Syncope

Trends in syncope testing and admissions in the USA from 2006 through 2019

INTRODUCTION

Syncope is common, with bimodal distribution through life, peaking in adolescence and in the elderly, and overall increases in incidence with age among both men and women. In this context, syncope-related visits to emergency departments (ED), hospitalizations, and testing are a significant healthcare cost burden. Ultimately, understanding the volume of testing types and settings of syncope encounters may aid in more effective healthcare utilization and high value care for this patient population.

METHODS

Data for this study were collected from the Truven Health Analytics MarketScan Database from 2006 to 2019. This database contains both commercially insured patients and those with Medicare coverage. Patients with the diagnosis of syncope were identified using International Classification of Diseases (ICD)-9 and -10 codes. We assessed the incidence of various tests for syncope evaluation and ED disposition for the study period.

RESULTS

The incidence of syncope among the study cohort rose from nine per 1000 patients to 13 per 1000 patients during the study period. The incidence of testing for syncope among multiple domains (neurologic, cardiac, blood testing) decreased in some categories, but routine testing remained prevalent. Women had a significantly lower incidence of testing in most testing domains. Discharge rate from the ED for patients presenting with syncope remained stable during the study period. However, admission rate to the hospital for those aged > 65 years increased during the study time.

CONCLUSION

Testing and admissions for syncope remain prevalent and are drivers of healthcare-associated costs. There is a clear need for further work in developing a focused approach in the evaluation of syncope patients in order to mitigate healthcare costs and improve outcomes.

Evaluation and Management of Acute Transient Loss of Consciousness

Transient loss of consciousness (TLOC) is among the most common complaints encountered by clinicians across specialties. Possible etiologies of acute TLOC can be classified as neurologic, systemic, and functional. Neurologic causes occur due to a primary dysfunction of the neuronal circuitry that maintains awareness, as seen in epileptic seizures. Systemic conditions affect consciousness through global cerebral dysfunction or hypoperfusion with subsequent loss of postural tone through varied mechanisms such as hypoxia, hypoglycemia, and neurocardiogenic syncope. Functional neurologic disorders (also known as conversion disorders or psychogenic spells) refer to clinical conditions in which clinical presentation can mimic but does not completely fit with any specific neurologic or systemic disorder and conventional diagnostic testing reveals normal neurologic and systemic structures. The focus of this review will be on the diagnostic process and tools to differentiate between the multitudes of causes of TLOC.

Unmasking the hidden culprit: Recurrent syncope in a 62-year-old man linked to severe internal carotid artery stenosis

Syncope, a brief loss of consciousness, has many potential causes, with internal carotid artery (ICA) stenosis being a relatively uncommon but serious one. We present the case of a 62-year-old man from Dhaka, Bangladesh, who experienced recurrent syncope over 6 months, characterized by a brief loss of consciousness, occasional dizziness, and blurred vision. Despite a history of hypertension and hyperlipidemia, initial cardiac and neurogenic investigations were inconclusive. Magnetic resonance angiography revealed 90% stenosis of the right ICA, which was confirmed by digital subtraction angiography. The patient was treated with antiplatelet therapy, statins, and antihypertensives, and underwent carotid artery stenting. His postoperative recovery was uneventful, and he remained symptom-free during follow-up. This case underscores the importance of considering ICA stenosis in patients with recurrent syncope and comorbid vascular disease, particularly in resource-limited settings where timely diagnosis and intervention can prevent serious cerebrovascular complications.

Respiratory Syncytial Virus (RSV)-Induced Autoimmune Hemolytic Anemia Presenting as Syncope: A Case Report

Autoimmune hemolytic anemia (AIHA) is a condition that causes an individual's immune system to destroy its own red blood cells. Immune cells are activated against the red blood cell antigens to induce hemolysis. Patients typically present with symptomatic anemia when the extent of hemolysis overcomes the bone marrow's ability to compensate. Steroids are typically the first-line treatment, along with supportive care and blood transfusion for severe anemia. This case report details a patient who had presented to the ED after a syncopal episode that was ultimately due to respiratory syncytial virus (RSV)-induced warm AIHA.

An Efficient Approach to the Inpatient Syncope Workup

This review aims to provide hospitalists with a streamlined understanding of the evaluation of syncope, a commonly encountered complaint in hospital medicine. Authors conducted a literature review using the keyword 'syncope' to compile current evidence and recommendations regarding the categorization, risk stratification, and diagnostic evaluation of syncope. The review outlines the categorization of syncope into cardiac, neurally mediated, and orthostatic types, detailing the clinical features, etiologies, and differential diagnoses of each. It provides a structured framework for history-taking, physical examination, orthostatic vital sign assessment, and risk stratification to guide clinicians in efficiently identifying high-risk patients requiring urgent intervention. Additionally, diagnostic modalities including electrocardiography, echocardiography, and point-of-care ultrasound are discussed, along with their respective indications and limitations. By embracing standardized approaches and evidence-based practices outlined in this review, hospitalists can optimize resource utilization, streamline patient care, and improve outcomes in patients presenting with syncope.

Lifestyle Effects on an Unusual Presentation of Syncope: A Case Report

We present a 53-year-old Hispanic male with a history of palpitations and chronic marijuana use coming to the emergency department (ED) with three episodes of sudden loss of consciousness that occurred after starting his job as a night shift worker, which led to severe chronic sleep deprivation. These episodes lacked prodromal (chest pain, shortness of breath, palpitations, diaphoresis) and postictal (drowsiness, nausea, confusion, headache) symptoms. Electrocardiograms (EKGs) performed in the ED revealed sinus bradycardia with a heart rate of 54 beats per minute (bpm), which dropped to 37 bpm during admission. Overnight telemetry exhibited sinus pauses, characterized by a delay in atrial activity for at least three seconds. A repeat EKG showed an incomplete right bundle branch block (RBBB). The patient received a final diagnosis of recurrent syncope and was given an implantable loop recorder (ILR). The ILR revealed several sinus pauses over the span of three months with no syncopal episodes. The patient was educated on dietary and lifestyle modifications to reduce the risk of experiencing syncopal episodes. This case study explores a unique presentation of syncope with a multifactorial etiology and discusses the impact of lifestyle behaviors on syncope exacerbation.

The syncope core management process in the emergency department: a consensus statement of the EUSEM syncope group

The European Society of Cardiology issued updated syncope guidelines in 2018 which included recommendations for managing syncope in the emergency department (ED) setting. However, these guidelines lack detailed process-oriented instructions regarding the fact that ED syncope patients initially present with a transient loss of consciousness (TLOC), which can have a broad spectrum of causes. This study aims to establish a European consensus on the general process of the workup and care for patients with suspected syncope and provides rules for sufficient and systematic management of the broad group of syncope (initially presenting as TLOC) patients in the ED. A variety of European diagnostic and therapeutic standards for syncope patients were reviewed and summarized in three rounds of a modified Delphi process by the European Society for Emergency Medicine syncope group. Based on a consensus statement, a detailed process pathway is created. The primary outcome of this work is the presentation of a universal process pathway for the structured management of syncope patients in European EDs. The here presented extended event process chain (eEPC) summarizes and homogenizes the process management of European ED syncope patients. Additionally, an exemplary translation of the eEPC into a practice-based flowchart algorithm, which can be used as an example for practical use in the ED, is provided in this work. Syncope patients, initially presenting with TLOC, are common and pose challenges in the ED. Despite variations in process management across Europe, the development of a universally applicable syncope eEPC in the ED was successfully achieved. Key features of the consensus and eEPC include ruling out life-threatening causes, distinguishing syncope from nonsyncopal TLOCs, employing syncope risk stratification categories and based on this, making informed decisions regarding admission or discharge.

Frequency of Electrocardiogram-Defined Cardiac Conduction Disorders in a Multi-Institutional Primary Care Cohort

Background

Disorders affecting cardiac conduction are associated with substantial morbidity. Understanding the epidemiology and risk factors for conduction disorders may enable earlier diagnosis and preventive efforts.

Objectives

The purpose of this study was to quantify contemporary frequency and risk factors for electrocardiogram (ECG)-defined cardiac conduction disorders in a large multi-institutional primary care sample.

Methods

We quantified prevalence and incidence of conduction disorders among adults receiving longitudinal primary care between 2001 and 2019, each with at least one 12-lead ECG performed prior to the start of follow-up and at least one ECG during follow-up. We defined conduction disorders using curated terms extracted from ECG diagnostic statements by cardiologists. We grouped conduction disorders by inferred anatomic location of abnormal conduction. We tested associations between clinical factors and incident conduction disease using multivariable proportional hazards regression.

Results

We analyzed 189,163 individuals (median age 55 years; 58% female). The overall prevalence of conduction disorders was 27% among men and 15% among women. Among 119,926 individuals (median age 55 years; 51% female), 6,802 developed an incident conduction system abnormality over a median of 10 years (Q1, Q3: 6, 15 years) of follow-up. Incident conduction disorders were more common in men (8.78 events/1,000 person-years) vs women (4.34 events/1,000 person-years, P < 0.05). In multivariable models, clinical factors including older age (HR: 1.25 per 5-year increase [95% CI: 1.24-1.26]) and myocardial infarction (HR: 1.39 [95% CI: 1.26-1.54]) were associated with incident conduction disorders.

Conclusions

Cardiac conduction disorders are common in a primary care population, especially among older individuals with cardiovascular risk factors.

Therapeutic options for neurocardiogenic syncope: a meta-analysis of randomised trials with and without blinding

BACKGROUND

Neurocardiogenic syncope is a common condition with significant associated psychological and physical morbidity. The effectiveness of therapeutic options for neurocardiogenic syncope beyond placebo remains uncertain.

METHODS

The primary endpoint was the risk ratio (RR) of spontaneously recurring syncope following any therapeutic intervention. We also examined the effect of blinding on treatment efficacy. We identified all randomised trials which evaluated the effect of any pharmacological, device-based or supportive intervention on patients with a history of syncope. A systematic search was conducted on Medline, Embase, PubMed databases and Cochrane Central Register for Controlled Trials from 1950 to 25 April 2023. Event rates, their RRs and 95% CIs were calculated, and a random-effects meta-analysis was conducted for each intervention. Data analysis was performed in R using RStudio.

RESULTS

We identified 47 eligible trials randomising 3518 patients. Blinded trials assessing syncope recurrence were neutral for beta blockers, fludrocortisone and conventional dual-chamber pacing but were favourable for selective serotonin reuptake inhibitors (SSRIs) (RR 0.40, 95% CI 0.26 to 0.63, p<0.001), midodrine (RR 0.70, 95% CI 0.53 to 0.94, p=0.016) and closed-loop stimulation (CLS) pacing (RR 0.15, 95% CI 0.07 to 0.35, p<0.001). Unblinded trials reported significant benefits for all therapy categories other than beta blockers and consistently showed larger benefits than blinded trials.

CONCLUSIONS

Under blinded conditions, SSRIs, midodrine and CLS pacing significantly reduced syncope recurrence. Future trials for syncope should be blinded to avoid overestimating treatment effects.

PROSPERO REGISTRATION NUMBER

CRD42022330148.

[Syncopes - differential diagnoses and treatment]

Syncope is a sudden loss of consciousness (transient loss of consciousness, TLOC) caused by a lack of cerebral perfusion that resolves spontaneously and completely after a short period of time 1. With a lifetime prevalence of 40% and constituting about 1% of all emergency department admissions, syncope is a common and medically relevant problem 2 3. The underlying causes of syncope are diverse and associated with significantly different prognoses. A structured approach is essential to identify high-risk patients and ensure appropriate treatment. This article aims at providing an overview of the current recommendations for the diagnosis and treatment of syncope.

Unraveling Wavy ST Segments-An Unusual Case of Syncope

This case report describes a patient in their 60s with gastroesophageal reflex disease who presented to the emergency department after loss of consciousness during dinner and daily intermittent chest discomfort.

New-onset syncope in diabetic patients treated with sodium-glucose cotransporter-2 inhibitors versus dipeptidyl peptidase-4 inhibitors: a Chinese population-based cohort study

BACKGROUND AND AIMS

Syncope is a symptom that poses an important diagnostic and therapeutic challenge, and generates significant cost for the healthcare system. Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have demonstrated beneficial cardiovascular effects, but their possible effects on incident syncope have not been fully investigated. This study compared the effects of SGLT2i and dipeptidyl peptidase-4 inhibitors (DPP4i) on new-onset syncope.

METHODS AND RESULTS

This was a retrospective, territory-wide cohort study enrolling type 2 diabetes mellitus (T2DM) patients treated with SGLT2i or DPP4i between 1 January 2015 and 31 December 2020, in Hong Kong, China. The outcomes were hospitalization of new-onset syncope, cardiovascular mortality, and all-cause mortality. Multivariable Cox regression and different approaches using the propensity score were applied to evaluate the association between SGLT2i and DPP4i with incident syncope and mortality. After matching, a total of 37 502 patients with T2DM were included (18 751 SGLT2i users vs. 18 751 DPP4i users). During a median follow-up of 5.56 years, 907 patients were hospitalized for new-onset syncope (2.41%), and 2346 patients died from any cause (6.26%), among which 471 deaths (1.26%) were associated with cardiovascular causes. Compared with DPP4i users, SGLT2i therapy was associated with a 51% lower risk of new-onset syncope [HR 0.49; 95% confidence interval (CI) 0.41-0.57; P < 0.001], 65% lower risk of cardiovascular mortality (HR 0.35; 95% CI 0.26-0.46; P < 0.001), and a 70% lower risk of all-cause mortality (HR 0.30; 95% CI 0.26-0.34; P < 0.001) in the fully adjusted model. Similar associations with syncope were observed for dapagliflozin (HR 0.70; 95% CI 0.58-0.85; P < 0.001), canagliflozin (HR 0.48; 95% CI 0.36-0.63; P < 0.001), and ertugliflozin (HR 0.45; 95% CI 0.30-0.68; P < 0.001), but were attenuated for empagliflozin (HR 0.79; 95% CI 0.59-1.05; P = 0.100) after adjusting for potential confounders. The subgroup analyses suggested that, compared with DPP4i, SGLT2i was associated with a significantly decreased risk of incident syncope among T2DM patients, regardless of gender, age, glucose control status, Charlson comorbidity index, and the association remained constant amongst those with common cardiovascular drugs and most antidiabetic drugs at baseline.

CONCLUSION

Compared with DPP4i, SGLT2i was associated with a significantly lower risk of new-onset syncope in patients with T2DM, regardless of gender, age, degree of glycaemic control, and comorbidity burden.

Vestibular syncope

PURPOSE OF REVIEW

This review considers recent observations on vestibular syncope in terms of clinical features, laboratory findings, and potential mechanisms.

RECENT FINDINGS

Vestibular syncope, potentially associated with severe fall-related injuries, may develop multiple times in about one-third of patients. Meniere's disease and benign paroxysmal positional vertigo are the most common causes of vestibular syncope, but the underlying disorders remain elusive in 62% of cases with vestibular syncope. The postictal orthostatic blood pressure test exhibits a lower diagnostic yield. Vestibular function tests, such as cervical vestibular-evoked myogenic potentials and video head impulse tests, can reveal one or more abnormal findings, suggesting compensated or ongoing minor vestibular dysfunctions. The pathomechanism of syncope is assumed to be the erroneous interaction between the vestibulo-sympathetic reflex and the baroreflex that have different operating mechanisms and action latencies. The central vestibular system, which estimates gravity orientation and inertia motion may also play an important role in abnormal vestibulo-sympathetic reflex.

SUMMARY

Vestibular disorders elicit erroneous cardiovascular responses by providing false vestibular information. The results include vertigo-induced hypertension or hypotension, which can ultimately lead to syncope in susceptible patients.

Recent Advances and Future Directions in Syncope Management: A Comprehensive Narrative Review

Syncope is a highly prevalent clinical condition characterized by a rapid, complete, and brief loss of consciousness, followed by full recovery caused by cerebral hypoperfusion. This symptom carries significance, as its potential underlying causes may involve the heart, blood pressure, or brain, leading to a spectrum of consequences, from sudden death to compromised quality of life. Various factors contribute to syncope, and adhering to a precise diagnostic pathway can enhance diagnostic accuracy and treatment effectiveness. A standardized initial assessment, risk stratification, and appropriate test identification facilitate determining the underlying cause in the majority of cases. New technologies, including artificial intelligence and smart devices, may have the potential to reshape syncope management into a proactive, personalized, and data-centric model, ultimately enhancing patient outcomes and quality of life. This review addresses key aspects of syncope management, including pathogenesis, current diagnostic testing options, treatments, and considerations in the geriatric population.

Syncope with autonomic dysfunction assessed with the Thai-COMPASS 31 questionnaire

Introduction

Alteration of autonomic function is the main pathophysiology of most types of syncope, including syncope due to orthostatic hypotension and neurally mediated syncope or reflex syncope. The aim of this study was to investigate the difference in autonomic dysfunction assessed between each type of syncope and to evaluate the association between the severity of autonomic dysfunction and the recurrence of syncope.

Methodology

Three hundred and six participants, including 195 syncope and 109 healthy control participants, were recruited to this retrospective cohort study. Autonomic function was initially assessed by the Thai version of the Composite Autonomic Symptom Score 31 (COMPASS 31), a self-administered questionnaire.

Result

According to one hundred and ninety-five syncope participants, twenty-three participants had syncope due to orthostatic hypotension, 61 had reflex syncope, 79 had presyncope, and 32 had unclassified syncope. Participants in the syncope due to orthostatic hypotension and reflex syncope groups had significantly higher COMPASS 31 scores than the control and presyncope groups, of which the syncope due to orthostatic hypotension group had the highest score. The cutoff score of 32.9 for COMPASS 31 had a sensitivity of 50.0% and a specificity of 81.9% to predict the recurrence of syncope.

Conclusion

The degree of autonomic dysfunction, which was assessed by COMPASS 31, could vary depending on the syncope type. The COMPASS 31, which is an easy-to-use self-administered questionnaire utilized for the assessment of autonomic symptoms and function, was a helpful tool for classifying some types of syncope and predicting the recurrence of syncope, which could lead to appropriate further management.

State of the Art and Challenges in Epilepsy—A Narrative Review

Epilepsy is a common condition worldwide, with approximately 50 million people suffering from it. A single seizure does not mean epilepsy; almost 10% of the population can have a seizure during their lifetime. In particular, there are many other central nervous system disorders other than epilepsy in which seizures occur, either transiently or as a comorbid condition. The impact of seizures and epilepsy is, therefore, widespread and easily underestimated. It is estimated that about 70% of patients with epilepsy could be seizure-free if correctly diagnosed and treated. However, for patients with epilepsy, quality of life is influenced not only by seizure control but also by antiepileptic drug-adverse reactions, access to education, mood, employment, and transportation.

Syncope Diagnosis at Referral to a Tertiary Syncope Unit: An in-Depth Analysis of the FAST II

OBJECTIVE

A substantial number of patients with a transient loss of consciousness (T-LOC) are referred to a tertiary syncope unit without a diagnosis. This study investigates the final diagnoses reached in patients who, on referral, were undiagnosed or inaccurately diagnosed in secondary care.

METHODS

This study is an in-depth analysis of the recently published Fainting Assessment Study II, a prospective cohort study in a tertiary syncope unit. The diagnosis at the tertiary syncope unit was established after history taking (phase 1), following autonomic function tests (phase 2), and confirming after critical follow-up of 1.5-2 years, with the adjudicated diagnosis (phase 3) by a multidisciplinary committee. Diagnoses suggested by the referring physician were considered the phase 0 diagnosis. We determined the accuracy of the phase 0 diagnosis by comparing this with the phase 3 diagnosis.

RESULTS

51% (134/264) of patients had no diagnosis upon referral (phase 0), the remaining 49% (130/264) carried a diagnosis, but 80% (104/130) considered their condition unexplained. Of the patients undiagnosed at referral, three major causes of T-LOC were revealed: reflex syncope (69%), initial orthostatic hypotension (20%) and psychogenic pseudosyncope (13%) (sum > 100% due to cases with multiple causes). Referral diagnoses were either inaccurate or incomplete in 65% of the patients and were mainly altered at tertiary care assessment to reflex syncope, initial orthostatic hypotension or psychogenic pseudosyncope. A diagnosis of cardiac syncope at referral proved wrong in 17/18 patients.

CONCLUSIONS

Syncope patients diagnosed or undiagnosed in primary and secondary care and referred to a syncope unit mostly suffer from reflex syncope, initial orthostatic hypotension or psychogenic pseudosyncope. These causes of T-LOC do not necessarily require ancillary tests, but can be diagnosed by careful history-taking. Besides access to a network of specialized syncope units, simple interventions, such as guideline-based structured evaluation, proper risk-stratification and critical follow-up may reduce diagnostic delay and improve diagnostic accuracy for syncope.

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.

Vestibular syncope: clinical characteristics and mechanism

Background and Objectives

Vestibular syncope is a condition in which vertigo‐induced hemodynamic changes cause syncope. This study investigated the clinical and laboratory findings of vestibular syncope and tried to refine our knowledge of the mechanism underlying this newly recognized entity.

Methods

This study retrospectively analyzed 53 patients (33 women, median age = 63 years [interquartile range = 54–71 years]) with vestibular syncope from January 2017 to December 2021. To explain the mechanism of vestibular syncope, we incorporated a velocity‐storage model into the dual reflex pathways comprising the vestibulo‐sympathetic reflex and baroreflex and predicted the cardiovascular responses.

Results

Twenty (37.7%) patients had multiple episodes of vestibular syncope, and seven (13.2%) had potentially life‐threatening injuries. Meniere's disease (20.8%) and benign paroxysmal positional vertigo (9.4%) were the most common underlying vestibular disorders. Abnormal vestibular function tests included impaired cervical vestibular‐evoked myogenic potentials (57.5%) and positive head impulse tests (31.0%). Orthostatic hypotension was found in 19.5% of patients. Dyslipidemia (30.2%) and hypertension (28.3%) were common medical comorbidities. The dual reflex pathways incorporating the function of the velocity‐storage circuit in the brainstem and cerebellum suggest that vestibular syncope is a neurally mediated reflex syncope associated with a sudden hemodynamic change during vertigo. This change can be arterial hypertension triggered by a false downward inertial cue, as suggested previously, or hypotension driven by a false upward inertial cue.

Conclusions

Vestibular syncope is associated with various vestibular disorders and requires careful evaluation and intervention to prevent recurrent falls and significant injuries.

The Syncopal Sarcoma

Primary cardiac synovial sarcomas are very rare, representing <1% of all primary cardiac tumors. We report the case of a 19-year-old man with syncope and dynamic obstructive shock caused by a large right-sided intracardiac tumor. (Level of Difficulty:Beginner.)

Appropriate use of transthoracic echocardiography in the investigation of general medicine patients presenting with syncope or presyncope

STUDY PURPOSE

Routine transthoracic echocardiography (TTE) in patients with syncope or presyncope is resource-intensive. We assessed if risk thresholds defined by a validated risk score may identify patients at low risk of cardiac abnormality in whom TTE is unnecessary.

STUDY DESIGN

We conducted a retrospective study of all general medicine patients with syncope/presyncope presenting to a tertiary hospital between July 2016 and September 2020 and who underwent TTE. The Canadian Syncope Risk Score (CSRS) was used to categorise patients as low to very low risk (score -3 to 0) or moderate to high risk (score ≥1) for serious adverse events at 30 days. A cut-point of 0 was used to calculate the sensitivity, specificity, positive and negative predictive values (PPV and NPV) for CSRS and the odds ratio (OR) of a clinically significant finding on TTE in patients with CSRS ≥1 compared with all patients.

RESULTS

Among 157 patients, the CSRS categorised 69 (44%) as very low to low risk in whom TTE was normal. In 88 patients deemed moderate to high risk, TTE detected a cardiac abnormality in 24 (27%). A CSRS ≥1 yielded a sensitivity of 100% (95% CI 85.7% to 100%), specificity of 51.1% (95% CI 42.3% to 59.8%), PPV of 26.5% (95% CI 26.3% to 30.1%) and NPV of 100% (95% CI 92.5% to 100%) for cardiac abnormalities and doubled the odds of an abnormality (OR=2.05, 95% CI 1.08 to 3.87, p=0.028).

CONCLUSION

In general medicine patients with syncope/presyncope, using the CSRS to stratify risk of a cardiac abnormality on TTE can almost halve TTE use.

Prenatal exercise and cardiovascular health (PEACH) study: impact of acute and chronic exercise on cerebrovascular hemodynamics and dynamic cerebral autoregulation

We performed a randomised controlled trial measuring dynamic cerebral autoregulation (dCA) using a sit-to-stand maneuver before (SS1) and following (SS2) an acute exercise test at 16-20 weeks gestation (trimester 2; TM2) and then again at 34-37 weeks gestation (third trimester; TM3). Following the first assessment, women were randomised into exercise training or control (standard care) groups; women in the exercise training group were prescribed moderate intensity aerobic exercise for 25-40 minutes on 3-4 days per week for 14±1weeks. Resting seated mean blood velocity in the middle cerebral artery (MCAv_mean) was lower in TM3 compared to TM2 but not impacted by exercise training intervention. dCA was not impacted by gestational age, or exercise training during SS1. During SS2, dCA was altered such that there were greater absolute and relative decreases in mean arterial blood pressure (MAP) and MCAv_mean, but this was not impacted by the intervention. There was also no difference in the relationship between the decrease in MCAv_mean compared to the decrease in MAP (%/%), or the onset of the regulatory response with respect to acute exercise, gestational age, or intervention; however, rate of regulation was faster in women in the exercise group following acute exercise (interaction effect, p=0.048). These data highlight the resilience of the cerebral circulation in that dCA was well maintained or improved in healthy pregnant women between TM2 and TM3. However, future work addressing the impact of acute and chronic exercise on dCA in women who are at risk for cardiovascular complications during pregnancy is needed.

Midodrine for the Prevention of Vasovagal Syncope : A Randomized Clinical Trial

BACKGROUND

Recurrent vasovagal syncope is common, responds poorly to treatment, and causes physical trauma and poor quality of life. Midodrine prevents hypotension and syncope during tilt tests in patients with vasovagal syncope.

OBJECTIVE

To determine whether midodrine can prevent vasovagal syncope in usual clinical conditions.

DESIGN

Randomized, double-blind, placebo-controlled clinical trial. (ClinicalTrials.gov: NCT01456481).

SETTING

25 university hospitals in Canada, the United States, Mexico, and the United Kingdom.

PATIENTS

Patients with recurrent vasovagal syncope and no serious comorbid conditions.

INTERVENTION

Patients were randomly assigned 1:1 to placebo or midodrine and followed for 12 months.

MEASUREMENTS

The primary outcome measure was the proportion of patients with at least 1 syncope episode during follow-up.

RESULTS

The study included 133 patients who had had a median of 6 syncope episodes in the prior year (median age, 32 years; 73% female). Compared with patients receiving placebo, fewer patients receiving midodrine had at least 1 syncope episode (28 of 66 [42%] vs. 41 of 67 [61%]). The relative risk was 0.69 (95% CI, 0.49 to 0.97; P = 0.035). The absolute risk reduction was 19 percentage points (CI, 2 to 36 percentage points), and the number needed to treat to prevent 1 patient from having syncope was 5.3 (CI, 2.8 to 47.6). The time to first syncope was longer with midodrine (hazard ratio, 0.59 [CI, 0.37 to 0.96]; P = 0.035; log-rank P = 0.031). Adverse effects were similar in both groups.

LIMITATION

Small study size, young and healthy patients, relatively short observation period, and high proportion of patients from 1 center.

CONCLUSION

Midodrine can reduce the recurrence of syncope in healthy, younger patients with a high syncope burden.

PRIMARY FUNDING SOURCE

The Canadian Institutes of Health Research.

Clinical Significance of the Head-Up Tilt Test in Improving Prognosis in Patients with Possible Neurally Mediated Syncope

Simple Summary

Several diseases can cause syncope, which is commonly known as fainting; however, syncope triggered by a reflex mechanism, also termed neurally mediated syncope (NMS), is one of the most common forms. While NMS is considered a benign disease, it can cause critical clinical events, such as severe trauma due to syncope. The head-up tilt test (HUTT) is one of the modalities for the diagnosis of NMS. The clinical significance of HUTT in the prognosis of NMS, such as recurrence rate of syncope and mortality, are still to be elucidated. This research aimed to clarify the value of HUTT for the diagnosis of NMS, and to investigate the prognosis of patients with NMS by analyzing the data of 101 patients with syncope and their close long-term (four years at the longest) follow-up. Furthermore, as insertable cardiac monitors (ICMs) are considered effective in patients with syncope, this study also aimed to evaluate the usefulness of ICM in patients with negative HUTT results. Finally, our research contributes to the improvement of the clinical management for patients with syncope.

Abstract

Syncope is commonly encountered in daily clinical practice. Depending on its etiology (benign or life-threatening conditions or environmental triggers), syncope can be neurally mediated (reflex), cardiac, or orthostatic. Furthermore, neurologic disease can cause symptoms that mimic syncope. However, there is limited research on neurally mediated syncope (NMS), which is considered a benign disorder, and close follow-ups are rarely performed. NMS can cause serious clinical events, including severe trauma and car accidents. The head-up tilt test (HUTT) is the gold standard for diagnosing NMS; however, its clinical significance remains unknown, and its relevance to NMS prognosis requires further research. This retrospective study aimed to assess the clinical significance of the HUTT for NMS. We reviewed the charts of 101 patients who underwent HUTT at Tokai University Hospital in Japan between January 2016 and March 2019. During the HUTT, 72 patients (69.2%) experienced syncope. Patients were followed up for 886.1 ± 457.7 days (interquartile range: 518–1293 days). The syncope recurrence rate was 16.9%; however, no significant difference was observed between the two groups (HUTT positive vs. negative) (13.8% vs. 18.1%, p = 0.772). Four of 29 (13.9%) and two of 72 (2.8%) patients in the negative and positive HUTT groups, respectively, experienced cardiac events (p = 0.019). Negative HUTT results may assist in anticipating unexpected clinical events within a few years. A negative HUTT result may allow us to reconsider the NMS diagnosis based on clinical information. Close outpatient follow-up of patients with negative HUTT results is warranted.

Syncope associated with supraventricular tachycardia: Diagnostic role of implantable loop recorders

Syncope represents a relatively uncommon symptom of supraventricular tachycardia (SVT). It is likely that an impaired autonomic vasomotor response to the hemodynamic stress of tachycardia is the determinant of hemodynamic changes leading to cerebral hypoperfusion and syncope. In this regard, tilt-table test may detect abnormalities in the autonomic nervous function and predict the occurrence of syncope during SVT. Electrophysiology studies may reproduce the SVT, distinguish it from other life-threatening ventricular tachyarrhythmias, and exclude other causes of syncope. Not infrequently mixed syncope mechanisms are revealed during the above diagnostic workup raising doubts about the operating mechanism in the clinical setting. In such cases of uncertainty, an implantable loop recorder, providing long-term cardiac monitoring, may play a pivotal role in the establishment of the diagnosis, confirming the association of an arrhythmic event with the symptom. Herein, we present four such cases with recurrent unexplained syncope finally attributed to paroxysmal SVT guiding them to a potentially radical treatment through radiofrequency catheter ablation.

Diagnosis and prevention of the vasodepressor type of neurally mediated syncope in Japanese patients

We investigated circulatory dynamics in patients with vasodepressor type neurally mediated syncope (VT-NMS) by performing high-resolution Holter electrocardiography and a correlation analysis of changes in adenylate cyclase activity, blood pressure, and pulse during the head-up tilt test. Holter electrocardiography was performed for 30 patients. Adenylate cyclase activity was evaluated in lymphocytes from blood samples taken at rest and during the head-up tilt test. There was no change in autonomic nerve fluctuation during electrocardiography in VT-NMS patients, but our results showed a significant difference in blood pressure and adenylate cyclase activity between VT-NMS patients and healthy volunteers; the systolic blood pressure of VT-NMS patients decreased after 5 min, while at 10 min, the adenylate cyclase activity was the highest (0.53%) and the systolic blood pressure was the lowest (111.8 mm Hg). Pulse rates increased after 10 min. VT-NMS patients showed higher blood pressure, pulse rate, and adenylate cyclase activity during the tilt test than did healthy volunteers. In patients with syncope, standing for longer than 10 minutes may increase the risk of VT-NMS. From our results, we consider it likely that high systolic blood pressure and adenylate cyclase activity at rest cause fainting in VT-NMS patients. Our findings may be helpful for identifying individuals with a high risk of developing NMS in the healthy population.

Arrhythmogenic Right Ventricular Cardiomyopathy as a Cause of Palpitations and Syncope in an Otherwise Healthy Active Duty Female

Identifying the cause of palpitations and syncope in the healthy, active duty military population is important. Most often, the causes are benign, but more malignant etiologies should not be overlooked. In this case, we present a 22-year-old active duty female soldier who developed exercise intolerance, palpitations, and ultimately one episode of exercise-induced syncope. Outpatient evaluation with Holter monitor revealed sustained ventricular tachycardia while exercising. Electrocardiogram revealed findings concerning for arrhythmogenic right ventricular cardiomyopathy based on the 2010 Revised Task Force Criteria. Further investigation with cardiac magnetic resonance imaging helped confirm the diagnosis. Sotalol was used as an antiarrhythmic therapy and an automatic implantable cardioverter defibrillator was implanted to reduce the risk of sudden cardiac death. This case represents an uncommon cause of palpitations and syncope. Arrhythmogenic right ventricular cardiomyopathy should be on the differential diagnosis in the active duty population who present with exercise-induced syncope.

Trends in use of echocardiography in hospitalized patients with syncope

PURPOSE

We sought to assess the trends in use, predictors of echocardiography, and its impact on in-hospital mortality in patients admitted with syncope using a large national database.

METHODS

Utilizing the Nationwide Inpatient Sample (NIS) database from 2001 to 2014, we identified adult patients (>18 years) with a primary discharge diagnosis of syncope and use of echocardiogram was ascertained.

RESULTS

A total of 3 174 619 patients with a primary discharge diagnosis of syncope were identified, of which 184 167 (5.8%) underwent an echocardiogram. The rate of syncope hospitalization remained constant between 2001 and 2009 (1.1/1000 US population) but has since decreased steadily to about 0.5/1000 US population in 2014. After adjusting for patient and hospital characteristics, the rate of echocardiogram use increased significantly from 5.1% in 2001 to 6.8% in 2014 (2.7% relative increase per year [P_trend  = 0.024]). Predictors of use were cardiac disorders, hypertension, diabetes, peripheral vascular disease, and renal failure. After adjusting for baseline risk, use of echocardiography was not associated with in-hospital mortality (OR = 0.827, P = 0.155), but was associated with a 14.6% increase in adjusted length of stay and a 22.6% increase in adjusted hospital cost compared to no echocardiography use (both P < 0.001).

CONCLUSIONS

The admission rates for syncope are decreasing and use of echocardiography in hospitalized patients with syncope is appropriately low. Given the lack of any favorable impact on mortality and the association with increased costs, there is a continued need to emphasize evidence-based use of echocardiography in patients presenting with syncope.

Utilization of Echocardiogram, Carotid Ultrasound, and Cranial Imaging in the Inpatient Investigation of Syncope: Its Impact on the Diagnosis and the Patient's Length of Hospitalization

Background

Although guidelines suggest that the best strategy for evaluating syncope is clinical history and physical examination, the inappropriate utilization of diagnostic imaging is common.

Methods

A single center retrospective analysis conducted in adult patients admitted for evaluation and management of syncope for a period of 12 months. Charts were reviewed to abstract demographic data, admitting and discharge diagnosis, diagnostic investigatory tests including imaging modalities (echocardiogram, carotid ultrasound, and cranial computed tomography (CT)) ordered, subspecialty consultation requested, treatment rendered and hospital length of stay (LOS).

Results

A total of 109 patients were admitted for syncope, mean age was 68.74 ± 21.04 years and 39.44% were men. Echocardiogram, carotid ultrasound, and cranial CT were ordered in 69.72%, 33.02%, and 76.14% respectively. The mean hospital LOS was 2.6 days. Patients with no imaging test, one imaging test, two imaging tests, and three imaging tests ordered have an average hospital LOS of 2.22 days, 2.44 days, 2.58 days, and 3.07 days respectively. The number of imaging test and its relation to the admitting (Chi-square (chi-sq) P = 0.4165, nominal logistic regression (LR) P = 0.939) and discharge (chi-sq P = 0.1507, nominal LR P = 0.782) diagnosis as well as the LOS in relation to the number of imaging test ordered (analysis of variance (ANOVA) P = 0.368, Kruskal Wallis (KW) P = 0.352) were not statistically significant although there was a trend of prolonged hospital LOS the more imaging diagnostic test had been ordered. Syncope was the admitting and discharge diagnosis in 89.9% and 91.74% respectively.

Conclusions

Choosing the appropriate diagnostic tests as dictated by the patient’s clinical manifestation and utilizing less expensive test would be appropriate and cost-effective approach in appraising patients with syncope.

Trends of hospitalizations for syncope/collapse in the United States from 2004 to 2013-An analysis of national inpatient sample

INTRODUCTION

Syncope/collapse is a common reason for emergency department visits, and approximately 30-40% of these individuals are hospitalized. We examined changes in hospitalization rates, in-hospital mortality, and cost of syncope/collapse-related hospital care in the United States from 2004 to 2013.

METHODS

We used the US Nationwide Inpatient Sample (NIS) from 2004 to 2013 to identify syncope/collapse-related hospitalizations using ICD-9, code 780.2, as the principal discharge diagnosis. Data are presented as mean ± SEM.

RESULTS

From 2004 to 2013, there was a 42% reduction in hospitalizations with a principal discharge diagnosis of syncope/collapse from 54,259 (national estimate 253,591) in 2004 to 31,427 (national estimate 156,820) in 2013 (P < 0.0001). The mean length of hospital stays decreased (2.88 ± 0.04 days in 2004 vs. 2.54 ± 0.02 in 2013; P < 0.0001), while in-hospital mortality did not change (0.28% in 2004 vs. 0.18% in 2013; P  =  0.12). However, mean charges (inflation adjusted) for syncope/collapse-related hospitalization increased by 43.6% from $17,514 in 2004 to $25,160 in 2013 (P < 0.0001). The rates of implantation of permanent pacemakers and implantable cardioverter defibrillator remained low during these hospitalizations, and decreased over time (P for both < 0.0001).

CONCLUSIONS

Hospitalization rates for syncope/collapse have decreased significantly in the US from 2004 to 2013. Despite a modest reduction in length of stay, the cost of syncope/collapse-related hospital care has increased.

The incidence of acute pulmonary embolism following syncope in anticoagulant-naïve patients: A retrospective cohort study

BACKGROUND

A recently published, large prospective study showed unexpectedly high prevalence of acute pulmonary embolism (APE) among patients hospitalized for syncope. In such a case, a high incidence of recurrent pulmonary embolism is expected among patients who were discharged without APE workup.

OBJECTIVES

To determine the incidence of symptomatic APE among patients hospitalized for a first episode of syncope and discharged without APE workup or anticoagulation.

METHODS

This retrospective cohort study included patients hospitalized at Rambam Health Care Campus between January 2006 and February 2017 with a primary admission diagnosis of syncope, who were not investigated for APE and were not taking anticoagulants. The patients were followed up for up to three years after discharge. The occurrence of venous thromboembolism (VTE) during the follow-up period was documented.

RESULTS

The median follow-up duration was 33 months. 1,126 subjects completed a three-year follow-up. During this period, 38 patients (3.38%) developed VTE, 17 (1.51%) of them had APE. The cumulative incidence of VTE and APE was 1.9% (95% CI 1.3%-2.5%) and 0.9% (95% CI 0.4%-1.3%) respectively. Only seven subjects developed APE during the first year of follow-up. The median times from the event of syncope to the development of APE and VTE were 18 and 19 months respectively.

CONCLUSIONS

The cumulative incidence of VTE during a three-year follow-up period after an episode of syncope is low. In the absence of clinical suspicion, a routine diagnostic workup for APE in patients with syncope cannot be recommended.

A Population-Based Study of Syncope in the Young

BACKGROUND

The prevalence, hospitalization patterns, and outcomes of pediatric and adolescent syncope have not been rigorously characterized.

METHODS

Patients < 20 years presenting to an emergency department (ED) with a primary diagnosis of syncope (International Classification of Diseases, 10th revision, code R55) between fiscal year (FY) 2006/2007 and FY 2013/2014 in the province of Alberta, Canada were grouped according to discharge status from the ED, ie, (1) admitted to hospital and (2) discharged without admission. Temporal trends and differences in baseline characteristics, medication use, and outcomes between admitted and discharged patients were examined.

RESULTS

The prevalence of syncope increased from 143/100,000 population in FY 2006/2007 to 166/100,000 population in FY 2013/2014 (P < 0.01). The majority of the 11,488 patients who presented to the ED with syncope were discharged home (n = 11,214 [98%]). Cardiac disease was present in 12.7% and thoracic conditions were present in 8% of the study population. A majority of patients (66.2% admitted and 56.4% discharged; P = 0.018) were taking a prescription drug in the year before presentation. By 30 days, 26.1% of admitted patients had a second ED presentation and 8.1% had a rehospitalization. Among discharged patients, the 30-day repeated ED presentation rate was 11.7% and the hospitalization rate was 1.1%. By 1 year, the rates of repeated ED visits increased to 64.1% and 47.5%, and rehospitalization rates increased to 21.4% and 6.8% among admitted and discharged patients, respectively.

CONCLUSIONS

Our data suggest that pediatric and adolescent syncope is increasing in prevalence and represents a growing public health problem. This population has a high burden of comorbidities that likely contribute to increased health care resource use and polypharmacy.

Prohormones in the Early Diagnosis of Cardiac Syncope

Background

The early detection of cardiac syncope is challenging. We aimed to evaluate the diagnostic value of 4 novel prohormones, quantifying different neurohumoral pathways, possibly involved in the pathophysiological features of cardiac syncope: midregional–pro‐A‐type natriuretic peptide (MRproANP), C‐terminal proendothelin 1, copeptin, and midregional‐proadrenomedullin.

Methods and Results

We prospectively enrolled unselected patients presenting with syncope to the emergency department (ED) in a diagnostic multicenter study. ED probability of cardiac syncope was quantified by the treating ED physician using a visual analogue scale. Prohormones were measured in a blinded manner. Two independent cardiologists adjudicated the final diagnosis on the basis of all clinical information, including 1‐year follow‐up. Among 689 patients, cardiac syncope was the adjudicated final diagnosis in 125 (18%). Plasma concentrations of MRproANP, C‐terminal proendothelin 1, copeptin, and midregional‐proadrenomedullin were all significantly higher in patients with cardiac syncope compared with patients with other causes (P<0.001). The diagnostic accuracies for cardiac syncope, as quantified by the area under the curve, were 0.80 (95% confidence interval [CI], 0.76–0.84), 0.69 (95% CI, 0.64–0.74), 0.58 (95% CI, 0.52–0.63), and 0.68 (95% CI, 0.63–0.73), respectively. In conjunction with the ED probability (0.86; 95% CI, 0.82–0.90), MRproANP, but not the other prohormone, improved the area under the curve to 0.90 (95% CI, 0.87–0.93), which was significantly higher than for the ED probability alone (P=0.003). An algorithm to rule out cardiac syncope combining an MRproANP level of <77 pmol/L and an ED probability of <20% had a sensitivity and a negative predictive value of 99%.

Conclusions

The use of MRproANP significantly improves the early detection of cardiac syncope among unselected patients presenting to the ED with syncope.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01548352.

Impact of pharmacological spasm provocation test in patients with a history of syncope

Coronary artery spasm is involved in the pathogenesis of various cardiac disorders. We investigated patients with a history of syncope who underwent elective coronary angiography. We retrospectively analyzed 5781 consecutive patients who had diagnostic or follow-up angiography during a 26-year period. During this period, we found 95 patients with a history of syncope before elective coronary angiography. Pharmacological spasm provocation testing was performed in 64 patients with a history of syncope (<1 year). Positive pharmacological response was observed in 48 patients, while the remaining 16 patients had negative tests. Positive spasm was defined as a transient ≥90% narrowing with ischemic electrocardiographic changes. Among the 64 patients, definite coronary spastic angina (CSA) was found in 35 patients (54.7%) and suspected CSA was found in 13 patients (20.3%). Among the 35 patients with definite CSA, 22 patients (62.9%) had chest symptoms before syncope, but 13 (37.1%) had no chest symptom before syncope. No difference in clinical characteristics was observed between the two groups. Focal spasm during pharmacological spasm provocation tests was significantly higher in patients with chest symptoms than in those without chest symptoms before syncope (54.3 vs. 12.0%, p < 0.002). CSA was observed in 75.0% of patients with a history of syncope (<1 year). Thirteen patients with definite CSA had neither chest pain nor chest pressure before syncope. We should therefore investigate coronary artery spasm as a potential etiology in patients with a history of syncope.

A new test for diagnosing vasovagal syncope: Standing after treadmill test with sublingual nitrate administration

Introduction

Increased adrenergic tone might be an additional trigger of orthostatic stress of vasovagal syncope (VVS). Exercise before standing might provide increased sensitivity compared to standing using a sublingual nitroglycerines protocol during tilt table testing. The aim of this study was to evaluate the diagnostic value of treadmill testing before standing with nitroglycerin administration.

Methods and results

A total of 36 patients with syncope or presyncope were enrolled for the test. VVS was confirmed in 29 patients according to the Calgary Score (≥ -2), including 20 patients who were likely to have typical (classical) VVS. All 36 subjects were subjected to a novel provocation test consisting of treadmill test using the Bruce protocol followed by standing with administration of 300 μg sublingual nitroglycerin. Consequently, syncope or presyncope occurred in 22 patients of the 36 patients. The sensitivity and a specificity of the test for Calgary score based VVS was 82.7% and 85.75%, respectively. Reproducibility rate for typical VVS was 90% (18 of 20). In all symptomatic patients, systolic blood pressure dropped to < 90 mmHg and symptom occurred a mean of 6.7 ± 2.3 minutes after the nitroglycerine administration. No patient required anticholinergics injection to restore vital signs.

Conclusions

Treadmill test with administration of sublingual nitroglycerines might be safely used to reproduce syncope in patients with VVS. More clinical experience and confirmation are needed to validate this protocol.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Asystole in the epilepsy unit

BACKGROUND

Early identification of cardiac asystole as a reason for syncope is of uttermost significance, as insertion of a cardiac pacemaker can save the patient's life and prevent severe injury. The aim of this work was to emphasize the subtle and unusual presentations of asystole in patients evaluated in epilepsy units.

METHODS

We reviewed the clinical presentation, ECG and EEG data of a series of seven patients who were evaluated in four epilepsy units and were diagnosed with asystole.

RESULTS

Three patients had unusual clinical manifestations of cardiac asystole, resembling epileptic seizures. Three patients had asystole induced by epileptic seizures and in one patient the diagnosis was not clear. All patients except one were implanted with a pacemaker and improved clinically.

CONCLUSIONS

Seizure-induced asystole is a rare complication of epilepsy and asystole may clinically mimic epileptic seizures. A high level of suspicion and thorough prolonged cardiac and EEG monitoring are mandatory for reaching the right diagnosis. As the diagnosis is rare and difficult to reach, a flow chart to assist diagnosis is suggested.

Diagnostic utility of carotid artery duplex ultrasonography in the evaluation of syncope: a good test ordered for the wrong reason

AIMS

Syncope refers to a transient loss of consciousness and postural tone secondary to cerebral hypoperfusion. Guidelines recommend against neurovascular testing in cases of syncope without neurologic symptoms; however, many pursue carotid artery duplex ultrasonography (CUS) due to the prognostic implications of identified cerebrovascular disease. Our objective was to determine the diagnostic utility of CUS in the evaluation of syncope and the identification of new or severe atherosclerosis with the potential to change patient management.

METHODS AND RESULTS

We reviewed records of 569 patients with CUS ordered for the primary indication of syncope through an accredited vascular laboratory at an academic, urban medical centre. Findings on CUS, patient demographic, clinical and laboratory information, and medications within 6 months of the CUS exam were reviewed. Bivariate relationships between key medical history characteristics and atherosclerosis status (known vs. new disease) were examined. Among 495 patients with complete information, cerebrovascular findings could potentially explain syncope in 2% (10 patients). Optimization of cardiovascular risk factors would benefit patients with known (56.6%) and new atherosclerosis (33.5%) with suboptimal lipid control, (LDL > 70 in 42.2 and 34.9% respectively; LDL > 100 in 15.7 and 20.4%), and those not on high-intensity statin therapy (80 and 87.5%) or antiplatelet medications (13.2 and 50.6%).

CONCLUSION

CUS is a low-yield diagnostic test in the evaluation of syncope, but it is useful in the diagnosis of atherosclerosis and identification of subjects who would benefit from optimal medical therapy.