Vagal sensory neurons mediate the Bezold-Jarisch reflex and induce syncope.

Visceral sensory pathways mediate homeostatic reflexes, the dysfunction of which leads to many neurological disorders1. The Bezold-Jarisch reflex (BJR), first described2,3 in 1867, is a cardioinhibitory reflex that is speculated to be mediated by vagal sensory neurons (VSNs) that also triggers syncope. However, the molecular identity, anatomical organization, physiological characteristics and behavioural influence of cardiac VSNs remain mostly unknown. Here we leveraged single-cell RNA-sequencing data and HYBRiD tissue clearing4 to show that VSNs that express neuropeptide Y receptor Y2 (NPY2R) predominately connect the heart ventricular wall to the area postrema. Optogenetic activation of NPY2R VSNs elicits the classic triad of BJR responses-hypotension, bradycardia and suppressed respiration-and causes an animal to faint. Photostimulation during high-resolution echocardiography and laser Doppler flowmetry with behavioural observation revealed a range of phenotypes reflected in clinical syncope, including reduced cardiac output, cerebral hypoperfusion, pupil dilation and eye-roll. Large-scale Neuropixels brain recordings and machine-learning-based modelling showed that this manipulation causes the suppression of activity across a large distributed neuronal population that is not explained by changes in spontaneous behavioural movements. Additionally, bidirectional manipulation of the periventricular zone had a push-pull effect, with inhibition leading to longer syncope periods and activation inducing arousal. Finally, ablating NPY2R VSNs specifically abolished the BJR. Combined, these results demonstrate a genetically defined cardiac reflex that recapitulates characteristics of human syncope at physiological, behavioural and neural network levels.

Diagnosis of Brugada Syndrome With a Sodium-Channel-Blocker Test: Who Should Be Tested? Who Should Not?

Intravenous infusion of sodium-channel blockers (SCB) with either ajmaline, flecainide, procainamide, or pilsicainide to unmask the ECG of Brugada syndrome is the drug challenge most commonly used for diagnostic purposes when investigating cases possibly related to inherited arrhythmia syndromes. For a patient undergoing an SCB challenge, the impact of a positive result goes well beyond its diagnostic implications. It is, therefore, appropriate to question who should undergo a SCB test to diagnose or exclude Brugada syndrome and, perhaps more importantly, who should not. We present a critical review of the benefits and drawbacks of the SCB challenge when performed in cardiac arrest survivors, patients presenting with syncope, family members of probands with confirmed Brugada syndrome, and asymptomatic patients with suspicious ECG.

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.

High-risk admission prior to transcatheter aortic valve replacement and subsequent outcomes.

BACKGROUND: Severe, symptomatic aortic stenosis may cause heart failure, acute myocardial infarction, or syncope; limited data exist on the occurrence of such events before transcatheter aortic valve replacement (TAVR) and their impact on subsequent outcomes. Thus, we investigated the association between a preceding event and outcomes after TAVR. METHODS: From 2014 to 2021 all Danish patients who underwent TAVR were included. Preceding events up to 180 days before TAVR were identified. A preceding event was defined as a hospitalization for heart failure, acute myocardial infarction, or syncope. The 1-year risk of all-cause death, and cardiovascular or all-cause hospitalization was compared for patients with versus without a preceding event using Kaplan-Meier, Aalen-Johansen, and in Cox regression analyses adjusted for patient characteristics. RESULTS: Of 5,851 patients included, 759 (13.0%) had a preceding event. The median age was 81 years in both groups. Male sex and frailty were more prevalent in patients with a preceding event (males: 64.7% vs 55.2%, frailty: 49.6% vs 40.6%). The most common type of preceding event was a hospitalization for heart failure (n = 524). For patients with a preceding event, the 1-year risk of death was 11.7% (95% CI: 9.4%-14.1%) versus 8.0% (95% CI: 7.2%-8.7%) for patients without. The corresponding adjusted hazard ratio (aHR) was 1.29 (95%CI: 1.01-1.64). Mortality was highest for patients with a preceding event of a heart failure admission (1-year risk: 13.5% [95%CI: 10.5%-16.5%]). Comparing patients with a preceding event to those without, the 1-year risk for cardiovascular rehospitalization was 15.0% versus 8.2% (aHR 1.60 [95%CI: 1.29-1.99]) and 57.6% versus 50.6% for all-cause rehospitalization (aHR 1.08 [95%CI: 0.87-1.20]). CONCLUSIONS: A hospitalization for heart failure, myocardial infarction, or syncope prior to TAVR was associated with a poorer prognosis and could represent a group to focus resource management on. Interventions to prevent preceding events and improvements in pre- and post-TAVR optimization of these patients are warranted.

Cardioneuroablation for pediatric patients with functional sinus node dysfunction and paroxysmal atrioventricular block.

INTRODUCTION: Severe transitory episodes of bradycardia with subsequent syncope in children are common, and generally portend a benign prognosis. Rarely, patients may experience prolonged asystolic episodes secondary to significant sinus pauses (SP) or paroxysmal atrioventricular block (AVB). Cardioneuroablation (CNA) is a catheter-based intervention, used to identify and ablate the epicardial ganglionated plexi (GP), which results in disruption of the vagal-mediated parasympathetic input to the sinus and atrioventricular node. OBJECTIVE: Describe the methodology and role of CNA for treatment of pediatric patients with functional AVB or SP. METHODS: This is a single-center, case series study. Patients with SP or AVB, 21 years of age or younger, who underwent CNA between 2015 and 2021 were included. CNA was performed via anatomically guided and high-frequency stimulation methods. RESULTS: Six patients were included. The median age was 18.9 years (range 12.3-20.9 years), 33% female. Two patients had prolonged SP, two had paroxysmal AVB, and two had both SP and AVB. Four patients had prior syncope. The median longest pause was 8.9 s (range 3.9-16.8) with 11 total documented pauses (range 2-231) during the 6 months pre-CNA. Post-CNA, the median longest pause was 1.3 s (range 0.8-2.2) with one documented SP after termination of atrial tachycardia at the 3-month follow-up. At 6 months, the median longest pause was 1.1 s (0.8-1.3) with 0 documented pauses. No patients had syncope post-CNA. CONCLUSION: CNA may be an effective alternative to pacemaker implantation in pediatric patients with syncope or significant symptoms secondary to functional SP or AVB.

Mechanism-based therapy of non-cardiac syncope: a practical guide.

The term non-cardiac syncope includes all forms of syncope, in which primary intrinsic cardiac mechanism and non-syncopal transient loss of consciousness can be ruled out. Reflex syncope and orthostatic hypotension are the most frequent aetiologies of non-cardiac syncope. As no specific therapy is effective for all types of non-cardiac syncope, identifying the underlying haemodynamic mechanism is the essential prerequisite for an effective personalized therapy and prevention of syncope recurrences. Indeed, choice of appropriate therapy and its efficacy are largely determined by the syncope mechanism rather than its aetiology and clinical presentation. The two main haemodynamic phenomena leading to non-cardiac syncope include either profound hypotension or extrinsic asystole/pronounced bradycardia, corresponding to two different haemodynamic syncope phenotypes, the hypotensive and bradycardic phenotypes. The choice of therapy-aimed at counteracting hypotension or bradycardia-depends on the given phenotype. Discontinuation of blood pressure-lowering drugs, elastic garments, and blood pressure-elevating agents such as fludrocortisone and midodrine are the most effective therapies in patients with hypotensive phenotype. Cardiac pacing, cardioneuroablation, and drugs preventing bradycardia such as theophylline are the most effective therapies in patients with bradycardic phenotype of extrinsic cause.

Procedural and Intermediate-term Results of the Electroanatomical-guided Cardioneuroablation for the Treatment of Supra-Hisian Second- or Advanced-degree Atrioventricular Block: the PIRECNA multicentre registry.

AIMS: Prior case series showed promising results for cardioneuroablation in patients with vagally induced atrioventricular blocks (VAVBs). We aimed to examine the acute procedural characteristics and intermediate-term outcomes of electroanatomical-guided cardioneuroablation (EACNA) in patients with VAVB. METHODS AND RESULTS: This international multicentre retrospective registry included data collected from 20 centres. Patients presenting with symptomatic paroxysmal or persistent VAVB were included in the study. All patients underwent EACNA. Procedural success was defined by the acute reversal of atrioventricular blocks (AVBs) and complete abolition of atropine response. The primary outcome was occurrence of syncope and daytime second- or advanced-degree AVB on serial prolonged electrocardiogram monitoring during follow-up. A total of 130 patients underwent EACNA. Acute procedural success was achieved in 96.2% of the cases. During a median follow-up of 300 days (150, 496), the primary outcome occurred in 17/125 (14%) cases with acute procedural success (recurrence of AVB in 9 and new syncope in 8 cases). Operator experience and use of extracardiac vagal stimulation were similar for patients with and without primary outcomes. A history of atrial fibrillation, hypertension, and coronary artery disease was associated with a higher primary outcome occurrence. Only four patients with primary outcome required pacemaker placement during follow-up. CONCLUSION: This is the largest multicentre study demonstrating the feasibility of EACNA with encouraging intermediate-term outcomes in selected patients with VAVB. Studies investigating the effect on burden of daytime symptoms caused by the AVB are required to confirm these findings.

The triggers of situational syncope do not influence the head-up tilt test response and prognosis.

AIMS: The study evaluated the positivity rate, haemodynamic responses, and prognosis in terms of syncopal recurrence among patients with situational syncope (SS) stratified according to the underlying situational triggers. METHODS AND RESULTS: We retrospectively evaluated all consecutive patients with SS who underwent nitroglycerine (NTG)-potentiated head-up tilt test (HUTT) at Syncope Unit of the University of Campania 'Luigi Vanvitelli'-Monaldi Hospital from 1 March 2017 to 1 May 2023. All patients were followed for at least one year. The study population was divided according to the underlying triggers (micturition, swallow, defaecation, cough/sneeze, post-exercise). Two hundred thirty-six SS patients (mean age 50 ± 19.3 years; male 63.1%) were enrolled; among them, the situational trigger was micturition in 109 patients (46.2%); swallow in 32 (13.6%) patients; defaecation in 35 (14.8%) patients; post-exercise in 41 (17.4%) patients; and cough/sneeze in 17 (7.2%) patients. There were no significant differences in baseline clinical characteristics and HUTT responses between different situational triggers. The Kaplan-Meier analysis did not show a statistically different rate of syncope recurrence across patients stratified by baseline situational triggers (log-rank P = 0.21). CONCLUSION: Situational syncope appears to be a homogenous syndrome, and different triggers do not impact the HUTT response or syncope recurrence at 1 year.

Syncope While Driving and the Risk of a Subsequent Motor Vehicle Crash.

STUDY OBJECTIVE: Syncope that occurs while driving can result in a motor vehicle crash. Whether individuals with a prior syncope-related crash exhibit an exceptional risk of subsequent crash remains uncertain. METHODS: We performed a population-based retrospective observational study of patients diagnosed with 'syncope and collapse' at any of 6 emergency departments in British Columbia, Canada (2010 to 2015). Data were obtained from chart abstraction, administrative health records, insurance claims and police crash reports. We compared crash-free survival among individuals with crash-associated syncope (a crash and an emergency visit for syncope on the same date) to that among controls with syncope alone (no crash on date of emergency visit for syncope). RESULTS: In the year following their index emergency visit, 13 of 63 drivers with crash-associated syncope and 852 of 9,160 controls with syncope alone experienced a subsequent crash as a driver (crash risk 21% versus 9%). After accounting for censoring and potential confounders, crash-associated syncope was not associated with a significant increase in the risk of subsequent crash (adjusted hazard ratio [aHR] 1.38, 95% confidence interval [CI] 0.78 to 2.47). Individuals with crash-associated syncope were 31-fold more likely to have physician driving advice documented during their index visit (prevalence ratio 31.0, 95% CI, 21.3 to 45.1). In the subgroup without documented driving advice, crash-associated syncope was associated with a significant increase in subsequent crash risk (aHR 1.88, 95% CI 1.06 to 3.36). CONCLUSIONS: Crash risk after crash-associated syncope appears similar to crash risk after syncope alone.

Use of a leadless pacemaker in the management of swallow syncope: A case report.

A 41-year-old male presented with syncope whilst eating and was subsequently demonstrated to have recurrent symptomatic sinus pauses whilst swallowing. Following the exclusion of structural heart disease, he was diagnosed with swallow syncope, an uncommon variant of neurocardiogenic syncope. To avoid long-term complications of a transvenous pacemaker, the case was managed with a leadless pacemaker which resulted in complete resolution of symptoms.

Syncope in older adults: challenges, approach and treatment.

Syncope can have devastating consequences, resulting in injuries, accidents or even death. In our ageing society, the subsequent healthcare usage, such as emergency room presentations, surgeries and hospital admissions, forms a significant and growing socioeconomic burden. Causes of syncope in the older adult include orthostatic hypotension, carotid sinus syndrome, vasovagal syncope, structural cardiac abnormalities, cardiac arrhythmias and conduction abnormalities. As stated in the recently published World Falls Guidelines, syncope in older adults often presents as falls, which is either due to amnesia for loss of consciousness, or pre-syncope leading to a fall, especially in those prone to falls with several other risk-factors for falls present. This difference in presentation can hinder the recognition of syncope. In patients with unexplained falls, or in whom the history comprises red flags for potential syncope, special attention to (pre)syncope is therefore warranted. When syncope is mistaken for other causes of a transient loss of consciousness, such as epileptic seizures, or when syncope presents as falls, patients are often referred to multiple specialists, which may in turn lead to excessive and unnecessary diagnostic testing and costs. Specialist services that are able to provide a comprehensive assessment can improve diagnostic yield and minimise diagnostic testing, thus improving patient satisfaction. Comprehensive assessment also leads to reduced length of hospital stay. Increasingly, geriatricians are involved in the assessment of syncope in the older patient, especially given the overlap with falls. Therefore, awareness of causes of syncope, as well as state-of-the-art assessment and treatment, is of great importance.

Relationship between hemodynamic type and syncopal symptoms in pediatric vasovagal syncope.

Vasovagal syncope (VVS) is a clinically common neurally mediated syncope. The relationship between different hemodynamic types of VVS and clinical syncopal symptoms has not been reported. The purpose of this research is to explore relationship between hemodynamic types and syncopal symptoms in pediatric VVS. Two thousand five hundred thirteen patients diagnosed with VVS at the age of 3-18 years, average age was 11.76 ± 2.83 years, including 1124 males and 1389 females, due to unexplained syncope and pre-syncope from single-center of January 2001 to December 2021 were retrospectively analyzed. Subjects were divided into two groups according to the presence or absence of syncopal symptoms: syncope group (1262 cases) and pre-syncope group (1251 cases). (1) Baseline characteristics: age, height, weight, systolic blood pressure (SBP), and diastolic blood pressure (DBP) increased in the syncope group compared with the pre-syncope group; the composition ratio of females was more than that of males in the syncope group; and the composition ratio of VVS-cardioinhibited (VVS-CI) and VVS-mixed (VVS-M) was more in the syncope group than that of the pre-syncope group (all P < 0.05). (2) Univariate analysis: age, height, weight, SBP, DBP, female, VVS-CI, and VVS-M were potential risk factors for the presence of syncopal symptoms (all P < 0.05). (3) Multivariate analysis: VVS-CI and VVS-M were independent risk factors for the presence of syncopal symptoms, with an increased probability of 203% and 175%, respectively, compared to VVS-vasoinhibited (VVS-VI) (all P < 0.01). CONCLUSION: The hemodynamic type of pediatric VVS is closely related to the syncopal symptoms. WHAT IS KNOWN: • There are varying probabilities of syncopal episodes in different hemodynamic types of VVS, and there is a lack of research to assess the comparative risk of syncope in children with different hemodynamic types of VVS. WHAT IS NEW: • The probability in presence of syncopal symptoms varies greatly between different hemodynamic types of VVS. • VVS-CI and VVS-M had a 203% and 175% increased risk in presence of syncopal symptoms compared with VVS-VI, respectively.

Asystole on loop recorder in patients with unexplained syncope and negative tilt testing: age distribution and clinical predictors.

BACKGROUND: Approximately 50% of patients with unexplained syncope and negative head-up tilt test (HUTT) who have an electrocardiogram (ECG) documentation of spontaneous syncope during implantable loop recorder (ILR) show an asystolic pause at the time of the event. OBJECTIVE: The aim of the study was to evaluate the age distribution and clinical predictors of asystolic syncope detected by ILR in patients with unexplained syncope and negative HUTT. METHODS: This research employed a retrospective, single-center study of consecutive patients. The ILR-documented spontaneous syncope was classified according to the International Study on Syncope of Uncertain Etiology (ISSUE) classification. RESULTS: Among 113 patients (54.0 ± 19.6 years; 46% male), 49 had an ECG-documented recurrence of syncope during the observation period and 28 of these later (24.8%, corresponding to 57.1% of the patients with a diagnostic event) had a diagnosis of asystolic syncope at ILR: type 1A was present in 24 (85.7%), type 1B in 1 (3.6%), and type 1C in 3 (10.7%) patients. The age distribution of asystolic syncope was bimodal, with a peak at age < 19 years and a second peak at the age of 60-79 years. At Cox multivariable analysis, syncope without prodromes (OR 3.7; p = 0.0008) and use of beta blockers (OR 3.2; p = 0.002) were independently associated to ILR-detected asystole. CONCLUSIONS: In patients with unexplained syncope and negative HUTT, the age distribution of asystolic syncope detected by ILR is bimodal, suggesting a different mechanism responsible for asystole in both younger and older patients. The absence of prodromes and the use of beta blockers are independent predictors of ILR-detected asystole.

Fasciculoventricular accessory pathway masked extensive atrioventricular conduction system disease in a patient with PRKAG2 syndrome.

A 23-year-old male with a history of ventricular pre-excitation and atrial flutter presented for evaluation after recurrent syncope. The possible mechanism of syncope erroneously attributed to pre-excited atrial flutter with fast heart rates in the first hospitalization. The patient was found to have advanced heart block and PRKAG2 genetic mutation in the second hospitalization. The genetic findings and clinical features are consistent with PRKAG2 syndrome (PS). PS is a rare, autosomal dominant inherited disease, characterized by ventricular pre-excitation, supraventricular tachycardia, and cardiac hypertrophy. It is frequently followed by atrial-fibrillation-induced ventricular fibrillation and advanced heart blocks. An accurate differential diagnosis of syncope is important because of the different arrhythmic features and clinical course of PS.

Diagnosis and treatment of recurrent syncope in a middle-aged women.

A 50-year-old female patient, presented with repeated syncope for more than 2 years. Prior assessments were conducted at different hospitals, but no definite abnormalities were found. The patient's fear and anxiety about possible future attacks were escalating. Through a Head-up tilt test, the cause was finally identified as vasovagal syncope. Following a 5-min administration of nitroglycerin, the patient reported palpitations, nausea, and deep, rapid breathing. The electrocardiogram initially showed a first-degree atrioventricular block, progressing swiftly to a second-degree type I atrioventricular block-high atrioventricular block. Immediate intervention was undertaken, but blood pressure was not instantly ascertainable, coinciding with an abrupt loss of consciousness. Subsequent electrocardiographic findings included paroxysmal third-degree atrioventricular block, sinus arrest, and complete cardiac arrest, prompting the initiation of external cardiac compressions. The longest recorded ventricular arrest approximated 15 s, with sinus rhythm resuming post 10 s of cardiac compressions and the patient regaining consciousness. The patient underwent vagal ablation and no longer experienced syncope.

Patient Perception of Cough in Interstitial Lung Disease; Impact of Cough Hypersensitivity.

INTRODUCTION: Cough is common in interstitial lung disease (ILD) and is associated with disease progression, yet its mechanisms are understudied. We investigated cough hypersensitivity features and impact in ILD. METHODS: Participants with ILD and cough (n = 195) completed a multiple choice and free text questionnaire on cough sensations/triggers and impacts. RESULTS: The majority of participants were male (54%), aged > 65 (64%), with idiopathic pulmonary fibrosis (IPF, 75%). Common cough triggers were body position (74%), physical activity (72%), and talking (62%). Common laryngeal sensations were globus (43%), and itch/tickle (42%). Cough impacted everyday life in 55%, and all activities in 31%, causing exhaustion (59%), social embarrassment (70%), urinary incontinence (46% females), and syncope/pre-syncope (12%). The total number of cough-provoking sensations/triggers correlated with impacts; ρ = 0.73, p < 0.001. CONCLUSION: Cough hypersensitivity symptoms are prevalent in ILD and detrimentally affect quality of life. Further studies investigating mechanisms of cough hypersensitivity and targeted pharmacotherapy are warranted.

Waterpipe vs non-Waterpipe carbon monoxide poisoning: Comparison of patient characteristics, clinical presentation and outcomes.

OBJECTIVE: The aim of this study is to describe the difference between carboxyhemoglobin (CO-Hb) acute poisoning caused by waterpipe vs non-waterpipe exposures as they relate to demographics, clinical presentations and outcome of patients. DESIGN: Retrospective cohort study conducted in the Emergency Department (ED) at the Lebanon. PATIENTS: All adult patients presenting with a CO-Hb level ≥ 10 between January 2019 and August 2023 with exposure types stratified as waterpipe or non-waterpipe. MEASUREMENTS AND MAIN RESULTS: 111 ED visits were identified. Among these, 73.9% were attributed to waterpipe exposure, while 26.1% were non-waterpipe sources. These included cigarette smoking (17.2%), burning coal (24.1%), fire incidents (3.6%), gas leaks (6.9%), heating device use (10.3%), and undocumented sources (37.9%). Patients with waterpipe-related carbon monoxide exposure were younger (41 vs 50 years, p = 0.015) women (63.4 vs 41.4%, p = 0.039) with less comorbidities compared to non-waterpipe exposures (22.2 vs 41.4%, p = 0.047). Waterpipe smokers were more likely to present during the summer (42.7 vs 13.8%, p = 0.002) and have shorter ED length of stays (3.9 vs 4.5 h, p = 0.03). A higher percentage of waterpipe smokers presented with syncope (52.4 vs 17.2%, p = 0.001) whereas cough/dyspnea were more common in non-waterpipe exposures (31 vs 9.8%, p = 0.006). The initial CO-Hb level was found to be significantly higher in waterpipe exposure as compared to non-waterpipe (19.7 vs 13.7, p = 0.004). Non-waterpipe exposures were more likely to be admitted to the hospital (24.1 vs 4.9%, p = 0.015). Waterpipe smokers had significantly higher odds of experiencing syncope, with a 5.74-fold increase in risk compared to those exposed to non-waterpipe sources (p = 0.004) irrespective of their CO-Hb level. Furthermore, males had significantly lower odds of syncope as compared to females, following carbon monoxide exposure (aOR 0.31, 95% CI 0.13-0.74). CONCLUSION: CO-Hb poisoning related to waterpipe smoking has distinctive features. Syncope is a commonly associated presentation that should solicit a focused social history in communities where waterpipe smoking is common. Furthermore, CO-Hb poisoning should remain on the differential in patients presenting with headache, syncope, dizziness, vomiting or shortness of breath, even outside of the non-waterpipe exposure peaks of winter season.

What are those intermittent "S" waves?

A 69-year-old woman had three syncopal events while flying on an airplane. She was found to be profoundly bradycardic. Two 12­lead electrocardiograms (ECGs) showed ventricular rates in the thirties. In one, the QRS complexes were narrow. In the second ECG, there were wide negative deflections following the QRS complexes. Analysis of telemetry recordings revealed the underlying mechanism and helped establish appropriate programing of an implanted pacemaker.

Convulsive Syncope as a Complication of Outpatient Procedures: A Case Series and Review of the Literature.

ABSTRACT: Sports medicine providers often perform various outpatient procedures to manage musculoskeletal and neuropathic conditions. Vasovagal syncope is a rare but a possible complication. Convulsive syncope is one subtype that involves brief extensor stiffening and nonsustained myoclonus and can be easily mistaken for seizures. We present a case series of convulsive syncope as a complication of common sports medicine outpatient procedures. We aim to describe how to identify this condition, and offer risk stratification and management strategies to mitigate the risks of this complication. Sports medicine providers who routinely practice outpatient procedures should be aware of this complication. Simple changes in approaching the procedure may mitigate these risks. High- and intermediate-risk features of the syncopal episode should prompt physicians to seek further evaluation by a specialist to rule out more serious conditions. In all instances, appropriate on-site support and equipment for emergent resuscitation and management should be prepared.

Emergency Ultrasound Unveils Intermediate-High Risk Saddle Pulmonary Embolism with Extensive Bilateral Clot Burden, Masquerading as Micturition Syncope: A Case Report.

BACKGROUND: Isolated syncope as the manifestation of pulmonary embolism (PE) is a rare and diagnostically challenging presentation that often leads to delayed or missed diagnosis, increasing morbidity and mortality. In spite of emphasizing cardiovascular etiologies of syncope, current guidelines offer essentially no guidance in establishing a diagnostic workup for PE in these patients. By performing bedside echocardiography, emergency physicians can accurately identify concerning features suggestive of PE in patients with syncope. CASE REPORT: A 78-year-old man, receiving ertapenem via a peripherally inserted central catheter for treatment of extended spectrum ß-lactamase urinary tract infection, presented to the emergency department for isolated syncope with collapse while urinating. Arriving asymptomatic with normal vital signs and a benign physical examination, a presumptive diagnosis of micturition syncope was made. However, subtle vital sign changes on reassessment prompted performance of a point-of-care echocardiogram, which revealed signs of right heart strain. A computed tomography angiogram confirmed a saddle PE with extensive bilateral clot burden. Catheter-directed thrombectomy was performed via interventional radiology, with successful removal of pulmonary emboli. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Pulmonary embolism presenting as isolated syncope represents a daunting diagnostic dilemma, as emergency physicians may not consider it, or anchor on more benign etiologies of syncope. Although lacking sufficient sensitivity to rule out PE, point-of-care echocardiography to evaluate for signs of right heart strain can quickly and effectively point toward the diagnosis, while also assessing for other emergent cardiovascular causes of syncope. Given the lack of evidence-based guidance concerning PE presenting as syncope, bedside echocardiography should be highly considered as a part of the emergency physician's diagnostic workup, especially in patients with abnormal vital signs.