Yield and cost-effectiveness of tilt table tests combined with video-EEG.

To study the outcomes of a series of consecutive tilt table tests combined with video-EEG (TTVE) at a single center, and assess their cost-effectiveness compared with other neurophysiological tests. We retrospectively reviewed medical records of patients who underwent TTVE studies between March 1st, 2013 to April 1st, 2018. Detailed clinical history, including patient demographics, reasons for referral, anti-seizure medications, and neurophysiological studies obtained prior to the TTVE studies were extracted from chart reviews. The fee for each neurophysiological test was identified from the Centers for Medicare & Medicaid Services. Fifty-two patients underwent TTVE studies. Thirteen patients (25%) were diagnosed with vasovagal syncope, two (3.8%) were diagnosed with postural orthostatic tachycardia syndrome, and three (5.8%) had psychogenic non-epileptic events during the test. Four out of 12 patients stopped anti-seizure medication(s) after the TTVE. Prior to referral for TTVE, an average of $3,748 per person was spent on neurophysiological tests, which were inconclusive. The average fee for one TTVE test was $535.32, and the fee per test affecting diagnosis or management (defined as the cost divided by the yield of the test) was $1,547. The TTVE test is cost-effective in evaluating refractory episodes of loss of consciousness, atypical of epileptic seizures. In addition to diagnosing syncope, TTVE can be valuable in identifying psychogenic events.

Simulation training for medical emergencies in the dental setting using an inexpensive software application.

INTRODUCTION: Every dental provider needs to be educated about medical emergencies to provide safe dental care. Simulation training is available with simulators such as advanced life support manikins and robot patients. However, the purchase and development costs of these simulators are high. We have developed a simulation training course on medical emergencies using an inexpensive software application. The purpose of this study was to evaluate the educational effectiveness of this course. MATERIALS AND METHODS: Fifty-one dental providers participated in this study from December 2014 to March 2015. Medical simulation software was used to simulate a patient's vital signs. We evaluated participants' ability to diagnose and treat vasovagal syncope or anaphylaxis with an evaluation sheet and conducted a questionnaire before and after the scenario-based simulation training. RESULTS: The median evaluation sheet score for vasovagal syncope increased significantly from 7/9 before to 9/9 after simulation training. The median score for anaphylaxis also increased significantly from 8/12 to 12/12 (P < .01). For the item "I can treat vasovagal syncope/anaphylaxis adequately," the percentage responding "Strongly agree" or "Agree" increased from 14% to 56% for vasovagal syncope and from 6% to 42% for anaphylaxis with simulation training. CONCLUSIONS: This simulation course improved participants' ability to diagnose and treat medical emergencies and improved their confidence. This course can be offered inexpensively using a software application.

The Value of Tilt Testing and Autonomic Nervous System Assessment.

Tilt testing for the investigation of syncope was introduced in 1986. Since then, it has propagated worldwide as a routine test to determine the cause of transient loss of consciousness when that event has not been diagnosed by history, including that of a witness, physical examination, supine and erect blood pressures, and 12-lead electrocardiogram. Tilt testing allows reproduction of syncope with monitoring of physiologic parameters including electrocardiogram, beat-to-beat blood pressure, electroencephalogram, and middle cerebral artery blood-flow velocity. As a result, much has been learned about syncope.

Implantable rhythm devices in the management of vasovagal syncope.

The ECG registration during syncope allows physicians either to confirm or exclude an arrhythmia as the mechanism of syncope. Implantable loop recorders have an over-writeable memory buffer that continuously records and deletes the patient's ECG for up to three years. Many studies have analyzed the utility of implantable loop recorders in recurrent unexplained or high risk syncope. These studies suggest that early use of the ILR provides more and earlier diagnoses and could help in selecting patients with vasovagal syncope and prolonged asystolic pauses who might benefit from pacemaker therapy. However many questions remain, including its performance in the community by physicians with a range of experience in diagnosing syncope. Furthermore there is no evidence that the use of the ILR changes outcome. Numerous attempts have been made to determine whether patients with predominantly cardioinhibitory syncope benefit from permanent pacemakers, especially if symptoms are frequent and debilitating. While the first open label trials of pacemakers in the treatment of vasovagal syncope showed promising results, this effect has not been confirmed by blinded randomized clinical trials. More recent data seem to suggest that patients over 40years with severe asystolic vasovagal syncope might benefit from permanent pacemakers.

Assessment of therapeutic biomarkers in the treatment of children with postural tachycardia syndrome and vasovagal syncope.

BACKGROUND: Postural tachycardia syndrome and vasovagal syncope are common causes of orthostatic intolerance in children. The supplementation with water, or salt, or midodrine, or ß-blocker was applied to children with postural tachycardia syndrome or vasovagal syncope. However, the efficacy of such medication varied and was not satisfied. This review aimed to summarise the current biomarkers in the treatment of the diseases. DATA SOURCES: Studies were collected from online electronic databases, including OVID Medline, PubMed, ISI Web of Science, and associated references. The main areas assessed in the included studies were clinical improvement, the cure rate, and the individualised treatment for postural tachycardia syndrome and vasovagal syncope in children. RESULTS: Haemodynamic change during head-up tilt test, and detection of 24-hour urinary sodium excretion, flow-mediated vasodilation, erythrocytic H2S, and plasma pro-adrenomedullin as biological markers were the new ways that were inexpensive, non-invasive, and easy to test for finding those who would be suitable for a specific drug and treatment. CONCLUSION: With the help of biomarkers, the therapeutic efficacy was greatly increased for children with postural tachycardia syndrome and vasovagal syncope.

Assessment of the vasodepressor reflex in carotid sinus syndrome.

BACKGROUND: Assessment of the vasodepressor reflex in carotid sinus syndrome is influenced by the method of execution of the carotid sinus massage and the coexistence of the cardioinhibitory reflex. METHODS AND RESULTS: Carotid sinus massage reproduced spontaneous symptoms in 164 patients in the presence of hypotension or bradycardia (method of symptoms). When an asystolic pause was induced, the vasodepressor reflex was reassessed after suppression of the asystolic reflex by means of 0.02 mg/kg IV atropine. An isolated vasodepressor form was found in 32 (20%) patients, who had lowest systolic blood pressure (SBP) of 65±15 mm Hg. Of these, only 21 (66%) patients had an SBP fall ≥50 mm Hg, which is the universally accepted cut-off value for the diagnosis of the vasodepressor form. Conversely, a lowest SBP value of ≤85 mm Hg (corresponding to the fifth percentile) detected 97% of vasodepressor patients, but was also present in 84% of the 132 patients with an asystolic reflex. These latter patients had both asystole ≥3 s (mean 7.6±2.2 s) and SBP fall to 63±22 mm Hg: in 46 (28%) patients, symptoms persisted after atropine (mixed form), in the remaining 86 (52%) patients, symptoms did not (cardioinhibitory form) persist. CONCLUSIONS: The current definition of ≥50 mm Hg SBP fall failed to identify one third of patients with isolated vasodepressor form. A cut-off value of symptomatic SBP of ≤85 mm Hg seems more appropriate, but it is unable to identify cardioinhibitory forms. In asystolic forms, atropine testing is able to distinguish a cardioinhibitory form from a mixed form.

Update on the role of pacemaker therapy in vasovagal syncope and carotid sinus syndrome.

Vasovagal syncope (VVS) and carotid sinus syndrome (CSS) are related, neurally mediated disorders with different clinical features and treatment implications. Pacemaker intervention studies in both syndromes are hampered by a dearth of randomized, controlled (particularly with placebo) studies, unfortunate premature termination of studies, and variation in both the clinical presentation and cardiovascular profile of patients enrolled. Given this relatively limited evidence base, pacing therapy in VVS should be reserved for older sufferers with relatively frequent symptoms and spontaneous asystole documented during real-life monitoring. The long term course of patients paced for vasovagal syncope needs clarification, both in terms of symptom and device-related burden, while a comprehensive health economic evaluation of the costs and benefits of such an invasive approach for this usually benign condition is essential. It will also be important to determine the efficacy of closed loop stimulation pacing in an adequately powered study, including a comparison with standard pacing. Pacing should be considered in those with unexplained syncope with reproduction of symptoms during a cardio-inhibitory or mixed response to carotid sinus massage (asystole >3 s), though the evidence base for this recommendation is firmly in the consensus rather than pragmatic randomized controlled trial camp. Patients presenting with unexplained falls and drop attacks, particularly where injuries are prominent and where patients cannot give a clear account of their fall ("I just ended up on the floor, didn't slip or trip"), should also be considered for pacing. Pacing is not recommended for the vasodepressor sub-type of CSS.

[Assessment of vasovagal origin of syncope based on history features].

Study aim was to elaborate questionnaire for diagnostics of vasovagal syncope (VVS) based on data of anamnesis. We examined 182 patients (mean age 37.1+/-14.3 years, 78 men, 104 women). Initial examination included anamnesis, physical examination, electrocardiography at rest, measurement of blood pressure in orthostasis. Each patient was asked 82 questions describing duration of symptoms, characteristics of episodes of loss of consciousness, symptoms of prodromal period before loss on consciousness and in the period of recovery. As a standard method of VVS diagnostics of we used tilt test (TT) according to Westminster or Italian protocols. Using methods of statistical analysis we created questionnaire for diagnostics of VVS. Tilt-positive group comprised 108 patients (age 35.9+/-14.6 years, 45% men), tilt-negative group comprised 74 patients (age 36.1+/-14.3 years, 39% men). Of 82 testing questions 8 had probability ratio (PR) >1 and were significant predictors (<0.05) of positive TT. Seven questions had <1 and were significant predictors (<0.05) of negative TT. These questions were included into logistical regression analysis. The final variant of the questionnaire comprises 15 vasovagal origin questions. Total score necessary for diagnosis of VVS is more or equal 1. Sensitivity of questionnaire for prediction of positive result of TT was 95%, specificity - 57%. This allows to using it as a screening test for selection of further method of investigation in patients with episodes of loss of consciousness.

Epidemiology and economic impact of cardiac syncope in western countries.

This article updates our current understanding of the epidemiology and economic impact of syncope in western countries. Unfortunately, both of these aspects of syncope are inadequately understood; in part the problem is due to the difficulty in public health data separating 'true syncope' from conditions that cause other forms of transient loss of consciousness. However, in certain respects, the epidemiology of syncope is becoming clearer. Similarly, we have come to understand that the economic impact of syncope is substantial and is much larger than is necessary, primarily because management, especially excessive hospitalization, often remains suboptimal.

Assessment of systolic ejection time as a hemodynamic marker of incipient bradycardic vasovagal syncope. A pilot study.

BACKGROUND: Detection of markers of incipient syncope in patients with vasovagal syncope (VVS), without prodromal symptom, is still an open issue. The aim of this study was to assess the behavior of heart rate (HR) and ejection time, expressed as the percentage of the corresponding cardiac cycle (ET%), in patients with bradycardic VVS with a view to providing an alarm before the event. METHODS: In 33 patients with syncope and positive tilt testing and in 33 control patients, we collected beat-to-beat data on HR, ET%, stroke volume (SV), and blood pressure (BP). The trends of HR and ET% were analyzed. A set of combined changes of HR and ET% were tested in order to select the most appropriate algorithm for detecting the incipient syncope within the 3 minutes preceding the event. RESULTS: In patients with positive tilt testing, BP significantly decreased at 3 minutes before and at the time of syncope (P < 0.0001). HR slowly rose at 3 minutes before syncope and then suddenly decreased at the time of syncope (P < 0.0001). The correlation between SV and ET% was r = 0.79 (P < 0.0001). SV and ET% significantly decreased throughout tilt testing (P < 0.0001). The selected setting for the algorithm provided sensitivity of 97% and specificity of 73%. The theoretical alarm was generated at least 9 and 5 seconds before syncope, respectively, in 76% and 85% of the subjects. CONCLUSION: The combined trends in HR and ET% may provide a marker of incipient bradycardic VVS in the majority of patients.

The changing face of orthostatic and neurocardiogenic syncope with age.

AIM: Reports of the outcomes of syncope assessment across a broad spectrum of ages in a single population are scarce. It is our objective to chart the varying prevalence of orthostatic and neurocardiogenic syncope (NCS) as a patient ages. METHODS: This was a retrospective study. All consecutive patients referred to a tertiary referral syncope unit over a decade were included. Patients were referred with recurrent falls or orthostatic intolerance. Tilt tests and carotid sinus massage (CSM) were performed in accordance with best practice guidelines. RESULTS: A total of 3002 patients were included (1451 short tilt, 127 active stand, 1042 CSM and 382 prolonged tilt). Ages ranged from 11 to 91 years with a median (IQR) of 75 (62-81) years. There were 1914 females; 1088 males. Orthostatic hypotension (OH) was the most commonly observed abnormality (test positivity of 60.3%). Those with OH had a median (IQR) age of 78 (71-83) years. Symptomatic patients were significantly younger than asymptomatic (P = 0.03). NCS demonstrated a bimodal age distribution. Of 194 patients with carotid sinus hypersensitivity, the median age (IQR) was 77 (68-82) years. Those with vasovagal syncope (n = 80) had a median (IQR) age of 30 (19-44) years. There were 57 patients with isolated postural orthostatic tachycardia syndrome. Of the total patients, 75% were female. They had a median (IQR) age of 23 (17-29) years. CONCLUSION: We have confirmed, in a single population, a changing pattern in the aetiology of syncope as a person ages. The burden of disease is greatest in the elderly.

Cost-effectiveness of diagnostic approaches to vasovagal syncope.

BACKGROUND: Syncope is a common clinical problem with multiple causes. Vasovagal syncope (VVS) is by far the most frequent cause of syncope in children and adolescents. The traditional diagnostic approach to VVS of children and adolescents is based on a series of tests to exclude all other causes, which is complex and time and medical resource consuming. Attempts have been made to develop a new cost-effective diagnostic approach to avoid these problems. This study aimed to compare the economic effectiveness and diagnostic value of the traditional diagnostic approach to VVS of children with a new diagnostic approach. METHODS: One hundred and eighteen children diagnosed as VVS were divided into two groups according to the different diagnostic approaches. The diagnostic value of the two diagnostic approaches was then analyzed. Meanwhile, the costs of hospitalization, diagnostic testing and hospital stay were determined. Data were evaluated by the cost-minimization analysis. RESULTS: The diagnostic value of the new diagnostic approach was similar to that of the traditional diagnostic approach (56.57% vs. 53.91%, P = 0.697). However, the cost of hospitalization per patient by the new diagnostic approach was (1507.08 ± 144.63) Yuan (RMB) which was less than that of the traditional diagnostic approach (2603.64 ± 208.19) Yuan. The costs of diagnostic tests per patient by the new diagnostic approach was (1256.04 ± 109.14) Yuan and by the traditional approach (2175.22 ± 153.32) Yuan. CONCLUSION: Compared to the traditional diagnostic approach to diagnose VVS in children and adolescents, the new diagnostic approach is of a good economic value, and it should be popularized in clinical practice.

Implantable loop recorders in the investigation of unexplained syncope: a state of the art review.

Since its introduction 15 years ago, the implantable loop recorder (ILR) has become the investigative tool of choice in recurrent unexplained syncope following negative initial investigations. This is based on very few randomised controlled clinical trials and modestly sized observational studies. Further controlled data are required to inform clinical practice with attention focused on empowering ILR-guided diagnosis, establishing the optimal timing of ILR use in syncope and embracing new technological advancements.

Recent history of vasovagal syncope in a young, referral-based population is a stronger predictor of recurrent syncope than lifetime syncope burden.

INTRODUCTION: accurate selection of patients for vasovagal syncope studies requires strong risk stratification and knowledge of the natural history of syncope. We aimed to test the hypothesis that recent history of vasovagal syncope compared to distant history better predicts subsequent recurrence of syncope. METHODS AND RESULTS: in all, 208 subjects with a positive tilt test and ≥ 3 lifetime syncope spells were followed for 1 year. Syncope episodes in the preceding year and total historical spells were compared for their ability to predict a syncope recurrence using the criteria of optimal statistical significance, best linear separation of risk populations, and impact on power calculations. The number of vasovagal syncope spells in the preceding year better predicted syncope recurrence when compared to total number of historical spells (likelihood ratio statistic 28.4, P < 0.0001; versus 20.4, P = 0.001), and showed a substantial effect as the number of syncope events increased. For example, syncope recurred in 22% of those with <2 spells in the previous year compared to 69% in those with >6 spells. A history of no syncope compared to any syncope in the preceding year was associated with a 1-year probability of 7% versus 46% for syncope recurrence. A study designed to detect a 50% decrease in syncope recurrence at P = 0.05 with 80% power would require 159 patients with at least 3 lifetime spells, and only 108 patients with at least 3 spells in the previous year. CONCLUSIONS: the number of syncope events in the year preceding clinical evaluation is the best predictor of syncope recurrence.

What is the optimal duration of tilt testing for the assessment of patients with suspected postural tachycardia syndrome?

AIMS: The aim of this study is to define the optimal duration of tilt testing for the assessment of patients with suspected postural tachycardia syndrome (POTS). METHODS AND RESULTS: This was a case-control study. Cases were identified retrospectively from a database of patients referred with orthostatic intolerance (OI). All met the diagnostic criteria for POTS. Controls were enrolled prospectively. All subjects underwent tilting to 70 degrees for 40 min if tolerated. Continuous monitoring was provided by a Finometer. Analysis of responses to tilting was performed on 28 cases and 28 controls. The mean age in the case group was 23.6 and in the control group was 26.2. The majority was female in both groups (cases = 4F:3M, controls = 2F:1M). All cases met the criteria for POTS within 7 min of orthostasis. No controls demonstrated a sustained tachycardia. The prevalence of vasovagal syncope (VVS) was 36% in cases vs. 7% in controls (P = 0.02) and 25% in the remaining patients (n = 233) on the OI database (P = 0.259). CONCLUSION: A 10 min tilt will diagnose POTS in the majority of patients. It will not, however, be sufficient to identify the overlap that exists between POTS and VVS. The optimal duration of tilt testing in patients suspected of POTS is 40 min.

Assessment of cardiovascular autonomic function.

Autonomic assessment has played an important role in elucidating the role of the autonomic nervous system in diverse clinical and research settings. The techniques most widely used in the clinical setting entail the measurement of an end-organ response to a physiological provocation. The non-invasive measures of cardiovascular parasympathetic function involve the analysis of heart rate variability while the measures of cardiovascular sympathetic function assess the blood pressure response to physiological stimuli. Prolonged tilt-table testing, with or without pharmacological provocation, has become an important tool in the investigation of a predisposition to neurally mediated (vasovagal) syncope. Frequency domain analyses of heart rate and blood pressure variability, microneurography, occlusion plethysmography, laser Doppler imaging and flowmetry, and cardiac sympathetic imaging are currently research tools but may find a place in the clinical assessment of autonomic function in the future.

[Orthostatic intolerance--prevalence, diagnostic management and its significance for occupational medicine]. / Orthostatische Intoleranz--Prävalenz, Diagnostik und die Bedeutung für die Arbeitsmedizin.

OBJECTIVE: Orthostatic intolerance (OI) is a syndrome which is characterised by headache, concentration difficulties, palpitation of the heart, dizziness associated with postural tachycardia and plasma norepinephrine concentrations that are disportionately high in upright posture. OI hitherto can only be diagnosed by a tilt table examination with high expenditure. In this paper we examine the reliability and validity of a questionnaire as a screening instrument for OI. METHODS: We studied 138 young males (mean age 21.6 years) from the military service. After a medical check and filling in the questionnaire, the participants underwent a tilt table test. The questionnaire consisted of 10 items registering presence and frequency of typical OI-symptoms. RESULTS: 104 probands showed a normal tilt table test. OI was diagnosed in 14 probands, orthostatic hypotension (OH) in 6 and postural orthostatic tachycardia syndrome (POTS) in 14. The participants with OI scored significantly higher in the questionnaire than the normal subjects: The mean score of the OI group was 22.6, the normal participants had a mean score of 3.9. Participants with POTS had a mean score of 13.5 and subjects with OH had a mean score of 17.0. CONCLUSIONS: We were able to establish a short questionnaire as a reliable and valid screening instrument for OI. Usage of this questionnaire can simplify enormously the diagnostic management of patients with suspected OI.