Vasovagal Syncope in the Older Patient

Global prevalence of vasovagal syncope: A systematic review and meta-analysis

Background

Today, vasovagal syncope is a common problem that has become a significant health and social challenge. The present study investigated the global prevalence of vasovagal syncope using a systematic review and meta-analysis.Methods: In this systematic review and meta-analysis study, the global prevalence of vasovagal syncope using the keywords Prevalence, Epidemiology, Vasovagal syncope, and Reflex syncope in PubMed, WoS, Scopus, ScienceDirect databases, and Google scholar search engine without time limit until July 20, 2022, was extracted and transferred to the information management software (EndNote). Then the repeated studies were excluded, and researchers evaluated the remaining studies during three stages (i.e., screening, eligibility, and qualitative assessment). The heterogeneity of studies was investigated using the I2 index, and the analysis of eligible studies was performed using the random effects model.

Results

In the review of 12 studies with a sample size of 36,156 people, the global prevalence of vasovagal syncope was reported as 16.4 (95%CI: 6-37.5), and the study of publication bias in the studies through the Egger test shows the absence of publication bias in the studies.

Conclusion

The prevalence reported in the studies shows a high prevalence of vasovagal syncope, which requires serious intervention and preventive, diagnostic, and therapeutic measures. It is necessary for health policymakers to take effective measures in this field.

Predictors of pacemaker requirement in patients receiving implantable loop recorders for unexplained syncope: A systematic review and meta-analysis

BACKGROUND

Implantable loop recorders (ILRs) are increasingly used to evaluate patients with unexplained syncope. Identification of all predictors of bradycardic syncope and consequent permanent pacemaker (PPM) insertion is of substantial clinical interest as patients in the highest risk category may benefit from upfront pacemaker insertion.

OBJECTIVE

We performed a systematic review and meta-analysis to identify risk predictors for PPM insertion in ILR recipients with unexplained syncope.

METHODS

An electronic database search (MEDLINE, Embase, Scopus, Cochrane) was performed in June 2023. Studies evaluating ILR recipients with unexplained syncope and recording risk factors for eventual PPM insertion were included. A random effects model was used to calculate the pooled odds ratio (OR) for clinical and electrocardiographic characteristics with respect to future PPM requirement.

RESULTS

Eight studies evaluating 1007 ILR recipients were included; 268 patients (26.6%) underwent PPM insertion during study follow-up. PPM recipients were older (mean age, 70.2 ± 15.4 years vs 61.6 ± 19.7 years; P < .001). PR prolongation on baseline electrocardiography was a significant predictor of PPM requirement (pooled OR, 2.91; 95% confidence interval, 1.63-5.20). The presence of distal conduction system disease, encompassing any bundle branch or fascicular block, yielded a pooled OR of 2.88 for PPM insertion (95% confidence interval, 1.53-5.41). Injurious syncope and lack of syncopal prodrome were not significant predictors of PPM insertion. Sinus node dysfunction accounted for 62% of PPM insertions, whereas atrioventricular block accounted for 26%.

CONCLUSION

Approximately one-quarter of ILR recipients for unexplained syncope require eventual PPM insertion. Advancing age, PR prolongation, and distal conduction disease are the strongest predictors for PPM requirement.

Definitive aetiology of unexplained syncope after cardiovascular autonomic tests in a tertiary syncope unit

AIMS

Syncope is a common condition with many possible causes, ranging from benign to life-threatening aetiologies. Establishing a diagnosis can be difficult, and specialized syncope units, using cardiovascular autonomic tests (CATs), including a head-up tilt test, can increase the diagnostic yield. However, up to one-fifth of examined patients have inconclusive CAT results. The aim of the present study was to investigate the predictive value of history, and clinical findings for unexplained syncope after CAT and characterize the group with negative results.

METHODS AND RESULTS

Consecutive syncope patients [n = 2663, 61% women, median age 52 (32-69) years] were evaluated and CAT explained aetiology of syncope in 79% of cases, whereas 21% remained unexplained. Predictors of negative CAT were older age at first syncope (+8% higher odds per 10-year increment, P = 0.042), higher supine heart rate (HR; +12% per 10 b.p.m.; P = 0.003), absence of prodromes (+48%; P < 0.001), hypertension (+45%; P = 0.003), diabetes (+82%; P < 0.001), heart failure (+98%; P = 0.014), and coronary artery disease (+51%; P = 0.027). Compared with vasovagal syncope, patients with negative CAT were older, reported more often the absence of prodromes, and had a higher burden of cardiovascular comorbidities.

CONCLUSION

A cardiovascular autonomic test established the cause of syncope in 79% of patients evaluated in a syncope unit. Syncope without prodromes and cardiovascular comorbidities were significant predictors of failure to reveal an aetiology from assessment by CAT. These are known risk factors for cardiac syncope and patients with inconclusive CAT warrant further investigation.

The effect of intravenous granisetron on prophylactic ephedrine for preventing hypotension after general anaesthesia induction in elderly patients: a randomized controlled trial

Serotonin 3 receptor antagonists, a commonly used drug for preventing postoperative nausea and vomiting, have recently been reported to decrease the incidence of hypotension and the need for vasoactive drugs after spinal anaesthesia in obstetric surgery. However, it remains unknown whether they could also prevent hypotension after induction of general anaesthesia. In the current study, we aimed to investigate the effect of intravenous granisetron on prophylactic ephedrine for preventing hypotension after general anaesthesia induction in elderly patients. Sixty elderly patients were randomly assigned to receive granisetron or saline control 30 min before induction of general anaesthesia. The first patient in each group received a prophylactic dose of ephedrine (0.15 mg kg^-1) to prevent hypotension. The prophylactic dose for each patient was increased or decreased by 0.05 mg/kg based on the efficacy results of the previous patient. The up-down sequential allocation analysis and probit regression was used to calculate the effective dose for 50% of patients (ED50) with prophylactic ephedrine. In the up-down sequential allocation analysis, the ED50 of ephedrine was significantly lower in group granisetron (0.08 mg kg^-1 [95% CI, 0.06-0.11 mg kg^-1]) when compared with group control (0.14 mg kg^-1 [95% CI, 0.13-0.16 mg kg^-1]) (P < 0.001). The conclusion was further supported by probit regression analysis (0.09 mg kg^-1 [95% CI, 0.05-0.12 mg kg^-1] in group granisetron and 0.14 mg kg^-1 [95% CI, 0.12-0.16 mg kg^-1] in group control). Intravenous granisetron reduced the requirement of prophylactic ephedrine in preventing hypotension after general anaesthesia induction in elderly patients.

The Autonomic Coumel Triangle: A New Way to Define the Fascinating Relationship between Atrial Fibrillation and the Autonomic Nervous System

Arrhythmogenic substrate, modulating factors, and triggering factors (the so-called Coumel's triangle concept) play a primary role in atrial fibrillation (AF) pathophysiology. Several years have elapsed since Coumel and co-workers advanced the concept of the relevance of autonomic nervous system (ANS) influences on atrial cells' electrophysiological characteristics. The ANS is not only associated with cardiac rhythm regulation but also exerts an important role in the triggering and maintenance of atrial fibrillation. This review aims to describe in detail the autonomic mechanisms involved in the pathophysiology of atrial fibrillation (AF), starting from the hypothesis of an "Autonomic Coumel Triangle" that stems from the condition of the fundamental role played by the ANS in all phases of the pathophysiology of AF. In this article, we provide updated information on the biomolecular mechanisms of the ANS role in Coumel's triangle, with the molecular pathways of cardiac autonomic neurotransmission, both adrenergic and cholinergic, and the interplay between the ANS and cardiomyocytes' action potential. The heterogeneity of the clinical spectrum of the ANS and AF, with the ANS playing a relevant role in situations that may promote the initiation and maintenance of AF, is highlighted. We also report on drug, biological, and gene therapy as well as interventional therapy. On the basis of the evidence reviewed, we propose that one should speak of an "Autonomic Coumel's Triangle" instead of simply "Coumel's Triangle".

Genetic variants associated with syncope implicate neural and autonomic processes

AIMS

Syncope is a common and clinically challenging condition. In this study, the genetics of syncope were investigated to seek knowledge about its pathophysiology and prognostic implications.

METHODS AND RESULTS

This genome-wide association meta-analysis included 56 071 syncope cases and 890 790 controls from deCODE genetics (Iceland), UK Biobank (United Kingdom), and Copenhagen Hospital Biobank Cardiovascular Study/Danish Blood Donor Study (Denmark), with a follow-up assessment of variants in 22 412 cases and 286 003 controls from Intermountain (Utah, USA) and FinnGen (Finland). The study yielded 18 independent syncope variants, 17 of which were novel. One of the variants, p.Ser140Thr in PTPRN2, affected syncope only when maternally inherited. Another variant associated with a vasovagal reaction during blood donation and five others with heart rate and/or blood pressure regulation, with variable directions of effects. None of the 18 associations could be attributed to cardiovascular or other disorders. Annotation with regard to regulatory elements indicated that the syncope variants were preferentially located in neural-specific regulatory regions. Mendelian randomization analysis supported a causal effect of coronary artery disease on syncope. A polygenic score (PGS) for syncope captured genetic correlation with cardiovascular disorders, diabetes, depression, and shortened lifespan. However, a score based solely on the 18 syncope variants performed similarly to the PGS in detecting syncope risk but did not associate with other disorders.

CONCLUSION

The results demonstrate that syncope has a distinct genetic architecture that implicates neural regulatory processes and a complex relationship with heart rate and blood pressure regulation. A shared genetic background with poor cardiovascular health was observed, supporting the importance of a thorough assessment of individuals presenting with syncope.

OUP accepted manuscript

Aims

Methods and results

Conclusion

Syncope and the aging patient: Navigating the challenges

Syncope in the elderly patient is a common presentation and the most common causes are usually non-cardiac. Older adults however are more challenging dilemmas as their presentation is complicated by co-morbidities, mainly cardiovascular and neurodegenerative disorders. Frailty and cognitive impairment add to the ambiguity of the presentation, and polypharmacy is often a major modifiable contributing factor. Vasovagal syncope is a common presentation throughout life even as we age. It has a favorable prognosis and conservative management usually suffices. Vasovagal syncope in this population may be misdiagnosed as accidental falls and is frequently associated with injury, as is carotid sinus syndrome. The initial approach to these patients entails a detailed history and physical examination including a comprehensive medication history, orthostatic vital signs, and a 12-lead electrocardiogram. Further cardiac and neuroimaging rarely helps, unless directed by specific clinical findings. Head-up tilt testing and carotid sinus massage retain their diagnostic accuracy and safety in the elderly, and implantable loop recorders provide important information in many elderly patients with unexplained falls and syncope. The starting point in management of this population with non-cardiac syncope is attempting to withdraw unnecessary vasoactive and psychotropic medications. Non-pharmacologic and pharmacologic therapy for syncope in the elderly has limited efficacy and safety concerns. In selected patients, pacemaker therapy might offer symptomatic relief despite lack of efficacy when vasodepression is prominent. An approach focused on primary care with targeted specialist referral seems a safe and effective strategy.

Unexplained falls in the elderly

Falls are a geriatric syndrome affecting mortality, morbidity, and institutionalization. Falls are also the leading cause of unintentional injury and a common emergency department presentation. Physical and psychological issues may develop after falling, leading to increase in dependency and disability and their relative costs. The pathogenesis of falls is multi-factorial, being indeed the result of the interaction between increased individual susceptibility, high risk activities and environmental hazards. The patient should be evaluated for gait, standing balance, mobility, muscle weakness, cognitive status, osteoporosis risk, sensorial impairment, urinary incontinence, functional status, and for possible residential environmental hazards. It is also mandatory to obtain a full report of the circumstances and a careful therapeutic recognition. However not all falls are explainable. Indeed, retrograde amnesia and the frequent absence of a witness complicate history collection of falls in older adults. In this case, "the management of unexplained falls should be the same as that for unexplained syncope" as stated by the latest version of the European Society of Cardiology guidelines on syncope. In this context, the investigation of the cardiovascular autonomic nervous system and the use of implantable loop recorder have an increasing role. The present paper addresses the diagnostic approach to falls in older adults through a comprehensive multifactorial risk assessment and examines evidence and gaps on fall prevention strategies.

Vasovagal syncope related to pain procedures in a pain clinic at a tertiary Lebanese hospital between 2016 and 2019

Objectives

Our study focuses on evaluating the factors associated with vasovagal syncope (VVS) when having a pain procedure at the pain clinic as well as showing variation in vital signs associated with fainting across different periods of the procedure (before, during and after).A retrospective case control study was conducted in a university hospital in Lebanon (CHU-NDS) on adult Lebanese patients with data taken from the archives covering a 4 year period (2016–2019).

Results

The multivariable analysis showed that a higher systolic blood pressure per-procedure was significantly associated with lower odds of having vasovagal syncope. An adequate dose of a vasopressor like ephedrine can be used to prevent a vasovagal event from happening. In our study the blood pressure component was more significant than the heart rate component which stayed in the normal range limit in the three different periods of procedure. Cases having a pain procedure for the first time represent 59.6% of the occurrence of VVS. Vasovagal syncope is a complication that can be prevented in high risk patients. Our study suggests taking preventive measures for VVS for patients with first time infiltration status especially if appearing in an anxious state.

Are women really more affected by vasovagal syncope than men?

It is commonly reported that vasovagal syncope (VVS) is more frequent in women. Presently, this issue has never been investigated. The purpose of this review was to evaluate, through an extensive review of the literature, whether women are really more affected by VVS than men. The gender distribution was investigated in individuals with classical and nonclassical VVS. The database PubMed was searched using the terms 'syncope', 'vasovagal syncope', 'neurally mediated syncope' and 'tilt testing'. Twelve studies dealing with classical and 75 with nonclassical VVS were eligible. In the individuals with classical (N = 1861) and nonclassical VVS (N = 9696), a trend towards a greater percentage of women emerged (P = 0.14 and 0.07, respectively). In the total population with VVS (N = 11 557), the percentage of women was significantly higher than that of men (58 versus 42%, P = 0.03). Most of the individuals were young or middle-aged. In 84% of the studies, the percentage of women was greater than that of men. A separate analysis was carried out in older VVS patients (≥60 years) and only two studies were eligible to be evaluated. Considering that almost all the studies were carried out in the western nations, where the number of men and women is almost superimposable until the age of 65 years and a bias by gender has never been reported in the management of VVS, these data strongly suggest that young and middle-aged women are more affected by VVS than their male counterparts. At present, data are too scant to draw a definitive conclusion in older VVS patients.

Serum Asymmetric Dimethylarginine Levels in Patients with Vasovagal Syncope

Background and Objectives: Vasovagal syncope (VVS) is the most common cause of syncope and has multiple pathophysiological mechanisms. Asymmetric dimethylarginine (ADMA) is the major inhibitor of nitric oxide (NO). In this study, we aimed to investigate the relationship between plasma ADMA levels and syncope during the head-up tilt (HUT) test. Materials and Methods: Overall, 97 patients were included in this study. They were above 18 years of age and were admitted to our clinic with the complaint of at least one episode of syncope consistent with VVS. The HUT test was performed in all patients. Patients were divided into the following two groups based on the HUT test results: group 1 included 57 patients with a positive HUT test and group 2 included 35 patients with a negative HUT test. Blood samples were taken before and immediately after the HUT test to measure ADMA levels. Results: No significant intergroup differences were observed concerning gender and age (female gender 68% vs 60%; mean age 24.85 ± 4.01 vs 25.62 ± 3.54 years, respectively, for groups 1 and 2). ADMA values were similar between groups 1 and 2 before the HUT test [ADMA of 958 (544–1418) vs 951 (519–1269); p = 0.794]. In the negative HUT group, no significant differences were observed in ADMA levels before and after the HUT test [ADMA of 951 (519–1269) vs 951 (519–1566); p = 0.764]. However, in the positive HUT group, ADMA levels were significantly decreased following the HUT test [pretest ADMA of 958 (544–1418) vs post-test ADMA of 115 (67–198); p < 0.001]. Conclusion: ADMA levels significantly decreased after the HUT test in patients with VVS.

Sick Sinus Syndrome

The sick sinus syndrome includes symptoms and signs related to sinus node dysfunction. This can be caused by intrinsic abnormal impulse formation and/or propagation from the sinus node or, in some cases, by extrinsic reversible causes. Careful evaluation of symptoms and of the electrocardiogram is of crucial importance, because diagnosis is mainly based on these 2 elements. In some cases, the pathophysiologic mechanism that induces sinus node dysfunction also favors the onset of atrial arrhythmias, which results in a more complex clinical condition, known as "bradycardia-tachycardia syndrome."

Renal nerve stimulation for treatment of neurocardiogenic syncope: a review from perspective of commercialization potential

A strong evidence of outcomes for vasovagal syncope is not easily identified. It would seem reasonable that the proposed Mayo Clinic technology would be reserved for cases with severe recurrent or refractory syncope. However, recurrence levels are relatively low, and while some predictive methods have been proposed, recurrence is also influenced by the interaction that occurs during screening and examinations, i.e. recurrence diminishes once an initial diagnosis has been made. Finally, a key factor in being able to identify suitable patients relates to understanding the relative significance of the vasodepression and cardioinhibitory components-the therapy is best suited to patients that have a significant level of both components. It is probably not needed in patients with mainly cardioinhibitory involvement-data from ISSUE 2 and ISSUE 3 studies suggest that this is a relatively large proportion, particularly with asystolic involvement. The challenge remains in having suitable screening tests to identify the best patients. Tilt table testing has questions concerning its ability to replicate clinical syncope-implantable loop recorders (ILRs) may provide more accurate data but their usage is not yet widely accepted given the costs and invasive nature of the monitor.

The Current Indication for Pacemaker in Patients with Cardioinhibitory Vasovagal Syncope

The most frequent cause of syncope is vasovagal reflex. It is associated with worse quality of life, depression, fatigue and physical injury. Recurrence of vasovagal syncope is an aggravating, reaching the rate of 69%. Initial step and pharmacological treatment may not work, especially in patients with recurrent syncope without prodrome. These patients can present cardioinhibitory response with asystole. Studies were designed to analyses the effectiveness of pacemaker for prevention of syncope. In this review, nonrandomized clinical trials, open-label randomized, double-blind randomized, placebo-controlled, and studies based on tilt test or Implantable Loop Recorder findings will be discussed.

Managing Syncope in the Elderly: The Not So Simple Faint in Aging Patients

Providing care to the elderly patient with syncope poses problems that are unusual in their complexity. The differential diagnosis is broad, and sorting through it is made more difficult by the relative lack of symptoms surrounding the faint. Indeed, distinguishing faints from falls is often problematic. Many elderly patients are frail and are at risk of trauma if they should have an unprotected faint or fall to the ground. However, not all elderly patients are frail, and definitions of frailty vary. Providing accurate, effective, and appropriate care for the frail elderly patient who faints may require a multidisciplinary approach.

Home Orthostatic Training in Elderly Patients with Vasovagal Syncope - A Prospective Randomised Controlled Trial

Aim: The aim of this study was to assess the effect of home orthostatic training (HOT) on autonomic reflexes in elderly patients with vasovagal syncope (VVS). Methods: Design and Setting: A single-blind randomised control trial was conducted at Eastbourne District General Hospital, East Sussex NHS Trust. Patients: Individuals with recurrent syncope underwent tilt-table testing between August 2007 and October 2009.Those with at least two syncopal episodes and tilt-test proven VVS were recruited. Participants were divided into those aged >65 years (O65) and those aged <65 years (U65). Interventions: Patients in the O65 group were randomised 1:1 to receive active HOT (O65+) or sham HOT (O65-). The U65 group received active HOT. Participants performed HOT/sham HOT and recorded their training and symptoms. Patients had a repeat tilt test at 3 months. Outcome Measures: Time to syncope at repeat tilt-table testing, low-frequency heart rate variability (LF-HRV), high-frequency heart rate variability (HF-HRV), mean upslope baroreflex sensitivity (BRS) and mean downslope BRS were assessed. Results: A total of 106 patients with recurrent syncope underwent tilt-table testing. Of these, 45 consecutive patients (30 in the O65 group and 15 in the U65 group) were recruited. Two, one and three patients withdrew or were lost-to-follow-up in the O65+, O65-, and U65 groups, respectively. Symptomatic benefit occurred in four (31 %) of the O65+, four (29 %) of the O65-, and six (50 %) of the U65. None of the autonomic measures changed significantly in any group. No difference was seen with HF-HRV, LF-HRV mean upslope BRS and mean downslope BRS. Fifty per-cent of the O65+ group stopped training because of back pain. Time constraint (25 %) was the most common reason for cessation in the U65 group. Conclusions: Despite good tilt training compliance, no improvement in autonomic measures in any group was shown. The most common reason for cessation of training was back pain in the elderly groups. This study does not support the use of HOT in elderly patients.

Effect of ondansetron on prevention of post-induction hypotension in elderly patients undergoing general anesthesia: A randomized, double-blind placebo-controlled clinical trial

Background:

Elderly patients are susceptible to post-induction hypotension. Volume loading and vasopressors for prevention of hypotension in elderly patients may increase perioperative cardiovascular risks. Ondansetron by blocking Bezold–Jarisch reflex (BJR) through inhibition of serotonin receptors has been effective in the prevention of post-spinal hypotension, and bradycardia. Bradycardia frequently accompanies post-induction hypotension in elderly patients, which signifies a possible preventing role for ondansetron. No previous study has evaluated the prophylactic effects of ondansetron for the prevention of post-induction hypotension.

Materials and Methods:

In this randomized placebo-controlled clinical trial, ondansetron 4 mg was given intravenously to 65 elderly patients, 20 min before induction of general anesthesia, and the rate of post-induction hypotension defined as 25% or more reduction in mean arterial blood pressure, compared with a placebo groups.

Results:

A total of 114 patients completed the study (58 in ondansetron and 56 in the placebo group). Proportions of post-induction hypotension were 9 (16%) and 25 (45%) in ondansetron and placebo groups, respectively, (P = 0.001). Forty-five patients (40%) developed bradycardia. Rates of bradycardia were not significantly different between two groups.

Conclusions:

The results of this study show the effectiveness of intravenous ondansetron for prevention of post-induction hypotension in elderly patients. The mechanism of this effect largely is unknown. Role of ondansetron for prevention of post-induction hypotension may not fully understandable by its interaction with BJR, as has been shown in post-spinal hypotension.

The different clinical presentations of vasovagal syncope

For some decades, after the introduction of the head-up tilt test into clinical practice, the clinical presentation of vasovagal syncope (VVS) has been classified as typical (or classical) and atypical (or non-classical). Some clinical features and recent data suggest that even unexplained falls and syncope during sleeping hours may be possible clinical presentations of VVS. In recent studies, tilt testing and carotid sinus massage by means of the 'method of symptoms' were performed in one group of patients with unexplained falls and in another group with unexplained syncope (presence of prodromal symptoms). Overall, tilt testing and carotid sinus massage displayed a high positivity rate in the group of patients with unexplained falls (about 60%), which was similar to that of the unexplained syncope group. These new data seem to indicate that some unexplained falls could be cases of atypical VVS/carotid sinus syncope with retrograde amnesia. Some clinical features suggest that syncope during sleeping hours is a form of VVS with a different clinical presentation: high prevalence of autonomic prodromes, of diurnal episodes of typical VVS and specific phobias, and of positive tilt testing with severe cardioinhibition.

Syncope: diagnosis and management

Syncope is defined as transient loss of consciousness due to global cerebral hypoperfusion. It is characterized by having a relatively rapid onset, brief duration with spontaneous and full recovery. The major challenge in the evaluation of patients with syncope is that most patients are asymptomatic at the time of their presentation. A thorough history and physical examination including orthostatic assessment are crucial for making the diagnosis. After initial evaluation, short-term risk assessment should be performed to determine the need for admission. If the short-term risk is high, inpatient evaluation is needed. If the short-term risk is low, outpatient evaluation is recommended. In patients with suspected cardiac syncope, monitoring is indicated until a diagnosis is made. In patients with suspected reflex syncope or orthostatic hypotension, outpatient evaluation with tilt-table testing is appropriate. Syncope units have been shown to improve the rate of diagnosis while reducing cost and thus are highly recommended.

The relationship between syncope, depression and anti-depressant use in older adults

BACKGROUND

syncope is a common problem which increases in older age groups. In syncope clinics, patients who are depressed have higher rates of unexplained syncope and higher rates of recurrent syncope.

OBJECTIVES

: we aim to examine the rates of depression in older patients reporting syncope and the effect of anti-depressants (ADs) on the rates of syncope.

DESIGN

: epidemiological, point-prevalence study.

SETTING AND PARTICIPANTS

: data came from the Irish Longitudinal Study on Ageing, which includes 8,175 adults aged 50 and older, living in the community in Ireland.

MEASUREMENTS

: the Centre for Epidemiological Studies Depression scale was used to assess levels of depression. Multinomial regression was used to analyse the data with a P-value of <0.05 determining significance.

RESULTS

: 7,993 participants aged 50 and older were included, and of these 349 reported at least one syncopal episode in the last year. Prevalence of syncope was 4.4%. After controlling for participant characteristics and general health, those with severe depression had a greater risk of single and multiple syncopal events (relative risk ratios [RRR]: 2.78 and 2.84, respectively, P < 0.050) and participants treated with tricyclic anti-depressants (TCAs) were also at greater risk for single and multiple syncopal episode in the last year (RRR: 2.31, P = 0.062; RRR: 2.95, P < 0.05).

CONCLUSIONS

: this study demonstrates an increased risk of syncope in patients with depression, with higher rates of syncope reported with increasing severity of depression. Treatment with TCAs increases both the risk and frequency of syncope in the community. Depression is a potentially modifiable risk factor for syncope but treatment options need to be tailored in the older patient population.

Repeated pre-syncope from increased inspired CO2 in a background of severe hypoxia

We describe a case of experimentally induced pre-syncope in a healthy young man when exposed to increased inspired CO2 in a background of hypoxia. Acute severe hypoxia (FIO2=0.10) was tolerated, but adding CO2 to the inspirate caused pre-syncope symptoms accompanied by hypotension and large reductions in both mean and diastolic middle cerebral artery velocity, while systolic flow velocity was maintained. The mismatch of cerebral perfusion pressure and vascular tone caused unique retrograde cerebral blood flow at the end of systole and a reduction in cerebral tissue oxygenation. We speculate that this occurrence of pre-syncope was due to hypoxia-induced inhibition of brain regions responsible for compensatory sympathetic activity to relative hypercapnia.

Syncope in the Elderly

A rapid change in ageing demographic is taking place worldwide such that healthcare professionals are increasingly treating old and very old patients. Syncope in the elderly is a challenging presentation that is under-recognised, particularly in the acute care setting. The reason for this is that presentation in the older person may be atypical: patients are less likely to have a prodrome, may have amnesia for loss of consciousness and events are frequently unwitnessed. The older patient thus may present with a fall rather than transient loss of consciousness. There is an increased susceptibility to syncope with advancing age attributed to age-related physiological impairments in heart rate and blood pressure, and alterations in cerebral blood flow. Multi-morbidity and polypharmacy in these complex patients increases susceptibility to syncope. Cardiac causes and more than one possible cause are also common. Syncope is a major cause of morbidity and mortality and is associated with enormous personal and wider health economic costs. In view of this, prompt assessment and early targeted intervention are recommended. The purpose of this article is to update the reader regarding the presentation and management of syncope in this rapidly changing demographic.

Head-up tilt testing for diagnosing vasovagal syncope: a meta-analysis

BACKGROUND

A systematic evaluation focused on sensitivity and specificity of head-up tilt testing (HUT) for diagnosing vasovagal syncope has not been previously performed. We conducted a meta-analysis of studies comparing HUT outcome between patients with syncope of unknown origin and control subjects without previous syncope.

METHODS

We searched Pubmed and Embase databases for all English-only articles concerning case-control studies estimating the diagnostic yield of HUT, and selected 55 articles, published before March 2012, including 4361 patients and 1791 controls. The influence of age, test duration, tilt angle, and nitroglycerine or isoproterenol stimulation on tilt testing outcome was analyzed.

RESULTS

Head-up tilt testing demonstrated to have a good overall ability to discriminate between symptomatic patients and asymptomatic controls with an area under the summary receiver-operating characteristics curve of 0.84 and an adjusted diagnostic odds ratio of 12.15 (p<0.001). A significant inverse relationship between sensitivity and specificity of tilt testing for each study was observed (p<0.001). At multivariate analysis, advancing age and a 60° tilt angle showed a significant effect in reducing sensitivity and increasing specificity of the test. Nitroglycerine significantly raised tilt testing sensitivity by maintaining a similar specificity in comparison to isoproterenol.

CONCLUSIONS

The results from this meta-analysis show the high overall performance of HUT for diagnosing vasovagal syncope. Our findings provide useful information for evaluating clinical and instrumental parameters together with pharmacological stressors influencing HUT accuracy. This could allow the drawing of tilt testing protocols tailored on the diagnostic needs of each patient with unexplained syncope.

Syncope and near-syncope as a multifactorial problem in geriatric inpatients: Systemic hypotension is an underrated predictor for syncope exclusively

PURPOSE

Syncope (SC) and near-syncope (NS) are still misunderstood syndromes. Aim of study was to determine the risk factors for SC, NS, as well as for both entities (SC/NS) in geriatric inpatients reporting these events within the last year, irrespectively of the reason of admission to hospital.

MATERIAL AND METHODS

The retrospective study covered 250 patients, consecutively admitted to the geriatric ward. Patients were assigned to the three models: SC and/or NS in total, n=106; isolated NS, n=72; SC with co-existing NS, if any, n=34, and compared with patients without any such events (n=144). The patients underwent a comprehensive geriatric assessment and complete clinical investigation. The binary logistic regression was applied to predict risk factors for each of the models.

RESULTS

Falls were most predictive for NS model (OR 35.4; 95% CI 10.3-121.1), and systemic hypotension for SC model (OR 92.9; 95% CI 6.1-1421.0). The highest specificity (85%) and sensitivity (81%) were found for the SC/NS model, with the highest contribution by falls (OR 18.1; 95% CI, 7.6-45.2), orthostatic hypotension (OR 8.1; 95% CI, 3.5-18.5), a history of stroke or transient ischemic attack, treatment with an angiotensin receptor blocker, plasma creatinine >1.4mg/dL, negatively self-rated health, vertigo, pathology of carotid arteries, and lack of hypertension.

CONCLUSIONS

Syncope and near-syncope in geriatric inpatients have multifactorial and cumulative aetiology, with blurred, frequently overlapping boundaries between them. The falls, postural hypotension, and/or brain hypoperfusion of different origin seem to be most predictive of the both events, however low systemic blood pressure was predictive for the syncope exclusively.

Carotid sinus syndrome is common in very elderly patients undergoing tilt table testing and carotid sinus massage because of syncope or unexplained falls

BACKGROUND AND AIMS

Although the incidence of falls and syncope increase with age, the underlying mechanisms are not fully understood, particularly in very old patients. We report diagnostic outcomes of tilt table and carotid sinus massage (TT/CSM) testing in a population of older old subjects (82% over 80 years of age) referred for TT/CSM from a falls clinic for assessment of syncope or unexplained falls.

METHODS

Prospective observational study between January 1, 2001 and January 1, 2005 involving 290 consecutive subjects undergoing TT/CSM testing according to European Society of Cardiology guidelines for the diagnosis and management of syncope.

RESULTS

Combination of TT/CSM provided a positive result in 62% of subjects, and was significantly more likely to be positive in subjects over the age of 80 (68% vs 50%, p=0.001). Carotid sinus syndrome (CSS) was the most common diagnosis, and was significantly more common in subjects over 80 (48% vs 34%, p=0.022) particularly due to a higher incidence of mixed CSS (16% vs 7%, p=0.023). There was no significant difference in the diagnosis of subjects referred due to falls and those reporting syncope (p=0.93). No cardiovascular or neurological adverse events occurred.

CONCLUSIONS

In our cohort of very elderly patients, the diagnostic accuracy of tilt testing and carotid sinus massage was high and adverse incidents absent when testing was indicated by a geriatrician experienced in the assessment of falls and syncope. We advocate the use of TT/CSM testing as part of a comprehensive falls/syncope assessment for the diagnostic evaluation of older patients presenting with unexplained falls and/or syncope in whom structured assessment has not identified a cause for their symptoms.

Management and therapy of vasovagal syncope: A review

Vasovagal syncope is a common cause of recurrent syncope. Clinically, these episodes may present as an isolated event with an identifiable trigger, or manifest as a cluster of recurrent episodes warranting intensive evaluation. The mechanism of vasovagal syncope is incompletely understood. Diagnostic tools such as implantable loop recorders may facilitate the identification of patients with arrhythmia mimicking benign vasovagal syncope. This review focuses on the management of vasovagal syncope and discusses the non-pharmacological and pharmacological treatment options, especially the use of midodrine and selective serotonin reuptake inhibitors. The role of cardiac pacing may be meaningful for a subgroup of patients who manifest severe bradycardia or asystole but this still remains controversial.

Vasovagal syncope in the older person: differences in presentation between older and younger patients

BACKGROUND

vasovagal syncope (VVS) has been diagnosed with increasing frequency in older people since the description of the head-up tilt table test (HUTT). There is, however, a paucity of research describing the clinical features of VVS in this group. To address this issue, we investigated the age distribution and differences in clinical characteristics associated with age in patients diagnosed with VVS by HUTT at our tertiary referral centre.

METHODS

1,060 consecutive patients with tilt-positive VVS were identified from a prospective database containing the demographic and clinical information of individuals assessed in our unit over a 10-year period. VVS was diagnosed with appropriate haemodynamic changes during HUTT and accompanying symptom reproduction.

RESULTS

we found a bimodal age distribution with a small peak at 20-29 years and a larger peak at 70-79 years. Patients aged > or =60 years were less likely to report total loss of consciousness [odds ratio (OR) 0.50, 95% confidence interval (CI) = 0.38-0.64], near loss of consciousness (OR 0.53, 95% CI = 0.40-0.70) or palpitations (OR 0.45, 95% CI = 0.28-0.72) and more likely to present with unexplained falls (OR 2.33, 95% CI = 1.36-4.32). The typical provoking factors of prolonged standing (OR 0.55, 95% CI = 0.40-0.72), posture change (OR 0.61, 95% CI = 0.46-0.82) and hot environments (OR 0.57, 95% CI = 0.42-0.78) were also less common in older patients.

CONCLUSION

in our large study population, VVS was more common in older patients. The clinical presentation differed significantly between the two groups. Older patients were less likely to give a typical history and therefore clinicians need to have a high index of suspicion when evaluating the older patient presenting with collapse or unexplained falls.

Influence of age on syncope following prolonged exercise: differential responses but similar orthostatic intolerance

Orthostatic tolerance is reduced with increasing age and following prolonged exercise. The aim of this study was to determine the effect of age on cardiovascular and cerebrovascular responses to orthostatic stress following prolonged exercise. Measurements were obtained before, and within 45 min after, 4 h of continuous running at 70-80% of maximal heart rate in nine young (Y; 27 +/- 4 years; V(O(2)max)) 59 +/- 10 ml kg(1) min(1)) and twelve older (O; 65 +/- 5 years; V(O(2)max)) 46 +/- 8 ml kg(1) min(1)) athletes. Middle cerebral artery blood flow velocity (MCAv; transcranial Doppler ultrasound), blood pressure (BP; Finometer) and stroke volume (SV) were measured continuously whilst supine and during 60 deg head-up tilt for 15 min or to pre-syncope. Orthostatic tolerance was reduced post-exercise (tilt completed (min:s, mean +/- s.d.): Pre, 14:39 +/- 0:55; Post, 5:59 +/- 4:53; P < 0.05), but did not differ with age (P > 0.05). Despite a 25% higher supine MCAv in the young, MCAv at syncope was the same in both groups (Y: 34 +/- 10 cm s(1); O: 32 +/- 13; P > 0.05). Although the hypotensive response to syncope did not differ with age, the components of BP did; SV was lowered more in the young (Y: -57 +/- 16%; O: -34 +/- 13%; P < 0.05); and total peripheral resistance was lowered in the older athletes but was unchanged in the young (Y: +8 +/- 10%; O: -21 +/- 12%; (at 10 s pre-syncope) P < 0.05). Despite a lower MCAv in the older athletes, time to syncope was similar between groups; however, the integrative mechanisms responsible for syncope did differ with age. The similar MCAv at pre-syncope indicates there is an age-independent critical cerebral blood flow threshold at which syncope occurs.

Clinical efficacy of beta1 selective adrenergic blockers in the treatment of neurocardiogenic syncope - a meta-analysis

BACKGROUND

Beta1 (B(1)) selective blockers have been widely used for the treatment of neurocardiogenic syncope though clinical trials have shown conflicting degrees of efficacy.

OBJECTIVE

To study the clinical efficacy of B(1) selective blockers compared to placebo in the treatment of neurocardiogenic syncope.

METHODS

Four placebo controlled randomized studies were identified after search of existing English language literature. Review Manager (RevMan version 5, Oxford, England) was used for statistical calculations. Both random and fixed effects models were used for analysis.

RESULTS

There was no demonstrable efficacy of B(1) blockers compared to placebo even after a pre-specified sensitivity analysis. There was a trend towards more adverse events in the beta blocker group compared to placebo (OR = 2.03 CI = 0.83-3.95, p = 0.12).

CONCLUSION

There is no clinical evidence for justifying the use of B(1) selective blockers in the treatment of adult neurocardiogenic syncope. These agents may in fact lead to a higher rate of adverse events compared to placebo.

Home orthostatic training in chronic fatigue syndrome--a randomized, placebo-controlled feasibility study

BACKGROUND

Orthostatic (Tilt)-training is an effective treatment for neurally mediated hypotension (NMH). NMH is a frequent finding in chronic fatigue syndrome (CFS). We evaluated home orthostatic training (HOT) in CFS in a randomized placebo-controlled feasibility study.

METHODS

Thirty-eight patients with CFS (Fukuda Criteria) were randomly allocated to daily tilt training (n = 19) or sham training (n = 19) for 6 months. Haemodynamic responses to standing were performed in all subjects using continuous technology (Taskforce) at enrolment, week 1, 4 and 24. Symptom response and compliance were assessed using diaries.

RESULTS

Two patients (one from each arm) withdrew from the study. Fourteen patients in each group complied completely or partially, and patients found the training manageable and achievable. Compared to the sham group, blood pressure while standing dropped to 8.0 mmHg less in the HOT group at 4 weeks (95% CI: 1.0 to 15.0, P = 0.03). At 4 weeks, the HOT group had higher total peripheral resistance compared to the sham group; mean difference 70.2, 95% CI: -371.4 to 511.8. Changes were maintained at 6 months. There was no significant difference in fatigue between groups at 4 weeks (mean difference 1.4, 95% CI: -13.5 to 16.2), but there was a trend towards improvement in fatigue at 6 months. Compliers had lower fatigue compared to non-compliers.

CONCLUSIONS

A placebo-controlled study of HOT in CFS is feasible. HOT is well tolerated and generally complied with. A likely physiological rationale for HOT in CFS is related to reductions in orthostatic intolerance. An adequately powered study including strategies to enhance compliance is warranted.

Impedance cardiography: a role in vasovagal syncope diagnosis?

BACKGROUND

vasovagal syncope is the most common cause of syncope in all age groups, with diagnosis usually based on history, examination and basic investigations to exclude alternative causes of syncope. Where doubt exists, the head-up tilt (HUT) test is used for diagnosis but is time consuming and lacks a gold standard to accurately assess sensitivity and specificity. Alternative methods of diagnosing vasovagal syncope would thus be useful.

OBJECTIVE

to investigate the potential for impedance cardiography (ICG)-derived haemodynamic measures to predict HUT test outcome in unexplained syncope.

DESIGN

prospective controlled study.

SUBJECTS

eighty-six patients with unexplained syncope and 43 non-syncopal controls.

METHODS

all subjects underwent continuous heart rate, blood pressure and ICG measurements during 10 min supine rest and during HUT. Vasovagal syncope was diagnosed when patients experienced symptom reproduction with concomitant haemodynamic derangements.

RESULTS

during rest prior to HUT, the syncopal group had higher mean heart rate (P = 0.0008) and lower baroreceptor effectiveness index (P < 0.0001) compared to non-syncopal controls. On comparing patients who presented with unexplained syncope who subsequently had a positive HUT (therefore a diagnosis of vasovagal syncope 55 [64%]; mean age 47 years, range 17-85) to those having a negative tilt test (n = 31; mean age 47 years, range 17-88), there were no significant differences found in cardiovascular or autonomic parameters prior to HUT. A predictive ROC curve model at a 85% threshold allowed using cardiac index (CI), end-diastolic index (EDI) and left ventricular work index (LVWI) would identify those who would have a positive HUT from baseline cardiovascular measurements (CI >3.5, EDI > 77, LVWI >4.7) with 93% sensitivity and 17% specificity.

CONCLUSION

supine haemodynamic measures derived from transthoracic ICG can simply, non-invasively and sensitively differentiate HUT-positive patients from those with negative tilt tests. Further work is needed, particularly in older patients, before this technique can be used in clinical practice.

Neurally mediated syncope as a cause of syncope in patients with Brugada electrocardiogram

INTRODUCTION

Patients with type 1 Brugada electrocardiogram (ECG) and an episode of syncope are diagnosed as symptomatic Brugada syndrome; however, all episodes of syncope may not be due to ventricular tachyarrhythmia.

METHODS AND RESULTS

Forty-six patients with type 1 Brugada ECG (all males, 51 +/- 13 years, 29 spontaneous, 17 Ic-drug induced), 20 healthy control subjects (all males, 35 +/- 11 years), and 15 patients with suspected neurally mediated syncope (NMS; 9 males, 54 +/- 22 years) underwent the head-up tilt (HUT) test. During the HUT test, 12-lead ECGs were recorded in all patients, and the heart rate variability was investigated in some patients. Sixteen (35%) of 46 patients with Brugada ECG, 2 (10%) of 20 control subjects, and 10 (67%) of 15 patients with suspected NMS showed positive responses to the HUT test. Although no significant differences were observed in HUT-positive rate among Brugada patients with documented VT (7/14; 50%), syncope (5/19; 26%) and asymptomatic patients (4/13; 31%), the HUT-positive rate was significantly higher in patients with documented VT (50%) and those with VT or no symptoms (11/27, 41%) compared to that in control subjects (10%) (P < 0.05). Augmentation of ST-segment amplitude (> or =0.05 mV) in leads V1-V3 was observed in 11 (69%) of 16 HUT-positive patients with Brugada ECG during vasovagal responses, and was associated with augmentation of parasympathetic tone following sympathetic withdrawal.

CONCLUSION

Thirty-five percent of patients with Brugada ECG showed vasovagal responses during the HUT test, suggesting that some Brugada patients have impaired balance of autonomic nervous system, which may relate to their syncopal episodes.