Diagnosing syncope. Part 2: Unexplained syncope. Clinical Efficacy Assessment Project of the American College of Physicians

Research progress in diagnosis and treatment of psychogenic pseudosyncope in children

Psychogenic pseudosyncope is one of the primary causes of transient loss of consciousness in children and adolescents, essentially classified as a conversion disorder that significantly impacts patients' quality of life. Clinically, psychogenic pseudosyncope shares certain similarities with vasovagal syncope in terms of pre-syncope symptoms and triggers, making it sometimes difficult to differentiate and easily misdiagnosed. Therefore, placing emphasis upon the characteristics of psychogenic pseudosyncope is crucial for early identification and treatment, which holds significant importance for the mental and psychological health of children and adolescents. In the present review, we aimed to address psychogenic pseudosyncope with clinical features, diagnosis, and treatment.

Risk-stratification tools for emergency department patients with syncope: A systematic review and meta-analysis of direct evidence for SAEM GRACE

OBJECTIVES

Approximately 10% of patients with syncope have serious or life-threatening causes that may not be apparent during the initial emergency department (ED) assessment. Consequently, researchers have developed clinical decision rules (CDRs) to predict adverse outcomes and risk stratify ED syncope patients. This systematic review and meta-analysis (SRMA) aims to cohere and synthesize the best current evidence regarding the methodological quality and predictive accuracy of CDRs for developing an evidence-based ED syncope management guideline.

METHODS

We conducted a systematic literature search according to the patient-intervention-control-outcome question: In patients 16 years of age or older who present to the ED with syncope for whom no underlying serious/life-threatening condition was found during the index ED visit (population), are risk stratification tools (intervention), better than unstructured clinical judgment (i.e., usual care; comparison), for providing accurate prognosis and aiding disposition decision for outcomes within 30 days (outcome)? Two reviewers independently assessed articles for inclusion and methodological quality. We performed statistical analysis using Meta-DiSc. We used GRADEPro GDT software to determine the certainty of the evidence and create a summary of the findings (SoF) tables.

RESULTS

Of 2047 publications obtained through the search strategy, 31 comprising 13 CDRs met the inclusion criteria. There were 13 derivation studies (17,578 participants) and 24 validation studies (14,845 participants). Only three CDRs were validated in more than two studies. The San Francisco Syncope Rule (SFSR) was validated in 12 studies: positive likelihood ratio (LR+) 1.15-4.70 and negative likelihood ratio (LR-) 0.03-0.64. The Canadian Syncope Risk Score (CSRS) was validated in five studies: LR+ 1.15-2.58 and LR- 0.05-0.50. The Osservatorio Epidemiologico sulla Sincope nel Lazio (OESIL) risk score was validated in five studies: LR+ 1.16-3.32 and LR- 0.14-0.46.

CONCLUSIONS

Most CDRs for ED adult syncope management have low-quality evidence for routine clinical practice use. Only three CDRs (SFSR, CSRS, OESIL) are validated by more than two studies, with significant overlap in operating characteristics.

Correlation between percutaneous patent foramen ovale closure and recurrence of unexplained syncope

Background

The relationship between patent foramen ovale (PFO) and unexplained syncope remains to be illustrated. Therefore, this study aimed to explore the outcomes and prognostic factors for syncope recurrence after PFO closure.

Methods

Patients with both large right-to-left shunting (RLS) PFO and unexplained syncope who visited the cardiovascular department of Xiangya Hospital Central South University from 1 January 2017 to 31 December 2021 were consecutively enrolled in our study. The recurrence rate of syncope was compared between the non-closure group (n = 20) and the closure group (n = 91).

Results

A total of 111 patients were finally included. After 31.11 ± 14.30 months of follow-up, only 11% of patients in the closure group had recurrent syncope, which was much lower than that of the non-closure group (11.0 vs. 35%, P = 0.018). We further investigated the possible prognostic factors for syncope recurrence in the closure group and found syncope occurring more than five times preoperatively, hypertension, and residual RLS at 12-month follow-up were significantly correlated with a higher number of recurrences.

Conclusions

PFO closure reduced the recurrence rate of unexplained syncope. The efficacy of prevention was prognosticated by factors including the presence or absence of syncope induction, the frequency of syncope episodes, and the presence or absence of hypertension. Syncope recurrence was also related to residual shunts post closure.

Holter ECG for Syncope Evaluation in the Internal Medicine Department-Choosing the Right Patients

Physicians use Holter electrocardiography (ECG) monitoring to evaluate some patients with syncope in the internal medicine department. We questioned whether Holter ECG should be used in the presented setting. Included were all consecutive patients admitted with syncope to one of our nine internal medicine departments who had completed a 24 h Holter ECG between 2018 and 2021. A diagnostic Holter was defined as one which altered the patient’s treatment and met ESC/ACC/AHA diagnostic criteria. A total of 478 Holter tests were performed for syncope evaluation during admission to an internal medicine department in the study period. Of them, 25 patients (5.2%) had a diagnostic Holter finding. Sinus node dysfunction was the most frequent diagnostic recording (13 patients, 52%). In multivariant analysis, predictors for diagnostic Holter were older age (OR 1.35, 95% CI 1.08−1.68), heart failure with preserved ejection fraction (OR 4.1, 95% CI 1.43−11.72), and shorter duration to Holter initiation (OR 0.73, 95% CI 0.56−0.96). There was a positive correlation between time from admission to Holter and hospital stay, r(479) = 0.342, p < 0.001. Our results suggest that completing a 24 h Holter monitoring during admission to the internal medicine department should be restricted to patients with a high pre-test probability to avoid overuse and possible harm.

First Reported Case of Deglutition Syncope With Underlying Suppurative Parotitis

Deglutition syncope and carotid sinus hypersensitivity are neurally mediated events, leading to potentially dangerous arrhythmias and cardiovascular events. Mostly related to underlying gastroesophageal or cardiovascular causes, sometimes, this might not be the case. We report the first-ever documented case of deglutition syncope with acute suppurative parotitis, which resolved after resolving the parotid gland's swelling.

Permanent pacemaker implantation in unexplained syncope patients with borderline sinus bradycardia and electrophysiology study-proven sinus node disease

BACKGROUND

Significant sinus bradycardia (SB) in the context of sinus node dysfunction (SND) has been associated with neurological symptoms. The objective was to evaluate the effect of permanent pacing on the incidence of syncope in patients with rather mild degrees of SB, unexplained syncope, and "positive" invasive electrophysiologic testing.

METHODS

This was an observational study based on a prospective registry of 122 consecutive mild SB patients (61.90 ± 18.28 years, 61.5% male, 57.88 ± 7.73 bpm) presenting with recurrent unexplained pre and syncope attacks admitted to our hospital for invasive electrophysiology study (EPS). Τhe implantation of a permanent antibradycardia pacemaker (ABP) was offered to all patients according to the results of the EPS. Eighty patients received the ABP, while 42 denied.

RESULTS

The mean of reported syncope episodes was 2.23 ± 1.29 (or presyncope 2.36 ± 1.20) in the last 12 months before they were referred for a combined EP guided diagnostic and therapeutic approach. Over a mean follow-up of approximately 4 years (50.39 ± 32.40 months), the primary outcome event (syncope) occurred in 18 of 122 patients (14.8%), 6 of 80 (7.5%) in the ABP group as compared to 12 of 42 (28.6%) in the no pacemaker group (P = .002).

CONCLUSIONS

Among patients with mild degree of SB and a history of unexplained syncope, a set of positivity criteria for the presence of EPS defined SND after differentiating reflex syncope, identifies a subset of patients who will benefit from permanent pacing.

Near-infrared spectroscopy in evaluating psychogenic pseudosyncope-a novel diagnostic approach

BACKGROUND

Psychogenic pseudosyncope (PPS), a conversion disorder and syncope mimic, accounts for a large proportion of 'unexplained syncope'. PPS is diagnosed by reproduction of patients' symptoms during head-up tilt (HUT). Electroencephalogram (EEG), a time consuming and resource intensive technology, is used during HUT to demonstrate absence of cerebral hypoperfusion during transient loss of consciousness (TLOC). Near-infrared spectroscopy (NIRS) is a simple, non-invasive technology for continuous monitoring of cerebral perfusion. We present a series of patients for whom PPS diagnosis was supported by NIRS during HUT.

METHODS

Eight consecutive patients with suspected PPS referred to a syncope unit underwent evaluation. During HUT, continuous beat-to-beat blood pressure (BP), heart rate (HR) and NIRS-derived tissue saturation index (TSI) were measured. BP, HR and TSI at baseline, time of first symptom, presyncope and apparent TLOC were measured. Patients were given feedback and followed for symptom recurrence.

RESULTS

Eight predominantly female patients (6/8, 75%) aged 31 years (16-54) were studied with (5/8, 63%) having comorbid psychiatric diagnoses, and (5/8, 63%) presenting with frequent episodes of prolonged TLOC with eyes closed (6/8, 75%). All patients experienced reproduction of typical events during HUT. Systolic BP (mmHg) increased from baseline (129.7 (interquartile range [IQR] 124.9-133.4)) at TLOC (153.0 (IQR 146.7-159.0)) (P-value = 0.012). HR (bpm) increased from baseline 78 (IQR 68.6-90.0) to 115.7 (IQR 93.5-127.9) (P-value = 0.012). TSI (%) remained stable throughout, 71.4 (IQR 67.5-72.9) at baseline vs. 71.0 (IQR 68.2-73.0) at TLOC (P-value = 0.484).

CONCLUSIONS

NIRS provides a non-invasive surrogate of cerebral perfusion during HUT. We propose HUT incorporating NIRS monitoring in the diagnostic algorithm for patients with suspected PPS.

When Is Syncope Arrhythmic?

Cardiac arrhythmia is a common cause of syncope. The prompt identification of arrhythmic syncope has diagnostic and prognostic implications. In this article, an approach to identifying and managing arrhythmic syncope is discussed, including key findings from the history, physical examination, electrocardiogram, role of risk stratification, use of supplemental investigations, and treatment.

Recommendations for the use of electrophysiological study: Update 2018

The field of cardiac electrophysiology has greatly developed during the past decades. Consequently, the use of electrophysiological studies (EPSs) in clinical practice has also significantly augmented, with a progressively increasing number of certified electrophysiology centers and specialists. Since Zipes et al published the Guidelines for Clinical Intracardiac Electrophysiology and Catheter Ablation Procedures in 1995, no official document summarizing current EPS indications has been published. The current paper focuses on summarizing all relevant data of the role of EPS in patients with different types of cardiac pathologies and provides up-to-date recommendations on this topic. For this purpose, the PubMed database was screened for relevant articles in English up to December 2018 and ESC and ACC/AHA Clinical Practice Guidelines, and EHRA/HRS/APHRS position statements related to the current topic were analyzed. Current recommendations for the use of EPS in clinical practice are discussed and presented in 17 distinct cardiac pathologies. A short rationale, evidence, and indications are provided for each cardiac disease/group of diseases. In conclusion, because of its capability to establish a diagnosis in patients with a variety of cardiac pathologies, the EPS remains a useful tool in the evaluation of patients with cardiac arrhythmias and conduction disorders and is capable of establishing indications for cardiac device implantation and guide catheter ablation procedures.

Predictors of Clinically Significant Echocardiography Findings in Older Adults with Syncope: A Secondary Analysis

BACKGROUND

Syncope is a common reason for visiting the emergency department (ED) and is associated with significant healthcare resource utilization.

OBJECTIVE

To develop a risk-stratification tool for clinically significant findings on echocardiography among older adults presenting to the ED with syncope or nearsyncope.

DESIGN

Prospective, observational cohort study from April 2013 to September 2016.

SETTING

Eleven EDs in the United States.

PATIENTS

We enrolled adults (=60 years) who presented to the ED with syncope or near-syncope who underwent transthoracic echocardiography (TTE).

MEASUREMENTS

The primary outcome was a clinically significant finding on TTE. Clinical, electrocardiogram, and laboratory variables were also collected. Multivariable logistic regression analysis was used to identify predictors of significant findings on echocardiography.

RESULTS

A total of 3,686 patients were enrolled. Of these, 995 (27%) received echocardiography, and 215 (22%) had a significant finding on echocardiography. Regression analysis identified five predictors of significant finding: (1) history of congestive heart failure, (2) history of coronary artery disease, (3) abnormal electrocardiogram, (4) high-sensitivity troponin-T >14 pg/mL, and 5) N-terminal pro B-type natriuretic peptide >125 pg/mL. These five variables make up the ROMEO (Risk Of Major Echocardiography findings in Older adults with syncope) criteria. The sensitivity of a ROMEO score of zero for excluding significant findings on echocardiography was 99.5% (95% CI: 97.4%-99.9%) with a specificity of 15.4% (95% CI: 13.0%-18.1%).

CONCLUSIONS

If validated, this risk-stratification tool could help clinicians determine which syncope patients are at very low risk of having clinically significant findings on echocardiography.

REGISTRATION

ClinicalTrials.gov Identifier NCT01802398.

Vasovagal syncope is associated with poor prognosis in patients with left ventricular dysfunction

Vasovagal syncope (VVS) is known to have a benign prognosis and be associated with enhanced contraction and activation of the left ventricular (LV) mechanoreceptors. However, a little is known about VVS in patients with LV dysfunction. The present study aimed to investigate the prevalence and prognosis of VVS in patients with LV dysfunction. We enrolled 368 patients with unexplained syncope. In 7 of these patients, LV ejection fraction was lower than 40%. The results of a head-up tilt test (HUT) and the recurrence of syncope were compared between these 7 patients with LV dysfunction and the remaining patients. Positive HUT was obtained in the 6 patients (86%) with LV dysfunction; this rate tended to be higher as compared with normal cardiac function (192/361, 53%, P = 0.069). In patients with LV dysfunction, response in HUT was mostly vasodepressor type (62%); however, most of HUT responses were mixed type in patients with normal LV function (67%). Among patients with positive HUT, the recurrent rate of syncope after HUT was higher in those with LV dysfunction than in those with normal LV function (67 vs. 21%, P = 0.008). VVS in patients with LV dysfunction may be refractory to treatment and could be associated with poor prognosis.

Permanent pacemaker implantation in octogenarians with unexplained syncope and positive electrophysiologic testing

BACKGROUND

Syncope is a common problem in the elderly, and a permanent pacemaker is a therapeutic option when a bradycardic etiology is revealed. However, the benefit of pacing when no association of symptoms to bradycardia has been shown is not clear, especially in the elderly.

OBJECTIVE

The aim of this study was to evaluate the effect of pacing on syncope-free mortality in patients aged 80 years or older with unexplained syncope and "positive" invasive electrophysiologic testing (EPT).

METHODS

This was an observational study. A positive EPT for the purposes of this study was defined by at least 1 of the following: a corrected sinus node recovery time of >525 ms, a basic HV interval of >55 ms, detection of infra-Hisian block, or appearance of second-degree atrioventricular block on atrial decremental pacing at a paced cycle length of >400 ms.

RESULTS

Among the 2435 screened patients, 228 eligible patients were identified, 145 of whom were implanted with a pacemaker. Kaplan-Meier analysis determined that time to event (syncope or death) was 50.1 months (95% confidence interval 45.4-54.8 months) with a pacemaker vs 37.8 months (95% confidence interval 31.3-44.4 months) without a pacemaker (log-rank test, P = .001). The 4-year time-dependent estimate of the rate of syncope was 12% vs 44% (P < .001) and that of any-cause death was 41% vs 56% (P = .023), respectively. The multivariable odds ratio was 0.25 (95% confidence interval 0.15-0.40) after adjustment for potential confounders.

CONCLUSION

In patients with unexplained syncope and signs of sinus node dysfunction or impaired atrioventricular conduction on invasive EPT, pacemaker implantation was independently associated with longer syncope-free survival. Significant differences were also shown in the individual components of the primary outcome measure (syncope and death from any cause).

[Implantable loop recorders in the diagnosis of syncope]

In syncope patients, it is essential to make the right diagnosis with respect to underlying etiology. Cardiac (arrhythmic and structural) syncopal episodes carry untoward prognostic implication compared with reflex syncope. While rhythm-symptom correlation of a spontaneous syncopal episode is key to making the correct diagnosis, in case of unclear syncope the early implantation of a loop recorder leads to faster, more efficacious, and more cost-effective diagnosis. This review article summarizes the current data regarding diagnostic accuracy and clinical role of implantable loop recorders. It outlines the superiority of loop recorders in the management of unclear syncope according to present knowledge.

Nationwide Trends in Syncope Hospitalizations and Outcomes From 2004 to 2014

BACKGROUND

We examined the prevalence, comorbidity burden, and outcomes of patients who presented to acute care hospitals with a primary diagnosis of syncope over a 10-year period in Canada.

METHODS

The Canadian Institute for Health Information Discharge Abstract Database (which contains detailed health information from all Canadian provinces and territories except Quebec) was used to identify hospitalizations of patients with a primary diagnosis of syncope (International Classification of Diseases-10th Revision code R55) 20 years of age or older in Canada from 2004 to 2014. Annual age- and sex-standardized hospital discharge rates were calculated. Logistic regression was used to examine patient factors associated with in-hospital mortality, 30-day readmission for any cause, and syncope.

RESULTS

During the 10-year study period, 98,730 hospitalizations occurred for syncope. The age- and sex-standardized hospitalization rate was 0.54 per 1000 population and decreased over time (P < 0.0001). Most patients (63%) were low-risk (Charlson comorbidity index = 0), although the proportion of patients with a Charlson comorbidity index ≥ 3 increased over time. Less than 1% of patients died in-hospital; however, among patients discharged alive, 30-day readmission rates for syncope and any cause were 1.1% and 9.0%, respectively. In-hospital mortality increased with each decade in age (odd ratio, 1.63; 95% confidence interval, 1.48-1.79), was higher in men (odds ratio, 1.37; 95% confidence interval, 1.16-1.63), and in patients with greater comorbidity (P < .0001).

CONCLUSIONS

The hospitalization rate for syncope is decreasing over time in Canada. Although the comorbidity burden of hospitalized patients is increasing, most syncope patients are low-risk. Future studies are needed to help understand how standardized diagnostic testing pathways and discharge planning might lead to more efficient and cost-effective syncope management.

Reliability of Clinical Assessments in Older Adults With Syncope or Near Syncope

OBJECTIVES

Clinical prediction models for risk stratification of older adults with syncope or near syncope may improve resource utilization and management. Predictors considered for inclusion into such models must be reliable. Our primary objective was to evaluate the inter-rater agreement of historical, physical examination, and electrocardiogram (ECG) findings in older adults undergoing emergency department (ED) evaluation for syncope or near syncope. Our secondary objective was to assess the level of agreement between clinicians on the patient's overall risk for death or serious cardiac outcomes.

METHODS

We conducted a cross-sectional study at 11 EDs in adults 60 years of age or older who presented with unexplained syncope or near syncope. We excluded patients with a presumptive cause of syncope (e.g., seizure) or if they were unable or unwilling to follow-up. Evaluations of the patient's past medical history and current medication use were completed by treating provider and trained research associate pairs. Evaluations of the patient's physical examination and ECG interpretation were completed by attending/resident, attending/advanced practice provider, or attending/attending pairs. All evaluations were blinded to the responses from the other rater. We calculated the percent agreement and kappa statistic for binary variables. Inter-rater agreement was considered acceptable if the kappa statistic was 0.6 or higher.

RESULTS

We obtained paired observations from 255 patients; mean (±SD) age was 73 (±9) years, 137 (54%) were male, and 204 (80%) were admitted to the hospital. Acceptable agreement was achieved in 18 of the 21 (86%) past medical history and current medication findings, none of the 10 physical examination variables, and three of the 13 (23%) ECG interpretation variables. There was moderate agreement (Spearman correlation coefficient, r = 0.40) between clinicians on the patient's probability of 30-day death or serious cardiac outcome, although as the probability increased, there was less agreement.

CONCLUSIONS

Acceptable agreement between raters was more commonly achieved with historical rather than physical examination or ECG interpretation variables. Clinicians had moderate agreement in assessing the patient's overall risk for a serious outcome at 30 days. Future development of clinical prediction models in older adults with syncope should account for variability of assessments between raters and consider the use of objective clinical variables.

Convulsive Syncope Induced by Ventricular Arrhythmia Masquerading as Epileptic Seizures: Case Report and Literature Review

It is important but difficult to distinguish convulsive syncope from epileptic seizure in many patients. We report a case of a man who presented to emergency department after several witnessed seizure-like episodes. He had a previous medical history of systolic heart failure and automated implantable converter defibrillator (AICD) in situ. The differential diagnoses raised were epileptic seizures and convulsive syncope secondary to cardiac arrhythmia. Subsequent AICD interrogation revealed ventricular tachycardia and fibrillation (v-tach/fib). Since convulsive syncope and epileptic seizure share many similar clinical features, early diagnosis is critical for choosing the appropriate management and preventing sudden cardiac death in patients with presumed epileptic seizure.

Vascular Analysis of Individuals with Drop Attacks

The authors used magnetic resonance angiography to examine the intracranial and cervical vascular structures of individuals who suffer from drop attacks. Normal structural configurations of the circle of Willis and the vertebrobasilar arterial system were compared to the vascular patterns of 10 subjects with these episodic tonic or atonic attacks. Overall, multiple areas of arterial occlusion, stenosis, or hypoplasia were visualized in the images of 8 of the 10 subjects. Specific anomalies of the vertebral and basilar arteries were identified in 4 individuals, and 8 images depicted nonvisualization of the posterior communicating arteries. We suggest that the pathological aberrations in the regional circulation of the hindbrain support the hypothesis that a transient hypovolemic episode may have an impact upon the neural activity involved in maintenance of motor tone and postural stability.

Implantable Loop Recorder – A Good Opportunity to Diagnose Unexplained Syncope

Implantable loop recorder (ILR) is a method in cardiology, which is used for the diagnosis of unexplained syncope in patients who were not treated successfully using standard methods. Implantable loop recorder is a diagnostic device that is surgically implanted under the skin of the chest area. This device does not have the endovenous implantation of electrodes; instead, electrodes are attached to the machine housing. The device records the heart rhythm continuously, up to 14 months, and stores data outside the activator whenever symptoms appear, or by the automatic activation of the predefined program for bradycardia, asystole, and tachycardia. The aim of this paper was to describe the method for the detection of cardiac syncope with the use of implantable loop recorder.

Syncope: a review of emergency department management and disposition

Syncope is defined as a transient loss of consciousness due to cerebral hypoperfusion with spontaneous return to baseline function without intervention. It is a common chief complaint of patients presenting to the emergency department. The differential diagnosis for syncope is broad and the management varies significantly depending on the underlying etiology. In the emergency department, determining the cause of a syncopal episode can be difficult. However, a thorough history and certain physical exam findings can assist in evaluating for life-threatening diagnoses. Risk-stratifying patients into low, moderate and high-risk groups can assist in medical decision making and help determine the patient's disposition. Advancements in ambulatory monitoring have made it possible to obtain prolonged cardiac evaluations of patients in the outpatient setting. This review will focus on the diagnosis and management of the various types of syncope.

The Role of the Syncope Management Unit

Syncope is a common symptom, experienced by 15% of persons less than 18 years old and up to 23% of elderly nursing home residents, so it is important to consider optimizing strategies for the management of these patients. The strategy selected will inevitably differ from place to place. However, an organized structure offers more cost-effective care. This article discusses possible health care delivery models for syncope management and reviews the current status of the organization of syncope care, to show the value of a multidisciplinary approach to the organized management of patients with syncope.

Syncope in Patients with Organic Heart Disease

Patients with syncope and organic heart disease remain a small but important subset of those patients who experience transient loss of consciousness. These patients require thoughtful and complete evaluation in an attempt to better understand the mechanism of syncope and its relationship to the underlying disease, and to diagnose and treat both properly. The goal is to reduce the risk of further syncope, to improve long-term outcomes with respect to arrhythmic and total mortality, and to improve patients' quality of life.

Acute myocardial infarction in patients with syncope

Objective:

We sought to determine the incidence of acute myocardial infarction (AMI) in emergency department (ED) patients with syncope, the characteristics of these AMIs and how helpful the initial electrocardiogram (ECG) was in identifying these cases.

Methods:

In a prospective cohort of consecutive patients with syncope, the initial ECG was found to be abnormal using a prespecified definition (any nonsinus rhythm or any new or age-indeterminate abnormalities). Patients were then followed up to identify an AMI diagnosed within 30 days of presentation.

Results:

There were 1474 consecutive patient visits for syncope or near-syncope over a 45-month period spanning from Jul. 1, 2000, to Feb. 28, 2002, and Jul. 15, 2002, to Aug. 31, 2004, of which 46 (3.1%) were diagnosed with AMI. The majority of the AMI patients (42) had no ST segment elevation. The initial ECG was abnormal in 37 out of 46 cases. The diagnostic performance of the initial ECG was sensitivity 80% (95% confidence interval [CI] 67%–89%), specificity 64% (95% CI 61%–67%), negative predictive value 99% (95% CI 98%–100%), positive predictive value 7% (95% CI 6%–8%), positive likelihood ratio 2.2 (95% CI 1.6–2.5) and negative likelihood ratio 0.3 (95% CI 0.2–0.5).

Conclusion:

The incidence of AMI in patients presenting with syncope is low. A normal ECG has a high negative predictive value, although its sensitivity is limited.

How can we improve management of syncope in the Emergency Department?

Syncope is a common and challenging presenting complaint to the Emergency Department (ED). Despite substantial research efforts, there is still considerable uncertainty about the optimal ED management of syncope. There is continued interest among clinicians and researchers in improving diagnostic algorithms and optimizing resource utilization. In this paper, we discuss 4 strategies to improve the emergency care of syncope patients: (1) Development of accurate and consistent risk-stratification, (2) Increased use of syncope observation protocols, (3) Evaluation of a discharge with ambulatory monitoring pathway, (4) Use of shared decision-making for disposition decisions. Since current risk-stratification tools have fallen short with regard to subsequent validation and implementation into clinical practice, we outline key factors for future risk-stratification research. We propose that observation units have the potential to safely decrease length-of-stay and hospital costs for hemodynamically stable, intermediate risk patients without adversely affecting clinical outcomes. For appropriate patients with a negative ED evaluation, we recommend consideration of direct discharge, with ambulatory monitoring and expedited follow-up, as a means of decreasing costs and reducing iatrogenic harms. Finally, we advocate for the use of shared decision-making regarding the ultimate disposition of select, intermediate risk patients who have not had a serious condition revealed in the ED. If properly implemented, these four strategies could significantly improve the care of ED syncope patients by helping clinicians identify truly high-risk patients, decreasing unnecessary hospitalizations, and increasing patient satisfaction.

The Reveal LINQ insertable cardiac monitor

Insertable cardiac monitors (ICMs) are leadless subcutaneous devices that continuously monitor the heart rhythm and record events over a timeframe measured in years, allowing for the diagnosis of infrequent rhythm abnormalities that can be the cause of palpitations, syncope and stroke. To date, ICMs have primarily been used in the work-up and management of syncope; however, their use in other areas of rhythm evaluation, particularly atrial fibrillation monitoring, is increasing. The Reveal LINQ™ is the smallest and most versatile ICM available and represents a dramatic leap forward in ICM technology that has the potential to transform patient care in a number of circumstances. Device miniaturization, simplified implant procedure and enhanced automation vastly increase physician and patient acceptance. The next 5 years can be expected to bring a greatly increased use of ICMs for disease diagnosis and management in a variety of clinical settings.

Priorities for emergency department syncope research

STUDY OBJECTIVES

There is limited evidence to guide the emergency department (ED) evaluation and management of syncope. The First International Workshop on Syncope Risk Stratification in the Emergency Department identified key research questions and methodological standards essential to advancing the science of ED-based syncope research.

METHODS

We recruited a multinational panel of syncope experts. A preconference survey identified research priorities, which were refined during and after the conference through an iterative review process.

RESULTS

There were 31 participants from 7 countries who represented 10 clinical and methodological specialties. High-priority research recommendations were organized around a conceptual model of ED decisionmaking for syncope, and they address definition, cohort selection, risk stratification, and management.

CONCLUSION

We convened a multispecialty group of syncope experts to identify the most pressing knowledge gaps and defined a high-priority research agenda to improve the care of patients with syncope in the ED.

Clinical evaluation and risk stratification in patients with syncope

Syncope accounts for approximately 1 % of visits to emergency departments. The first diagnostic step is to rule out nonsyncopal conditions as a cause of the transient loss of consciousness. Next, the basic clinical evaluation should identify patients at high risk for potentially life-threatening events. These patients should be admitted and monitored until a diagnosis is made and definitive treatment can be offered. Guided by the basic evaluation findings, specific tests should be performed to prove or rule out the suspected diagnosis. In low-risk patients, this should preferably be done in an outpatient setting. To date, there is no consensus on a structured algorithm for the evaluation of patients with syncope. Therefore, it seems beneficial to formulate an algorithm based on the current guidelines for the management of syncope for use in the clinical setting.

Cardiac monitoring in patients with syncope: making that elusive diagnosis

Elucidating the cause of syncope is often a diagnostic challenge. At present, there is a myriad of ambulatory cardiac monitoring modalities available for recording cardiac rhythm during spontaneous symptoms. We provide a comprehensive review of these devices and discuss strategies on how to reach the elusive diagnosis based on current evidencebased recommendations.

Clinical utility of implantable loop recorders

Implantable loop recorders provide the highest sensitivity and accuracy of diagnosing cardiac arrhythmia that results in cardiac syncope. When bradyarrhythmia or tachyarrhythmia, including atrial fibrillation, is detected, appropriate secondary prevention therapy will be implemented, which will impact the long-term clinical outcome. An implantable loop recorder enables the clinician to record for a longer period of time, which increases the likelihood of detecting cardiac arrhythmia. Currently, this technology is being evaluated to diagnose a cardiac etiology of ischemic stroke and to optimize atrial fibrillation management that will predict the success of rhythm control and prevent thromboembolic events. This article reviews implantable loop recorder technology, and discusses the current indications, the outcomes of clinical studies and ongoing current studies, and future technological improvements.

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.

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.