Recurrent syncope as a chronic disease: preliminary validation of a disease-specific measure of functional impairment

Management of patients with Reflex Vasovagal syncope with a protocol involving a yoga maneuver Tadasana

BACKGROUND

There is no universally followed protocol for managing Reflex Vasovagal syncope (VVS).

METHODS

VVS patients were treated with a 2 step protocol. Step I - counseling, hydration, physiotherapy, and Tadasana Yoga maneuver. Patients with ≥2 VVS recurrences were given step II care - intensification of step I, elastic stockings,and pharmacotherapy. Follow-up included assessment by periodic functional status questionnaires.

RESULTS

157 patients (103 males & 54 females,mean age - 53 ± 20 years & mean LVEF - 62 ± 5%.) experienced 867 total events - 382 syncopal, and 485 near syncopal episodes over 14 ± 9 months. After step I protocol, the mean total, syncopal and near syncopal events declined from 5 ± 7 to 0.3 ± 1.2 (P < 0.0001), 3 ± 2 to 0.1 ± 0.4 (P < 0.0001) and 3 ± 6 to 0.2 ± 1.1 (P < 0.0001) respectively. Twenty (12.7%) patients had 53 event recurrences, 15- syncopal episodes in 7 and 38 near syncope events in 13. After step II, 5 patients had 14 events. At 33 ± 15 months, in 152 patients (96.8%) there were no recurrences and syncope was prevented in all (100%). The median total, syncopal and near syncopal events declined from 3 to 0,(p < 0.001) 2 to 0 (p < 0.001) and 1 to 0 (p < 0.001) respectively. There was an improvement in all the 3 quality of life parameters.

CONCLUSION

We demonstrate a simple and effective protocol that can be universally adopted to prevent VVS recurrences,with improvement in quality of life.

The Seventh Prevention of Syncope Trial (POST VII)-A randomized clinical trial of atomoxetine for the prevention of vasovagal syncope: Rationale and study design

BACKGROUND

Vasovagal syncope (VVS) is common, recurs, and is associated with markedly reduced quality of life, anxiety, and frequent injuries. The few pharmacological therapies for VVS proven to have a moderate benefit in reducing recurrences are limited to patients without coexisting conditions such as hypertension or heart failure. Although there is some data to suggest Atomoxetine, a norepinephrine reuptake transport inhibitor (NET), may be a promising treatment option, an adequately powered randomized placebo-controlled trial is needed.

STUDY DESIGN

POST VII is a multicenter, randomized, double-blind, placebo-controlled, crossover study that will randomize 180 patients with VVS and at least 2 syncopal spells in the preceding year to a target daily dose of atomoxetine 80 mg daily or to a matching placebo, with an observation period of 6 months in each phase and with a 1-week washout period between phases. The primary end point will be the proportion of patients with at least one syncope recurrence in each arm analyzed with an intention-to-treat approach. The secondary end points include total syncope burden, quality of life, cost, and cost-effectiveness.

POWER CALCULATIONS

Assuming a 33% relative risk reduction in syncope recurrence with atomoxetine, and a dropout rate of 16%, the enrollment of 180 patients will give an 85% power of reaching a positive conclusion about atomoxetine, with P = .05.

CONCLUSIONS

This will be the first adequately powered trial to determine whether atomoxetine is effective in preventing VVS. If proven effective, atomoxetine might become the first-line pharmacological treatment for recurrent VVS.

Current approach to the treatment of vasovagal syncope in adults

Vasovagal syncope (VVS) is the most common cause of transient loss of consciousness. Although not associated with mortality, it causes injuries, reduces quality of life, and is associated with anxiety and depression. The European and North American cardiac societies recently published syncope clinical practice guidelines. Most patients with VVS do well after specialist evaluation, reassurance and education. Adequate hydration, increased salt intake when not contraindicated, and careful withdrawal of diuretics and specific hypotension-inducing drugs are a reasonable initial strategy. Physical counterpressure maneuvers might be helpful but can be of limited efficacy in older patients and those with short or no prodromes. Orthostatic training lacks long term efficacy and is troubled by non-compliance. Yoga might be helpful, although the biomedical mechanism is unknown. Almost a third of VVS patients continue to faint despite these conservative measures. Metoprolol was not helpful in a pivotal randomized clinical trial. Fludrocortisone and midodrine significantly reduce syncope recurrences with tolerable side effects, when titrated to target doses. Pacing therapy with specialized sensors appears promising in carefully selected population who have not responded conservative measures. Cardioneuroablation may be helpful but has not been studied in a formal clinical trial.

Diagnostic sensitivity and cost per diagnosis of ambulatory cardiac monitoring strategies in unexplained syncope patients

Diagnosing cardiac pauses that could produce syncopal episodes is important to guide appropriate therapy. However, the infrequent nature of these episodes can make detection challenging with conventional monitoring (CM) strategies with short-term ECG monitors. Insertable cardiac monitors (ICMs) continuously monitor for arrhythmias but present a higher up-front cost. It is not well understood whether these higher costs are offset by the costs of repeat evaluation in CM strategies. We simulated the likelihood of diagnostic success and cost-per-diagnosis of pause arrhythmias with CM strategies compared to ICM monitoring. ICM device data from syncope patients diagnosed with pause arrhythmias was utilized to simulate patient pathways and diagnostic success with CM. We assumed that detected true pause episodes (≥5 seconds) were symptomatic and prompted a hospital encounter and further evaluation with CM. Subsequent true pause episodes in yet-undiagnosed patients triggered additional rounds of CM. Costs of monitoring were accrued at each encounter and represent the U.S. payer perspective. Cost per diagnosed patient was calculated as the total costs accrued for all patients divided by the number of patients diagnosed, across 1,000 simulations. During a mean 505±333 days of monitoring ICM detected 2.4±2.7 pause events per patient, with an average of 109±94 days until the first event. CM was projected to diagnose between 13.8% (24-hour Holter) and 30.2% (two 30-day monitors) of the ICM-diagnosed patients. Total diagnostic costs per ICM-diagnosed patient averaged $7,847, whereas in the CM strategies average cost-per-diagnosis ranged from $12,950±2,589 with 24-hour Holter to $32,977±14,749 for two 30-day monitors. Relative to patients diagnosed with pause arrhythmias via ICM, CM strategies diagnose fewer patients and incur higher costs per diagnosed patient.

A randomized study of yoga therapy for the prevention of recurrent reflex vasovagal syncope

AIMS

Vasovagal syncope (VVS) is a common cardiovascular dysautonomic disorder that significantly impacts health and quality of life (QoL). Yoga has been shown to have a positive influence on cardiovascular autonomics. This study assessed the effectiveness of yoga therapy on the recurrence of VVS and QoL.

METHODS AND RESULTS

We randomized subjects with recurrent reflex VVS (>3 episodes in the past 1 year) and positive head-up tilt test to guideline-directed therapy (Group 1) or yoga therapy (Group 2). Patients in Group 1 were advised guideline-directed treatment and Group 2 was taught yoga by a certified instructor. The primary endpoint was VVS recurrences and QoL. Between June 2015 and February 2017, 97 highly symptomatic VVS patients were randomized (Group 1: 47 and Group 2: 50). The mean age was 33.1 ± 16.6 years, male:female of 40:57, symptom duration of 17.1 ± 20.7 months, with a mean of 6.4 ± 6.1 syncope episodes. Over a follow-up of 14.3 ± 2.1 months Group 2 had significantly lower syncope burden compared with Group 1 at 3 (0.8 ± 0.9 vs. 1.8 ± 1.4, P < 0.001), 6 (1.0 ± 1.2 vs. 3.4 ± 3.0, P < 0.001), and at 12 months (1.1 ± 0.8 vs. 3.8 ± 3.2, P < 0.001). The Syncope functional score questionnaire was significantly lower in Group 2 compared with Group 1 at 3 (31.4 ± 7.2 vs. 64.1 ± 11.5, P < 0.001), 6 (26.4 ± 6.3 vs. 61.4 ± 10.7, P < 0.001), and 12 months (22.2 ± 4.7 vs. 68.3 ± 11.4, P < 0.001).

CONCLUSION

For patients with recurrent VVS, guided yoga therapy is superior to conventional therapy in reducing symptom burden and improving QoL.

Do implantable loop recorders impact the survival of patients with recurrent unexplained syncope?

Aim: This study compares the outcomes of patients who receive an implantable loop recorder (ILR) for unexplained syncope to a control group without the diagnostic device in German claims data. Methods  and materials: Patients with ILR were matched to a control group based on prior syncope events, age, gender and Charlson Comorbidity index (CCI). Survival, syncope hospitalizations, treatment and costs were compared. Results/conclusion: Four hundred and twelve ILR patients were matched with controls, mean age was 68, mean CCI was 2.7, 42% females. ILR patients lived on average 1.2 years longer than patients in the control group. Twenty-five percent of ILR patients received a therapeutic device compared with 5% in the control group. ILRs might help to diagnose and treat patients with positive impact on survival.

Burden of recurrent syncope and injuries and the usefulness of implantable cardiac monitors: insights from a nationwide longitudinal cohort analysis

Aim: The study assesses the burden and costs of recurring unexplained syncope and injuries and the effectiveness of implantable loop recorders. Methods: The English national hospital database (Hospital Episode Statistics) was retrospectively analyzed. Results: 12,002 patients were identified with repeated syncope hospitalizations. 25% of patients were hospitalized at least once again for syncope, 9% of the patients were hospitalized at least once for an injury, causing substantial costs. In the second analysis: 10,902 patients implanted with an implantable cardiac monitor were tracked. By year 3, hospitalizations due to syncope had dropped by 60% versus pre-implantable cardiac monitor (ICM) levels. Conclusion: This study shows a high rate of recurrent syncope admissions and a parallel burden of hospitalizations for injuries. Use of an ICM appears to reduce syncope hospitalizations.

A systematic review of dimensions evaluating patient experience in chronic illness

Background

Living with a chronic disease often means experiencing chronic treatments and regular multidisciplinary monitoring as well as a profound life-changing experience which may impact all aspects of a patients life. The patient experience of chronic disease is frequently assessed by patient reported measures (PRMs) which incorporate patients perspectives to better understand how illness, treatment and care impact the entirety of a patient’s life. The purpose of this review was to collect and review different kinds of available PRM instruments validated for chronic patients, to produce an inventory of explored concepts in these questionnaires and to identify and classify all dimensions assessing chronic patients experience.

Methods

A systematic review of PRM instruments validated for chronic patients was conducted from three databases (Medline, the Cochrane library, and Psycinfo). Articles were selected after a double reading and questionnaires were classified according to their targeted concept. Then, all dimensions of the questionnaires were clustered into different categories.

Results

107 primary validation studies of PRM questionnaires were selected. Five kinds of instruments were recorded: 1) Questionnaires assessing health related quality of life or quality of life; 2) Instruments focusing on symptoms and functional status; 3) Instruments exploring patients’ feelings and attitude about illness; 4) Questionnaires related to patients’ experience of treatment or healthcare; 5) Instruments assessing patients attitudes about treatment or healthcare. Twelve categories of dimensions were obtained from these instruments.

Conclusions

This review provided an overview of some of the dimensions used to explore chronic patient experience. A large PRM diversity exists and none of the reviewed and selected questionnaires covered all identified categories of dimensions of patient experience of chronic disease. Furthermore, the definition of explored concepts varies widely among researchers and complex concepts often lack a clear definition in the reviewed articles. Before attempting to measure chronic patient experience, researchers should construct appropriate instruments focusing on well-defined concepts and dimensions encompassing patient’s personal experience, attitude and adaptation to illness, treatment or healthcare.

Electronic supplementary material

The online version of this article (10.1186/s12955-019-1084-2) contains supplementary material, which is available to authorized users.

High Remission Rates in Vasovagal Syncope: Systematic Review and Meta-Analysis of Observational and Randomized Studies

OBJECTIVES

The aims of this study were to quantify the degree of improvement in vasovagal syncope after assessment and to identify predictive factors.

BACKGROUND

No treatments for vasovagal syncope have been proved effective, but patients in all prospective studies appear to show a reduction in the likelihood of fainting.

METHODS

A systematic review and meta-analysis was performed of studies published from 1993 through 2013. Inclusion criteria were: 1) vasovagal syncope frequency in the preceding 1 to 2 years; and 2) the proportion of subjects with syncope in at least the first follow-up year. Random-effects methods were used.

RESULTS

Of 338 screened studies, 17 were analyzed, with a mean of 112 subjects (range 9 to 511 subjects). In the preceding epoch, 97% of subjects fainted, with 2.6 ± 1.0 syncopal spells per year. In the follow-up year, the proportion of patients with ≥1 syncope recurrence was 677 of 1,912 (35.4%), and in the meta-analysis, the proportion of subjects fainting was only 0.44 (95% confidence interval: 0.41 to 0.46; p < 0.001). Subjects in larger studies were less likely to faint than those in randomized trials (relative risk: 0.35 vs. 0.55; p = 0.004). The probabilities of ≥1 syncope recurrence in the observational versus randomized studies were 0.30 (95% confidence interval: 0.24 to 0.37) and 0.54 (95% confidence interval: 0.46 to 0.62), respectively (p < 0.001). None of the degree of blinding, type of intervention, age, sex, and number of recent faints predicted the probability of syncope recurrence. Heterogeneity was very high in all analyses (I² = 60% to 96%).

CONCLUSIONS

The spontaneous remission rate in highly symptomatic syncope patients is high, and remission occurs in all types of studies. Improvement was more likely in larger and observational studies.

Rationale for the Assessment of Metoprolol in the Prevention of Vasovagal Syncope in Aging Subjects Trial (POST5)

BACKGROUND

Vasovagal syncope (VVS) is a common problem associated with a poor quality of life, which improves when syncope frequency is reduced. Effective pharmacological therapies for VVS are lacking. Metoprolol is a β-adrenergic receptor antagonist that is ineffective in younger patients, but may benefit older (≥40 years) VVS patients. Given the limited therapeutic options, a placebo-controlled clinical trial of metoprolol for the prevention of VVS in older patients is needed.

STRUCTURE OF STUDY

The POST5 is a multicenter, international, randomized, placebo-controlled study of metoprolol in the prevention of VVS in patients ≥40 years old. The primary endpoint is the time to first recurrence of syncope. Patients will be randomized 1:1 to receive metoprolol 25 to 100 mg BID or matching placebo, and followed up for 1 year. Secondary end points include syncope frequency, presyncope, quality of life, and cost analysis. Primary analysis will be intention to treat, with a secondary on-treatment analysis.

POWER CALCULATIONS

A sample size of 222, split equally between the groups achieves 85% power to detect a hazard rate of 0.3561 when the event rates are 50% and 30% in the placebo and metoprolol arms. Allowing for 10% dropout, we propose to enroll 248 patients.

IMPLICATIONS

This study will be the first adequately powered trial to determine whether metoprolol is effective in preventing VVS in patients ≥40 years. If effective, metoprolol may become the first line pharmacological therapy for these patients.

Management of vasovagal syncope: 2004

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.

Randomized clinical trial of an emergency department observation syncope protocol versus routine inpatient admission

STUDY OBJECTIVE

Older adults are frequently hospitalized from the emergency department (ED) after an episode of unexplained syncope. Current admission patterns are costly, with little evidence of benefit. We hypothesize that an ED observation syncope protocol will reduce resource use without adversely affecting patient-oriented outcomes.

METHODS

This randomized trial at 5 EDs compared an ED observation syncope protocol to inpatient admission for intermediate-risk adults (≥50 years) presenting with syncope or near syncope. Primary outcomes included inpatient admission rate and length of stay. Secondary outcomes included 30-day and 6-month serious outcomes after hospital discharge, index and 30-day hospital costs, 30-day quality-of-life scores, and 30-day patient satisfaction.

RESULTS

Study staff randomized 124 patients. Observation resulted in a lower inpatient admission rate (15% versus 92%; 95% confidence interval [CI] difference -88% to -66%) and shorter hospital length of stay (29 versus 47 hours; 95% CI difference -28 to -8). Serious outcome rates after hospital discharge were similar for observation versus admission at 30 days (3% versus 0%; 95% CI difference -1% to 8%) and 6 months (8% versus 10%; 95% CI difference -13% to 9%). Index hospital costs in the observation group were $629 (95% CI difference -$1,376 to -$56) lower than in the admission group. There were no differences in 30-day quality-of-life scores or in patient satisfaction.

CONCLUSION

An ED observation syncope protocol reduced the primary outcomes of admission rate and hospital length of stay. Analyses of secondary outcomes suggest reduction in index hospital costs, with no difference in safety events, quality of life, or patient satisfaction. Our findings suggest that an ED observation syncope protocol can be replicated and safely reduce resource use.

The effect of paediatric syncope on health-related quality of life

BACKGROUND

Syncope is common in children and adolescents and most commonly represents neurocardiogenic syncope. No information has been reported regarding the effect of syncope on health-related quality of life in children.

METHODS

This was a retrospective cohort study of patients seen in the Heart Institute Syncope Clinic at Cincinnati Children's Hospital Medical Center between July, 2009 and June, 2010. Health-related quality of life was assessed using the PedsQL™ tool. PedsQL™ scores were compared with both healthy historical controls and historical controls with chronic illnesses.

RESULTS

A total of 106 patients were included for analysis. In all, 90% were Caucasian and 63% were girls. The median age was 15.1 years (8.2-21.6). Compared with healthy controls, patients had lower PedsQL™ scores: Total score (75.2 versus 83.8, p < 0.0001); Physical Health Summary (78.8 versus 87.5, p < 0.0001); Psychosocial Health Summary (73.9 versus 81.9, p < 0.001), Emotional Functioning (68.9 versus 79.3, p < 0.001); and School Functioning (66.4 versus 81.1, p < 0.001). No difference was seen in Social Functioning (86.2 versus 85.2, p = 0.81). Patients also had lower PedsQL™ Total scores than patients with diabetes mellitus (p < 0.0001) and similar scores to patients with asthma, end-stage renal disease, obesity, and structural heart disease.

CONCLUSION

Children with syncope, although typically benign in aetiology, can have low health-related quality of life.

Patient-reported physical activity questionnaires: a systematic review of content and format

Background

Many patients with chronic illness are limited in their physical activities. This systematic review evaluates the content and format of patient-reported outcome (PRO) questionnaires that measure physical activity in elderly and chronically ill populations.

Methods

Questionnaires were identified by a systematic literature search of electronic databases (Medline, Embase, PsychINFO & CINAHL), hand searches (reference sections and PROQOLID database) and expert input. A qualitative analysis was conducted to assess the content and format of the questionnaires and a Venn diagram was produced to illustrate this. Each stage of the review process was conducted by at least two independent reviewers.

Results

104 questionnaires fulfilled our criteria. From these, 182 physical activity domains and 1965 items were extracted. Initial qualitative analysis of the domains found 11 categories. Further synthesis of the domains found 4 broad categories: 'physical activity related to general activities and mobility', 'physical activity related to activities of daily living', 'physical activity related to work, social or leisure time activities', and '(disease-specific) symptoms related to physical activity'. The Venn diagram showed that no questionnaires covered all 4 categories and that the '(disease-specific) symptoms related to physical activity' category was often not combined with the other categories.

Conclusions

A large number of questionnaires with a broad range of physical activity content were identified. Although the content could be broadly organised, there was no consensus on the content and format of physical activity PRO questionnaires in elderly and chronically ill populations. Nevertheless, this systematic review will help investigators to select a physical activity PRO questionnaire that best serves their research question and context.

Lower limb-localized vascular phenomena explain initial orthostatic hypotension upon standing from squat

The cause(s) of initial orthostatic hypotension (transient fall in blood pressure within 15 s upon active rising) have not been established. We tested the hypothesis that this hypotension is due to local vascular phenomena in contracting leg muscles from the brief effort of standing up. Seventeen young healthy subjects (2 male and 15 female, 22.5 ± 1.0 years) performed an active rise from resting squat after a 10-s squat, a 1-min squat, or a 5-min squat. Beat-by-beat arterial blood pressure, cardiac output, heart rate, and stroke volume (Finometer finger photoplethysmography) and right common femoral artery blood flow (Doppler and Echo ultrasound) were recorded. Data are means ± SE. Quiet standing before squat represented baseline. Peak increases in lower limb and total vascular conductance (ml·min−1·mmHg−1) upon standing were not different within squat conditions (10-s squat, 50.0 ± 12.4 vs. 44.3 ± 5.0; 1-min squat, 54.7 ± 9.2 vs. 50.5 ± 4.5; 5-min squat, 67.4 ± 13.7 vs. 58.8 ± 3.9; all P > 0.574). Mean arterial blood pressure (in mmHg) fell to a nadir well below standing baseline in all conditions despite increases in cardiac output. The hypotension predicted by the increase in leg vascular conductance accounted for this hypotension [observed vs. predicted (in mmHg): 10-s squat, −17.1 ± 2.1 vs. −18.3 ± 5.5; 1-min squat, −22.0 ± 3.8 vs. −25.3 ± 4.9; 5-min squat, −28.3 ± 4.0 vs. −29.2 ± 6.7]. We conclude that rapid contraction induced dilation in leg muscles with the effort of standing, along with a minor potential contribution of elevated lower limb arterio-venous pressure gradient, outstrips compensatory cardiac output responses and is the cause of initial orthostatic hypotension upon standing from squat.

Design and use of a quantitative scale for measuring presyncope

INTRODUCTION

Vasovagal syncope is common and distressing. One important symptom is presyncope, but there are no clinimetric measures of this. We developed the Calgary Presyncope Form (CPF) and used it to test whether metoprolol reduces presyncope in a randomized trial.

METHODS

The CPF captures the frequency, duration, and severity of presyncope. We administered it to participants in the Prevention of Syncope Trial (POST), a randomized clinical trial that tested the hypothesis that metoprolol reduces syncope and presyncope in adult patients with vasovagal syncope.

RESULTS

The CPF was completed by 44 patients on metoprolol and 39 patients on placebo, of a total of 208 subjects. Completion of the CPF for each of the threedimensions was 84-87% in the 83 respondents. Results were centrally distributed in duration and severity dimensions, but not in frequency. Patients had a median of 1.2 presyncopal spells per day, with a median moderate severity, lasting a median 10 minutes. The 3 scales were statistically independent of each other. These results were independent of subject age, and results in all 3 dimensions were stable over the observation period. There was no significant difference between patients on metoprolol and placebo in any dimension.

CONCLUSION

The 3-dimensional CPF is simple, easy to use, stable over time, measures 3 independent variables, and documents that metoprolol does not reduce presyncope.

Level of psychosocial impairment predicts early response to treatment in vasovagal syncope

AIM

To investigate whether levels of psychosocial impairment and psychological distress at diagnosis in those with vasovagal syncope (VVS) predict subsequent response to conventional treatment.

METHODS AND RESULTS

This is a prospective, observational new patient cohort study, which includes consecutive patients with head-up tilt-confirmed VVS (September 2004-March 2006). Subjects completed the Hospital Anxiety and Depression Scale, State and trait anxiety inventory, and an Adapted Syncope Functional Status Questionnaire at diagnosis and at 3 months. A total of 108 participants [mean (SD) age 52 (21) years, 70.4% were female] completed baseline assessments. Response status was ascertained for 103 individuals; 70 were responders and 33 non-responders. Eighty-three of 103 participants (81%) completed the follow-up questionnaires. At follow-up, compared with responders, non-responders reported higher levels of Impairment (P = 0.001), negative cognitions (P = 0.01), and depression scores (P = 0.006). At diagnosis those who ultimately did not respond to treatment reported significantly higher levels of Impairment (P < 0.001) and negative cognitions (P = 0.03). Those who did not respond to treatment were significantly more depressed (P = 0.001) with higher Trait anxiety scores (P = 0.007). Multivariate analysis confirmed increased impairment predicted poor response status (z = 9.82, P = 0.002) with participants being 3% more likely to be a non-responder with each 1% increase in self-reported level of impairment.

CONCLUSION

Higher levels of psychosocial impairment reliably predict non-response to treatment, suggesting that psychological factors have an important role in VVS. Screening individuals at diagnosis may enable identification of those at risk of non-response and delivery of targeted psychological interventions to reduce the impact of VVS and its sequelae.

Management of initial orthostatic hypotension: lower body muscle tensing attenuates the transient arterial blood pressure decrease upon standing from squatting

IOH (initial orthostatic hypotension) comprises symptoms of cerebral hypoperfusion caused by an abnormally large transient MAP (mean arterial pressure) decrease 5–15 s after arising from a supine, sitting or squatting position. Few treatment options are available. In the present study, we set out to test the hypothesis that LBMT (lower body muscle tensing) attenuates IOH after rising from squatting and its symptoms in daily life. A total of 13 IOH patients (nine men; median age, 27 years) rose from squatting twice, once with LBMT and once without. In addition, seven healthy volunteers (five men; median age, 27 years) were studied in a cross-over study design. They stood up from the squatting position three times, once combined with LBMT. Blood pressure (Finometer) was measured continuously, and CO (cardiac output) by Modelflow and TPR (total peripheral resistance) were computed. MAP, CO and TPR were compared without and with LBMT. Using a questionnaire, the perceived effectiveness of LBMT in the patients' daily lives was evaluated. With LBMT, the minimal MAP after standing up was higher in both groups (19 mmHg in patients and 13 mmHg in healthy subjects). In healthy subjects, the underlying mechanism was a blunted TPR decrease (to 47% compared with 60%; P<0.05), whereas in the patients no clear CO or TPR pattern was discernible. During follow-up, eight out of ten patients using LBMT reported fewer IOH symptoms. In conclusion, LBMT is a new intervention to attenuate the transient blood pressure decrease after standing up from squatting, and IOH patients should be advised about the use of this manoeuvre.

Reliability, validity and responsiveness of the syncope functional status questionnaire

BACKGROUND

Patients with transient loss of consciousness (TLOC) have poor health-related quality of life (HR-QoL).

OBJECTIVE

To test the reliability, validity, and responsiveness of the disease-specific Syncope Functional Status HR-QoL Questionnaire (SFSQ), which yields two summary scales--impairment score (IS) and fear-worry score (FWS).

DESIGN

Cohort-study.

PARTICIPANTS

503 adult patients presenting with TLOC.

MEASUREMENTS

HR-QoL was assessed using the SFSQ and the Short Form-36 (SF-36) after presentation and 1 year later. To test reliability, score distributions, internal consistency, and test-retest reliability were assessed. To assess validity, scores on the SFSQ and the SF-36 were compared. Clinical validity was tested using known-group comparison. Responsiveness was assessed by comparing changes in SFSQ scores with changes in health status and clinical condition.

RESULTS

Response rate was 82% at baseline and 72% at 1-year follow-up. For all scales the full range of scores was seen. Score distributions were asymmetrical. Internal consistency was high (alpha = 0.88 for IS, 0.92 for FWS). Test-retest reliability was moderate to good for individual items and high for summary scales (inter-class correlation = 0.78 for both IS and FWS). Correlations between SFSQ scores and the SF-36 were modest. The SFSQ did not discriminate between patients differing in age and gender but did discriminate between patients differing in number of episodes and comorbid conditions. Changes in SFSQ scores were related to changes in health status and the presence of recurrences but did not vary by TLOC diagnosis.

CONCLUSION

The SFSQ is an adequately reliable, valid, and responsive measure to assess HR-QoL in patients with TLOC.

Quality of life within one year following presentation after transient loss of consciousness

The purpose of this study was to examine (1) changes in quality of life (QoL) within 1 year after presentation with transient loss of consciousness (TLOC) and (2) which factors are predictive of these changes. This study was part of the Fainting Assessment Study (FAST), which assessed diagnostic strategies in patients with TLOC. Adult patients presenting to Academic Medical Center, Amsterdam, The Netherlands, with TLOC were included in the study. QoL was assessed with the generic Short Form 36 and the disease-specific Syncope Functional Status Questionnaire at presentation and 1 year of follow-up. Of 468 included patients, 82% completed questionnaires at presentation and 72% after 1-year follow-up. QoL improved on 7 of 8 subscales of the Short Form 36 and on all summary scales of the Syncope Functional Status Questionnaire. Older age, recurrence, higher level of co-morbidity, and a neurologic or psychogenic diagnosis were predictive of poorer QoL. In conclusion, QoL in patients with TLOC improves significantly over time. Physicians should particularly pay attention to patients who are older, have recurrent episodes, a neurologic or psychogenic diagnosis, and a higher level of co-morbidity because these patients are vulnerable to a relatively poorer QoL.

Initial orthostatic hypotension: review of a forgotten condition

Several studies have shown that standing up is a frequent (3-10%) trigger of loss of consciousness both in young and old subjects. An exaggerated transient BP (blood pressure) fall upon standing is the underlying cause. IOH (initial orthostatic hypotension) is defined as a transient BP decrease within 15 s after standing, >40 mmHg SBP (systolic BP) and/or >20 mmHg DBP (diastolic BP) with symptoms of cerebral hypoperfusion. It differs distinctly from typical orthostatic hypotension (i.e. BP decrease >20 mmHg SBP and/or >10 mmHg DBP after 3 min of standing) as the BP decrease is transient. Only continuous beat-to-beat BP measurement during an active standing-up manoeuvre can document this condition. As IOH is only associated with active rising, passive tilting is of no diagnostic value. The pathophysiology of IOH is thought to be a temporal mismatch between cardiac output and vascular resistance. The marked decrease of vascular resistance during rising is similar to that observed at the onset of leg exercise and is absent during head-up tilting. It is attributed to vasodilatation in the working muscle through local mechanisms. Standing up causes an initial increase in venous return through the effects of contraction of leg and abdominal muscles. The consequent sudden increase in right atrial pressure may contribute to the fall in systemic vascular resistance through a reflex effect. This review alerts clinicians and clinician scientists to a common, yet often neglected, condition that occurs only upon an active change of posture and discusses its epidemiology, pathophysiology and management.

The role of psychological factors in response to treatment in neurocardiogenic (vasovagal) syncope

AIMS

Studies have established a link between vasovagal syncope (VVS) and anxiety, depression, and functional impairment. This study examines the prevalence of psychological problems in patients with VVS and whether non-responders are psychologically different from those whose symptoms respond to conservative treatment.

METHODS AND RESULTS

Subjects with tilt-confirmed VVS completed the hospital anxiety and depression scale (HADS) (measures current levels of anxiety and depression) and the syncope functional status questionnaire (SFSQ) (syncope-specific quality-of-life measure) and participated in a semi-structured interview to ascertain potential triggers, thought content, and coping strategies. In this study, 41 subjects participated. There was no difference in gender and age duration of symptoms between responders (n=21) and non-responders (n=20). Non-responders were significantly more anxious (P=0.003) and depressed (P=0.003) and had a higher level of state (P=0.008) and trait (P=0.004) anxiety than responders. Non-responders reported more fear/worry (P=0.02), a significantly higher degree of impairment owing to syncope (P=0.01), and a greater number of perceived triggers (P=0.039); on average, participants reported eight negative thoughts about the consequences of VVS, with particular emphasis on threats of physical harm or death. Non-responders had higher levels of avoidance/protection coping and rumination.

CONCLUSION

This study has confirmed that patients with VVS have a significant degree of psychological distress, which is worthy of consideration in its own right, out with management purely aimed at reducing syncopal or pre-syncopal symptoms. Further, this distress may actually influence the natural history of what is a chronic relapsing condition and may in fact be more relevant to the patient than the number of syncopal episodes that they are experiencing.

Clinical factors associated with quality of life in patients with transient loss of consciousness

INTRODUCTION

Transient loss of consciousness (TLOC) is common and can be lethal. Although the patients with the most prevalent causes of TLOC have a benign prognosis, morbidity is considerable. Aim of this article, therefore, was to compare the generic quality of life (QoL) of patients presenting with TLOC with that of the general population, to compare the disease-specific QoL with that of an American referral sample, and to examine which sociodemographic and clinical factors are associated with QoL in these patients.

METHODS

This study was part of the fainting assessment study (FAST), which assessed diagnostic strategies for adult patients presenting with TLOC to the Academic Medical Center Amsterdam, between February 2000 and May 2002. The generic short form-36 (SF-36) health survey and the disease-specific syncope functional status questionnaire (SFSQ) were used to assess QoL.

RESULTS

Of 468 included patients, 82% completed the questionnaires. Patients with TLOC scored poorer on all scales of the SF-36 than the Dutch population, with effect sizes ranging from 0.43 to 1.11 (>0.5 = moderate effect; >0.8 = large effect). The SFSQ indicated mean impairment in 33% of the listed activities (such as driving). Female gender, higher level of comorbidity, shorter duration of complaints, having had more than one syncopal episode, and the presence of presyncopal episodes were associated with poorer QoL.

CONCLUSION

TLOC seriously affects QoL, especially in patients with a recent onset of clinical symptoms and those suffering from both syncopal and presyncopal episodes.

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

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.

Neurocardiogenic syncope: latest pharmacological therapies

Neurocardiogenic syncope is a neurally mediated disorder and is a common cause of syncope. The goal of treatment is to prevent recurrences with the aim of improving quality of life and reducing morbidity. Reassurance, in some cases, may suffice. In others, augmenting central blood volume by increasing fluid and/or salt intake is effective. The role of non-pharmacological physical manoeuvres is increasingly recognised, given the increasing clinical trial data supporting their efficacy. This review summarises the clinical evidence for a variety of pharmacological agents. Of these, midodrine appears to have yielded the most consistent favourable outcome. Its use, however, should be reserved for patients with recurrent and refractory syncope.

A randomised prospective comparison of three protocols for head-up tilt testing and carotid sinus massage

INTRODUCTION

Head-up tilt testing is an important tool in the diagnosis of syncope. Several different protocols are in use. This study aimed to compare three different protocols in an unselected population of patients with recurrent unexplained syncope and to assess long-term outcome using conventional tilt-directed management or implantable loop recorder (Reveal Plus)-directed management, allowing evaluation of the sensitivity and specificity of the technique.

METHODS

Patients with recurrent unexplained syncope were randomized to one of three tilt protocols: Drug-free--70 degree tilt, 45 min, CSM at 5 and 45 min. GTN--70 degree tilt, 35 min, CSM at 5 min, 400 microg of glyceryl trinitrate spray administered sublingually at 20 min. Adenosine--70 degree tilt, 5 min, CSM when blood pressure is stable in upright position, adenosine bonus at 150 microg/kg after CSM. Tilts were terminated at the onset of syncope, when systolic BP reached 60 mm Hg, or in the presence of prolonged hypotension (> 3 min systolic BP < 80 mm Hg). Appropriate therapies were commenced according to the result of the tilt test. All patients without a definite indication for immediate cardiac pacing (asystolic tilt) were randomized to conventional management or ILR implantation. Recurrent syncopal events were compared to tilt outcome, allowing estimation of sensitivity and specificity.

RESULTS

Of 214 patients, aged 68+/-18 years, 55% were female, with a median of three previous syncopes. 13 patients received pacemakers due to asystolic syncope during tilt testing. The proportion of VASIS classification diagnoses was similar with each protocol; however more positive diagnoses resulted from the GTN protocol (p=0.0013). 47% of patients achieved a diagnosis with tilt testing. We were able to correlate a subsequent spontaneous syncope to tilt result in 36 patients (18%). Heart rate during a spontaneous event was similar to that obtained during tilt testing (+/- 10%) in 55% of cases. Sensitivities for combined protocols, adenosine, GTN, and drug-free protocols were 50%, 50%, 100%, and 21%, respectively. Specificities were 85%, 100%, 75%, and 71%, respectively.

CONCLUSIONS

A high diagnosis rate for unexplained syncope can be achieved with tilt testing. The GTN protocol resulted in significantly more diagnoses than the other compared protocols with good sensitivity and adequate specificity. Sensitivity of the drug-free tilt test was lower than drug-augmented tilt testing.

The clinical impact of implantable loop recorders in patients with syncope

AIMS

Implantable loop recorders (ILR) provide an opportunity to record ECG data from a spontaneous syncopal event. We conducted a randomized study to investigate the impact of the Reveal Plus ILR on an unselected population of patients with recurrent syncope. Initial follow-up (at least 6 months) did not demonstrate a reduction in syncopal events or an improvement in quality of life. We report the planned extension of follow-up to 18 months.

METHODS AND RESULTS

All patients presenting acutely with recurrent unexplained syncope over a 16-month period, following a basic clinical work-up, were randomized to receive the ILR or conventional investigation and management. A total of 421 patients presented, 201 were eligible, median age 74, (IQ range 61-81) 54% female, with median syncopes 3 (IQ range 2-6). Median follow-up 17 months (IQ range 9-23). 42 (43%) of ILR patients and 8 (6%) of conventional patients received an ECG diagnosis (hazard ratio 6.53, 95% CI 3.73-11.4, P<0.001). Time to second syncope was significantly longer for ILR patients, although of borderline significance (P=0.04). A greater variety of diagnoses and treatments were seen in ILR patients. ILR patients had fewer post-randomization investigations and fewer days in hospital; however, cost savings were not statistically significant. There was improved quality of life in the ILR group (visual analogue scales, P=0.03) for general wellbeing. Overall mortality was 12% with no difference between the two groups.

CONCLUSION

Investigation by the ILR significantly increases the diagnostic rate and ECG directed treatments in a typical unselected syncopal population. Long-term follow-up has demonstrated a significant subsequent reduction in syncopal events with improved quality of life.

Leg crossing, muscle tensing, squatting, and the crash position are effective against vasovagal reactions solely through increases in cardiac output

Tensing of lower body muscles without or with leg crossing (LBMT, LCMT), whole body tensing (WBT), squatting, and sitting with the head bent between the knees (“crash position,” HBK) are believed to abort vasovagal reactions. The underlying mechanisms are unknown. To study these interventions in patients with a clinical history of vasovagal syncope and a vasovagal reaction during routine tilt table testing, we measured blood pressure (BP) continuously with Finapres and derived heart rate, stroke volume, cardiac output (CO), and total peripheral resistance using Modelflow. In series A ( n = 12) we compared LBMT to LCMT. In series B ( n = 9), WBT was compared with LCMT. In series C ( n = 14) and D ( n = 9), we tested squatting and HBK. All maneuvers caused an increase in BP, varying from a systolic rise from 77 ± 8 to 104 ± 18 mmHg ( P < 0.05) in series A during LBMT to a rise from 70 ± 10 to 123 ± 9 mmHg ( P < 0.05) in series B during LCMT. In each maneuver, the BP increase started within 3–5 s from start of the maneuver. In all maneuvers, there was an increase in CO varying from 54 ± 12% of baseline to 94 ± 21% in WBT to a rise from 65 ± 17% to 110 ± 22% in LCMT in series A. No maneuver caused significant change in total peripheral resistance. We conclude that the mechanism underlying the effects of these maneuvers is exclusively an increase in CO.

[Quality of life in patients with vasovagal syncope. Clinical parameters influence]

BACKGROUND AND OBJECTIVE

The prevalence and morbidity of the vaso-vagal syncope are well-known. With the intention of measuring the Quality of Life (QoL) of patients with vaso-vagal syncope, as well as age and gender influence, we have used the Spanish version of Short form 36 (SF-36) questionnaire in those patients and have compared it with the general population and with patients with heart failure.

PATIENTS AND METHOD

All consecutive patients with vaso-vagal syncope submitted for head-up tilt test performance from January 2001 to December 2002 were included. SF-36 was self-administered prior to the head-up tilt test.

RESULTS

Two hundred and seventy one patients were included (50.5% females). In these patients, QoL scores were lower than those of the Spanish general population and similar to those in patients with heart failure. Women's scores were lower in eight dimensions, and only four were lower in men's. Women QoL was worst than men's (p < 0.05). Age had a negative influence on the eight dimensions of SF-36, especially in women. The number of syncopes was the most influential clinic parameter on the QoL of such patients.

CONCLUSIONS

In our series, patients suffering from vaso-vagal syncope had a poor QoL when compared with heart failure or control populations. Women had lower QoL than men, and there was an age-related worsening in both men and women. Our data show that the number of syncopes is the clinic parameter having the best correlation with QoL.

Management of vasovagal syncope: controlling or aborting faints by leg crossing and muscle tensing

BACKGROUND

Posture-related vasovagal syncope is by far the most frequent cause of transient loss of consciousness, and present pharmacological and cardiac pacing treatment remains unsatisfactory. A simple maneuver to prevent or diminish vasovagal reactions would be beneficial.

METHODS AND RESULTS

Twenty-one patients with recurrent syncope (age 17 to 74 years, 11 males) who were referred for routine tilt-table testing and had a positive test were included. They were instructed to perform leg crossing and muscle tensing for at least 30 seconds at the onset of a tilt table-provoked impending faint. Continuously measured blood pressure and heart rate at nadir and during the maneuver were compared. Ten months after the test, a telephone follow-up was performed. The physical counter-maneuver, performed in 20 of 21 subjects, increased blood pressure and heart rate. Systolic blood pressure rose from 65+/-13 to 106+/-16 mm Hg (mean+/-SD, P<0.001), and diastolic blood pressure rose from 43+/-9 to 65+/-10 mm Hg (P<0.001). During the maneuver, prodromal symptoms disappeared in all patients, and none lost consciousness. After terminating the maneuver, symptoms did not return in 5 subjects during the test. At follow-up, 13 of 20 patients reported that they applied the maneuver in daily life and benefited from it.

CONCLUSIONS

Leg crossing combined with tensing muscles at the onset of prodromal symptoms can postpone and in some subjects prevent vasovagal syncope.

The relationship between health-related quality of life and frequency of spells in patients with syncope

Chronic syncope has a wide range of symptom burden, and anecdotal data suggest substantial but variable physical and psychosocial morbidity. We hypothesized that health-related quality of life (HRQL) is impaired in syncope patients and the degree of impairment is proportional to syncope frequency. The EuroQol EQ-5D was completed by 136 patients (79 female and 57 male) with mean age 40 (SD = 17) prior to assessment. HRQL was substantially impaired in syncope patients compared to population norms in all five dimensions of health measured by the EQ-5D. In patients with six or more lifetime syncopal spells there was a significant (P < 0.001) negative relationship between the frequency of spells and overall perception of health, which was not evident in those who had a history of less than six lifetime spells. These relationships were maintained after controlling for comorbid conditions.

Pacing to prevent vasovagal syncope

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.

Effect of dual-chamber pacing with automatic rate-drop sensing on recurrent neurally mediated syncope

We tested the hypotheses that a dual-chamber pacemaker that paces when intrinsic rate drops abruptly would reduce the number of syncopal spells and improve the quality of life in patients with highly recurrent neurally mediated syncope. Twelve patients with highly frequent neurally mediated syncope and at least 1 syncopal spell after tilt testing received dual-chamber pacemakers with automatic rate-drop sensing. The pacemakers were implanted 17+/-26 months after tilt testing, and the patients then were followed for 12+/-2 months. We compared the time to the first recurrence of syncope, syncope frequency, and quality of life for the 2 periods between tilt testing and pacemaker implantation, and between implantation and last follow-up. Only 6 of 12 patients fainted after pacemaker insertion. The median time to syncope recurrence before and after pacing was 7 days and 5.3 months, respectively. The geometric mean frequency of faints before and after pacing was 5.0 spells/month (95% confidence interval 2.7 to 9.2) and 0.30 spells/month (95% confidence interval 0.2 to 0.4), p <0.001. After 6 months the mean perception of health on the 100-point EuroQol scale rose from 55 to 82 (p = 0.003), and the general health perception on the SF-36 scale rose from 51 to 72 (p = 0.005). Permanent dual-chamber pacing with automatic rate-drop sensing in patients with highly frequent syncope is associated with a marked reduction in the likelihood of syncope and a marked improvement in quality of life.

Timing of first recurrence of syncope predicts syncopal frequency after a positive tilt table test result

OBJECTIVES

This study sought to determine whether the time to first recurrence of syncope after a positive isoproteremol-tilt table test result accurately predicts the eventual frequency of syncope.

BACKGROUND

Both patient care and future clinical trials involving patients with neuromediated syncope will require a simple measure that reflects the frequency of syncope. The time from tilt table testing to the first recurrence of syncope might be such a measure.

METHODS

A cohort of 46 patients with syncope, in a university outpatient clinic, who had at least one syncopal spell after a positive isoproterenol-tilt table test result were followed up for up to 6.5 years (mean [+/-SD] 48 +/- 14 months). The time from tilt table testing to the first recurrence of syncope was correlated.

RESULTS

A total of 40 of 46 patients had more than one recurrent spell, with a median of eight recurrent spells. The time to the first syncopal spell predicted the frequency of spells with r = -0.79 (p < 0.001), whereas the time to the second spell predicted the frequency with r = -0.92 (p < 0.001). Patients who fainted within 1 month of tilt testing had a geometric mean frequency of 1.35 spells/month (95% confidence limits 0.49, 3.74) compared with patients who fainted 1 to 24 months after testing (0.12 spells/months; 95% confidence limits 0.07 to 0.18, p < 0.001). Finally, the frequency of syncopal spells bore no relation to the duration of follow-up.

CONCLUSIONS

The time to the first recurrent spell predicts the frequency of syncopal spells after a positive tilt table test result, and the instantaneous risk of syncope is constant.

Psychiatric illness and syncope

Studies have reported a high prevalence of psychiatric illness in patients with syncope, particularly among those with syncope of unknown etiology. Although mortality rates for patients with syncope and psychiatric disorders tend to be lower than for patients with cardiac cause for syncope, treatment of these psychiatric illnesses appears to result in lower rates of recurrence of the symptoms. The authors recommend an assessment for psychiatric illness in those patients in whom the initial evaluation does not suggest an organic cause for syncope. Further studies are needed to elucidate the pathophysiologic mechanisms for syncope and the effects of treatment of psychiatric illness on recurrence of syncope.

North American Vasovagal Pacemaker Study: study design and organization

The North American Vasovagal Pacemaker Study is an ongoing multicenter randomized, clinical trial that assesses the efficacy of dual chamber pacing utilizing rate drop sensing in patients with frequent syncopal spells. Patients are eligible if they have had at least six syncopal spells and a positive tilt table test, or a recurrence of syncope within 6 months of a positive tilt test. The tilt table test must have provoked a relative bradycardia. Patients are randomized to receive a Medtronic Thera DR with rate drop sensing, or to continue on their usual therapy. All patients complete a log of their presyncopal and syncopal spells daily, and are contacted every 2 months. The primary outcome measure is the time to the first recurrence of syncope. The goal of the main study is to recruit 284 patients in 3 years with a final fourth year of follow-up; this will result in an 80% chance of detecting a 30% reduction in the risk of syncope. A pilot study is under way with the aim to recruit 60 patients over a period of 2 years with a final third year of follow-up. Recruitment began in July 1995 and 47 patients have been enrolled to date.

Effect of beta blockers on the time to first syncope recurrence in patients after a positive isoproterenol tilt table test

Isoproterenol-headup tilt table testing provides a diagnosis of neuromediated syncope in many patients who faint. The involvement of beta-adrenoceptor stimulation in the provocation of syncope suggests that beta blockers might chronically prevent syncope. To assess this, a cohort of 153 syncope patients (age 39 +/- 20 years) underwent baseline assessment of demographic variables, symptomatic burden, and hemodynamic and clinical responses to tilt testing. Fifty-two patients then received beta blockers, and 101 did not receive drug therapy. The primary outcome was the time to the first recurrent syncopal spell. Actuarial survival analysis was used. Syncope recurred in 17 of 52 patients who received beta blockers and in 28 of 101 patients who were untreated. The actuarial probability of remaining free of syncope was similar in both groups. For example, the probability of remaining free of syncope 12 months following the tilt test was 0.72 in both populations. Thus, treatment with beta blockers may not have a significant effect in preventing syncope recurrence following a positive tilt test.

Risk factors for syncope recurrence after a positive tilt-table test in patients with syncope

BACKGROUND

Recent work with head-up tilt-table testing has suggested that many patients with syncope may have recurrent neurally mediated episodes of bradycardia, hypotension, or both. The purpose of this study was to determine how to identify patients at high risk of a recurrence of neuromediated syncope after a positive isoproterenol/tilt-table test.

METHODS AND RESULTS

A cohort of 101 drug-free patients in a university hospital outpatient clinic with syncope and a positive isoproterenol/tilt-table test underwent baseline assessment of demographic variables, symptomatic burden, and hemodynamic and clinical responses to tilt testing. The primary outcome measure was the time to the first recurrent syncopal spell. The actuarial probabilities of remaining syncope free after 1 and 2 years were 72% and 60%, respectively. Multivariate proportional hazards analysis demonstrated that the most powerful predictor of a recurrence of syncope was the logarithm of the number of preceding syncopal spells (P<.001). Other predictive variables included the duration of syncopal symptoms, tilt test symptomatic outcome, and trough heart rate. The probability of a recurrence of syncope also varied with the logarithm of the frequency of preceding spells (P=.008). The median frequency of pretest spells was 0.3/month; after the tilt test, the median frequency dropped approximately 90% to 0.03 per month.

CONCLUSIONS

The risk of a recurrence of syncope after a positive tilt-table test can be predicted with simple pretest and intratest variables.