of patients remained free of NMS. The frequency of syncope decreased from 0.46 to 0.06 spells/month (before to after PI, p = 0.04). Two groups of patients were identified, with responders to PI defined as having a 75% decrease in the frequency of NMS. Responders (n = 22) experienced a significant decrease in the frequency of NMS (0.31 to 0.01 spells/month, p <0.0001), whereas nonresponders did not experience a similar reduction (p = 0.8). Responders could not be identified by either baseline or tilt-test parameters. Patients without an early recurrence of syncope after PI (within 6 months) experienced a significant reduction in the frequency of NMS (0.24 to 0.02 spells/month, p = 0.0002), although the reduction was not significant (p = 0.3) in patients with an early recurrence of syncope. Some, but not all, patients respond to permanent PI for NMS. The long-term benefit of permanent PI can be predicted by timing of the first recurrence of syncope, but not by preimplantation factors.
Collapse
Affiliation(s)
- Satish R Raj
- Cardiovascular Research Group, University of Calgary, Alberta, Canada
| | | | | |
Collapse
|
12
|
Schroeder C, Bush VE, Norcliffe LJ, Luft FC, Tank J, Jordan J, Hainsworth R. Water drinking acutely improves orthostatic tolerance in healthy subjects. Circulation 2002; 106:2806-11. [PMID: 12451007 DOI: 10.1161/01.cir.0000038921.64575.d0] [Citation(s) in RCA: 174] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Orthostatic symptoms and syncope are common, even in apparently healthy subjects. In patients with severe autonomic dysfunction, water drinking elicits an acute pressor response and improves orthostatic hypotension. We tested the hypothesis that water drinking also improves orthostatic tolerance in healthy subjects. METHODS AND RESULTS In a randomized, controlled, crossover fashion, 13 healthy subjects (9 men, 4 women, 31+/-2 years) ingested 500 mL and 50 mL of mineral water 15 minutes before head-up tilt on two separate days. Finger blood pressure, brachial blood pressure, heart rate, thoracic impedance, and blood flow velocity in the brachial artery and the middle cerebral artery were measured. Orthostatic tolerance was determined as the time to presyncope during a combined protocol of 20 minutes of 60 degrees head-up tilt alone, followed by additional increasing steps of lower body negative pressure (-20, -40, and -60 mm Hg for 10 minutes each or until presyncope). Drinking 500 mL of water improved orthostatic tolerance by 5+/-1 minute (range, -1 to +11 minutes, P<0.001). After drinking 500 mL of water, supine mean blood pressure increased slightly (P<0.01) as the result of increased peripheral resistance (P<0.01). It also blunted both the increase in heart rate and the decrease in stroke volume with head-up tilt. Cerebral blood flow regulation improved after water drinking. CONCLUSIONS Water drinking elicits an acute hemodynamic response and changes in cerebrovascular regulation in healthy subjects. These effects are associated with a marked improvement in orthostatic tolerance.
Collapse
Affiliation(s)
- Christoph Schroeder
- Franz-Volhard Clinical Research Center, Medical Faculty of the Charité, Humboldt-University, Berlin, Germany
| | | | | | | | | | | | | |
Collapse
|
13
|
Abstract
Syncope is a common condition that can be both disabling and expensive to treat. Although investigative modalities are sometimes required, a diagnosis can often be made with a good history and physical exam. Recent reports have identified specific historic features that are more suggestive of cardiac syncope as compared with vasovagal syncope and seizures. Advances in ambulatory electrocardiography (in particular the implantable loop recorder) have proven invaluable in both difficult-to-diagnose syncope, and in advancing our knowledge of its mechanisms. When clear dysrhythmias are manifest, appropriate therapies are self-evident. However, recurrent vasovagal syncope continues to be a condition that can be difficult to treat. Fortunately, there are well-conducted trials of both pharmacologic therapies (b-blockers, alpha agonists, and selective serotonin reuptake inhibitors) and nonpharmacologic treatments (orthostatic physical training and dual-chamber pacemakers) that should provide more guidance in the near future.
Collapse
Affiliation(s)
- Satish R Raj
- Faculty of Medicine, University of Calgary, Health Sciences Centre, 3330 Hospital Drive, NW, Calgary, Alberta, T2N 4N1, Canada.
| | | |
Collapse
|
14
|
Abstract
Patients with frequent vasovagal syncope have markedly poor quality of life and are often resistant to treatment with standard pharmacologic approaches. Vasovagal syncope is due to combinations of bradycardia and hypotension. There is accumulating evidence that many of these patients may respond to permanent cardiac pacing. Several controlled open-label studies suggest that about half of paced patients no longer faint, and most of the rest are improved. At this point, we do not know the role of placebo, and specific pacing modes in this improvement are not known. Ongoing trials will clarify how to select patients and how best to pace them.
Collapse
Affiliation(s)
- R Sheldon
- Cardiovascular Research Group, University of Calgary, Alberta, Canada.
| |
Collapse
|
15
|
Sheldon R, Sexton E, Koshman ML. Usefulness of clinical factors in predicting outcomes of passive tilt tests in patients with syncope. Am J Cardiol 2000; 85:360-4. [PMID: 11078307 DOI: 10.1016/s0002-9149(99)00747-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Pretest patient selection affects the outcome of many diagnostic tests; this may be true for tilt-table tests. We assessed the impact of patient age, sex, and symptom burden on the outcome of passive tilt tests. Two hundred one patients with idiopathic syncope (87 men, aged 45 +/- 20 years, median 5 fainting spells each) underwent passive, drug-free tilt tests for 45 minutes. Positive tests were defined as those ending in clinically reminiscent presyncope or syncope. Seventy-eight patients (39%) had a positive tilt test. Patients had a wide range of symptom burden, having a median 5 syncopal spells (interquartile range [IQR] 2.5 to 17.5) over a median 52.5 months (IQR 12 to 180) with a median frequency of 0.17 spells/month (IQR 0.042 to 0.67). None of these measures of symptom burden predicted tilt-test outcome (p = 0.33 to 0.46). In contrast, the age of the patient strongly predicted tilt-test outcome. The likelihood of a positive test was 75% in 36 patients < 25 years old and 31% in 165 patients > or = 25 years of age (p < 0.0001, chi-square for 2 x 5 table). Younger patients also fainted more quickly: patients < 25 years old fainted within 22 minutes of tilt and reached a clearly asymptotic value, whereas the likelihood of a positive tilt in patients > or = 25 years old increased linearly with time, and did not reach an asymptote. Measures of symptom burden do not predict test outcome, and younger patients are more likely to faint during passive tilt testing.
Collapse
Affiliation(s)
- R Sheldon
- Cardiovascular Research Group, University of Calgary, Alberta, Canada.
| | | | | |
Collapse
|
16
|
Burklow TR, Moak JP, Bailey JJ, Makhlouf FT. Neurally mediated cardiac syncope: autonomic modulation after normal saline infusion. J Am Coll Cardiol 1999; 33:2059-66. [PMID: 10362214 DOI: 10.1016/s0735-1097(99)00133-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES This study assessed the heart variability response to orthostatic stress during tilt table testing before and after normal saline administration. BACKGROUND The efficacy of sodium chloride and mineralocortoid in the treatment of neurally mediated cardiac syncope is attributed to intravascular volume expansion; however, their modulation of autonomic nervous system activity has not been evaluated. METHODS Heart rate variability analysis was performed on 12 adolescents with a history of syncope or presyncope (mean age 15.2+/-0.7 years) during tilt table testing. Subjects were upright 80 degrees for 30 min or until syncope. After normal saline administration, the patient was returned upright for 30 min. Heart rate variability analysis data were analyzed by an autoregression model (Burg method). RESULTS All subjects reproducibly developed syncope during control tilt table testing; median time to syncope was 9.4+/-2.1 min. After normal saline infusion, none of the subjects developed syncope after 30 min upright. In the control tilt, there was an initial increase followed by a progressive decrease in low frequency power until syncope. Repeat tilt after normal saline administration demonstrates that low frequency power increased but the magnitude of initial change was blunted when compared with control. In addition, low frequency power increased during normal saline tilt sequence compared with the control tilt, during which it decreased. CONCLUSIONS Normal saline blunted low frequency power stimulation and prevented paradoxical low frequency power (sympathetic) withdrawal. Increasing intravascular volume with normal saline alters autonomic responses that may trigger neurally mediated syncope reflexes.
Collapse
Affiliation(s)
- T R Burklow
- Department of Cardiology, Children's National Medical Center, Washington, DC 20010, USA
| | | | | | | |
Collapse
|
17
|
Abstract
The evaluation of syncopal children or adolescents relies heavily on a thorough, detailed history and physical examination. All syncope associated with exercise or exertion must be considered dangerous. The ECG is mandatory, but other laboratory tests are generally of limited value unless guided by pertinent positives or negatives in the history and physical examination. The ECG allows screening for dysrhythmias, such as Wolff-Parkinson-White syndrome, heart block, and long QT syndrome, as well as hypertrophic cardiomyopathies and myocarditis. Tilt table testing can be useful in selecting therapy by demonstrating the physiologic response leading to syncope in an individual patient. The most common type of syncope in otherwise healthy children and adolescents is neurocardiogenic or vasodepressor syncope, which is a benign and transient condition. Because syncope can be a predictor of sudden cardiac death, it must be taken seriously, and appropriate screening must be performed.
Collapse
Affiliation(s)
- D A Lewis
- Division of Cardiology, Children's Hospital of Wisconsin, Milwaukee, USA
| | | |
Collapse
|
18
|
LaManca JJ, Peckerman A, Walker J, Kesil W, Cook S, Taylor A, Natelson BH. Cardiovascular response during head-up tilt in chronic fatigue syndrome. CLINICAL PHYSIOLOGY (OXFORD, ENGLAND) 1999; 19:111-20. [PMID: 10200892 DOI: 10.1046/j.1365-2281.1999.00154.x] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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. Stoke 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.
Collapse
Affiliation(s)
- J J LaManca
- CFS Cooperative Research Center, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, USA
| | | | | | | | | | | | | |
Collapse
|
19
|
Tercedor L, Díaz JF, Aguado MJ, Moreno E, Molina E, Alvarez M, Ramírez JA, Pérez de la Cruz JM, Azpitarte J. [The tilt-table test in assessing syncope of unknown origin: do differences exist between children and adults?]. Rev Esp Cardiol 1999; 52:189-95. [PMID: 10193172 DOI: 10.1016/s0300-8932(99)74893-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND AND OBJECTIVES Little is known about the differences between children and adults in the results of head-up tilt test. This study sought to investigate the potential differences concerning: a) the clinical profile and circumstances of spontaneous syncope; b) the overall diagnostic performance of the test, and c) the type of positive response obtained. MATERIAL AND METHODS We studied 31 children and 123 adults with unexplained syncope. If baseline test (tilting at 70 degrees for 30 min) resulted negative, it was repeated under isoprenaline low-dose infusion. RESULTS There were no differences in either clinical profile, except for severe traumatism more frequent in adults (25% vs. 3% in children; p < 0.05), or overall diagnostic performance (39% in children vs. 33% in adults; p = NS). However, the way the test rendered positive (via basal tilting in 92% of children vs. 50% in adults; p < 0.05) and the rate of cardioinhibitory response (42% in children vs 8% in adults; p < 0.01) were significantly different. CONCLUSIONS In this study children, in contrast to adults, rarely have a positive response in tilting under isoprenaline infusion. They also present a much higher rate of cardio-inhibitory response than adults.
Collapse
Affiliation(s)
- L Tercedor
- Unidad de Arritmias, Hospital Universitario Virgen de las Nieves, Granada
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
A substantial body of clinical evidence now supports an association between various forms of hypotension and both idiopathic chronic fatigue and the chronic fatigue syndrome (CFS). Patients with CFS have a high prevalence of neurally mediated hypotension, and open treatment of this autonomic dysfunction has been associated with improvements in CFS symptoms. Randomized trials are now in progress to evaluate the efficacy of treatments directed at neurally mediated hypotension in those with CFS patients, and the results of these trials should help guide more basic inquiries into the mechanisms of orthostatic intolerance in affected individuals.
Collapse
Affiliation(s)
- P C Rowe
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | | |
Collapse
|
21
|
Abstract
The management of unexplained syncope begins with the patient's history and physical examination, which are oriented to help separate benign from serious causes. Malignant etiologies are more likely to occur with exertional syncope. Cardiac causes should be considered, particularly cardiomyopathy, postoperative congenital heart disease, right ventricular dysplasia, anomalous coronary artery, pulmonary artery hypertension, myocarditis, long QT syndrome, and Wolff-Parkinson-White syndrome. Neurological and metabolic disorders may underlie a syncope episode. After malignant causes of syncope have been excluded and the diagnosis of neurocardiac syncope has been established, treatment strategies include behavior modification, salt and increased fluids, and pharmacological agents. Efficacious agents include beta-blockers, dysopyramide, fludrocortisones, and alpha agents. Yet, behavior modification alone may be as effective as salt or pharmacological therapy. Because the natural history of neurocardiac syncope in children is spontaneous resolution, it is appropriate to try the simple measures before introducing drug therapy.
Collapse
Affiliation(s)
- G S Wolff
- University of Miami Pediatrics Department, FL 33101, USA
| |
Collapse
|
22
|
Abstract
Syncope is caused by a global reversible reduction of blood flow to the brain. Three hemodynamic abnormalities can cause syncope: (1) a fall in systemic blood pressure because of ineffective control of peripheral vascular resistance, (2) an acute decrease in cardiac output, and (3) an acute increase in cerebrovascular resistance. Complicating the differential diagnosis of syncope are other causes of loss of consciousness, such as seizures, metabolic disorders, and psychiatric disorders, which may simulate syncope.
Collapse
Affiliation(s)
- H Kaufmann
- Department of Neurology, Mount Sinai School of Medicine, New York, New York, USA
| |
Collapse
|