Syncope after live attenuated influenza vaccine: Reports to the Vaccine Adverse Event Reporting System (2003-2024).

Vasovagal syncope, or fainting, can be triggered by various stimuli, including medical procedures. Syncope after vaccination has been reported, most commonly among adolescents, and can result in injuries. Using the Vaccine Adverse Event Reporting System (VAERS), we reviewed and summarized reports of syncope after live attenuated influenza vaccine, intranasal (LAIV) administered as the sole vaccine (i.e., no concomitant injections). From June 17, 2003 (date of LAIV licensure in the US) through May 31, 2024, VAERS received 50 reports of syncope after LAIV. Nearly half (23; 46 %) pertained to individuals 10-19 years of age. While the vast majority of reports (35; 70 %) did not describe any injuries, 15 people (30 %) were injured, most commonly by falling and hitting their head or face. Twenty-two people (44 %) required evaluation in the emergency department or doctor's office, including an individual who lost consciousness while he was driving home from the vaccination appointment. He did not report any injuries, but the car was severely damaged. Nearly three-quarters of people (37; 74 %) developed syncope within 15 min after vaccination, but fewer than half of reports (24; 48 %) stated that the patient had waited in the observation area for at 15 min. Based on approximately 111.9 million doses of LAIV distributed in the US during the same time period, the reporting rate is approximately 0.4 per million doses, suggesting that syncope following LAIV is rare. The information summarized here may enable clinicians, patients, and caregivers to make a more informed decision regarding preventing injuries that may occur following LAIV-related syncope.

Enhancing risk assessment in Chagas cardiomyopathy: Electrophysiology study stratified by Rassi score.

BACKGROUND: Chagas cardiomyopathy (CCM) is increasingly prevalent in developed countries due to migration from endemic areas. Accurate risk stratification is crucial due to the variable clinical course of CCM. OBJECTIVE: To analyze the association between Rassi score progression and electrophysiology study (EPS) changes in CCM patients. METHODS: This prospective, observational cohort study involved CCM patients from two tertiary hospitals. Patients were classified as low, intermediate, or high risk based on the Rassi score. Data collected included demographics, clinical history, and diagnostic tests. EPS assessed AH, HH, and HV intervals, and inducibility of ventricular arrhythmias. Follow-ups were at 30 days and six-month intervals, with individualized discussions for cardiac implantable electric devices (CIED) based on EPS results. RESULTS: Of 67 screened CCM patients, 59 underwent EPS. The mean Rassi score was 8.7 ±â€¯4.5 points, with 33.8 % low, 38.9 % intermediate, and 27.1 % high risk. EPS abnormalities were found in 57.6 % of patients, mainly VT/VF (52.5 %). Most induced ventricular arrhythmias were monomorphic VT (80.7 %). A significant association was found between Rassi score risk classification and EPS changes (OR = 1.88 95 %CI: 1.15-3.06 p = 0.02). Higher Rassi scores correlated with VT presence on EPS (p = 0.0036). Syncope/pre-syncope had an OR 2.45 95 %CI:1.21-4.94; p = 0.012, independent of Rassi risk. Decreased ejection fraction was linked to EPS changes (p = 0.04). CONCLUSION: EPS changes among CCM was associated with progression of the Rassi score, indicating its utility as a stratification tool. Factors such as the presence of syncope/pre-syncope, decreased LVEF and wall motion abnormalities emerged as independent predictors within Rassi scores for changes in EPS.

The incidence of atrial fibrillation detected by implantable loop recorders: a comparison between patients with and without embolic stroke of undetermined source.

Aims: Stroke is the most debilitating outcome of atrial fibrillation (AF). The use of implantable loop recorders increases the detection of AF episodes among patients with embolic stroke of undetermined source. The significance of device-detected AF, or subclinical AF, is unknown. This study aimed to compare the incidence of AF detected by implantable loop recorder in patients with and without embolic stroke of undetermined source. Methods and results: We retrospectively studied all patients without known AF who were referred to our institution for implantable loop recorder implantation following embolic stroke of undetermined source, syncope, or palpitations from March 2009 to November 2019. The primary endpoint was any detection of AF or atrial flutter by implantable loop recorder. Seven hundred and fifty patients were included and followed up for a mean duration of 731 days (SD 443). An implantable loop recorder was implanted following embolic stroke of undetermined source in 323 and for assessment of syncope, palpitations, or another reason in 427 patients. The incidence of AF was significantly (P < 0.001) higher among patients with embolic stroke of undetermined source compared with the non-embolic stroke of undetermined source group; 48.6% vs. 13.8% (for any duration of AF) and 32.2% vs. 12.4% (for AF lasting ≥30 s) both P < 0.001. Kaplan-Meier analysis showed significantly higher incidence of AF for incremental durations of AF up to >5.5 h, but not >24 h. This was driven by longest AF durations of <6 min and between 5.5 h and 24 h, suggesting a bimodal distribution. In a multivariable Cox regression analysis, embolic stroke of undetermined source independently conferred an almost 5-fold increase in the hazard for any duration of AF. Conclusion: The incidence of AF is significantly higher amongst embolic stroke of undetermined source vs. non-embolic stroke of undetermined source patients monitored constantly by an implantable loop recorder. A high number of embolic stroke of undetermined source survivors have short-duration AF episodes. Further work is needed to determine the optimal treatment strategy of these AF episodes in embolic stroke of undetermined source.

Autonomic dysfunction as a possible cause of sudden cardiac death in swimming sports.

Introduction: Human diving reflex is a well-studied phenomenon. However, very little is known about the possible relationship between augmented diving reflex and autonomic dysfunction. Methods: We retrospectively studied a group of four swimmers who underwent a diving reflex test as part of the examination due to symptoms related to autonomic dysfunction during swimming. The control group comprised 11 healthy swimmers with no history of these symptoms. A standardized diving reflex test was performed for each athlete in both groups. Hemodynamic profiles, including heart rate, stroke volume, and cardiac output, were recorded. Results: There were no statistically significant differences between the groups in any of the three parameters measured before the test. However, at the end of the test, each parameter (heart rate, stroke volume, and cardiac output) was significantly lower in the swimmers who presented with clinical symptoms related to autonomic dysfunction than in the control group. Conclusion: This observation could shed light on autonomic dysfunction as a possible cause of sudden cardiac death in swimming athletes. It also demonstrated that autonomic dysfunction is presented not only by decreased heart rate but also by stroke volume, causing a drop in cardiac output to the level of hemodynamic collapse.

Establishment and validation of a nomogram for predicting the risk of syncope after craniomaxillofacial surgery.

PURPOSE: To explore the influencing factors of syncope in patients after plastic surgery, establish a syncope risk prediction model, and verify its accuracy. METHODS: A total of 265 patients undergoing craniomaxillofacial surgery were included and divided into a syncope group and non-syncope group. Multivariate logistic regression analysis was used to screen for risk factors of syncope, and R language was used to establish a risk prediction nomogram of syncope in craniomaxillofacial surgery patients. The Hosmer-Lemeshow goodness-of-fit test was used to evaluate the fit of the model, and the receiver operating characteristic (ROC) curve was used to analyze the predictive value of the model. RESULTS: Syncope occurred in 87 of 265 patients (32.8%), and no syncope occurred in 178 patients (67.8%). Multivariate logistic regression analysis revealed statistical differences in age, orthostatic heart rate, orthostatic diastolic blood pressure, syncope history, weight loss history, and medication history between the 2 groups (P < 0.05). A nomogram was constructed for predicting the risk of syncope after craniomaxillofacial surgery, and the Hosmer-Lemeshow goodness-of-fit test proved that the nomogram fitted well (P = 0.431). The results of ROC curve analysis showed that the alignment graph model had high prediction accuracy; the area under the curve was 0.886 (95% confidence interval, 0.8381-0.9332). CONCLUSION: Evaluating the risk of syncope after craniomaxillofacial surgery is helpful and provides guidance for the formulation of preventive strategies.

Benefits and limitations of implantable loop recorders in the very elderly.

BACKGROUND: Implantable loop recorder (ILR) allows rhythm-monitoring up to 3 years. They are recommended in patients with recurrent syncope and for the detection of atrial fibrillation (AF) in patients with cryptogenic thromboembolic events. AF and syncope occur more often in elderly patients. However, data in this cohort is limited. METHODS AND RESULTS: All patients ≥ 80 years undergoing ILR-implantation between 2011 and 2022 in our center were included. Permanent pacemaker implantation (PPI) and oral anticoagulation due AF were defined as primary endpoints. Forty-five patients ≥ 80 years were included, 33 because of recurrent syncope and 12 because of suspected AF. The average follow up (FU) was 17.6 months. Overall in 22 patients, ILR-implantation led to a therapeutic consequence (48.9%). In the 12 patients who underwent ILR-implantation for detection of AF, AF was detected in nine patients (75%). In the 33 elderly patients who received ILR-implantation after syncope, 11 underwent PPI during FU (33.3%). One patient accidentally removed the ILR himself via the implantation-wound, and no other ILR-related complications were observed. CONCLUSION: ILR are effective and safe in elderly patients. AF was often found in patients with suspected AF, especially in patients after catheter ablation of only documented atrial flutter (AFlu). PPI-rate was high in patients with recurrent syncope and ILR-implantation. Further investigations are necessary to determine whether PPI may be considered in elderly patients with syncope even in the absence of a bifascicular block.

Clinical course in older patients diagnosed with syncope treated in Spanish emergency departments: results from the Emergency Department and Elder Needs-17 study. / Evolución clínica de los pacientes mayores diagnosticados de síncope en servicios de urgencias en España: resultados del estudio EDEN-17.

OBJECTIVE: To study factors associated with hospitalization in an unselected population of patients aged 65 years or older treated for syncope in Spanish hospital emergency departments (EDs). To determine the prevalence of adverse events at 30 days in patients discharged home and the factors associated with such events. METHODS: We included all patients aged 65 years or older who were diagnosed with syncope during a single week in 52 Spanish EDs, recording patient clinical and ED case management data. We compared the findings between hospitalized patients and those discharged home, following the latter for 30 days. In discharged patients, we explored predictors of a composite adverse-event outcome (occurrence of any of the following: ED revisits, hospitalization related to the index visit, or any-cause death). RESULTS: A total of 477 patients with syncope were identified; 67 (14%) were admitted, and 5 (7.5%) died. The median (interquartile range) length of hospital stay was 6 days (3-11 days). Comorbidity increased the probability of hospitalization (odds ratio, 2.172; 95% CI, 1.013-4.655). Among the 410 patients (86%) discharged home from the ED, 9.2% experienced an adverse event within 30 days (ED revisits, 8.,1%; hospitalization, 2.2%; death, 1.5%). No factors were associated with the 30-day composite outcome. CONCLUSIONS: The majority of patients aged 65 years or older are discharged home from EDs, and 30-day adverse events, while infrequent, are difficult to predict. Hospitalization was related to comorbidity and an absence of cognitive decline.

OBJETIVO: Investigar en una muestra no seleccionada de población mayor (65 o más años) atendida en servicios de urgencias hospitalarios (SUH) españoles por síncope los factores que se asociaron con la hospitalización, prevalencia de eventos adversos (EA) a 30 días y los factores asociados a estos entre los pacientes dados de alta desde urgencias. METODO: Se incluyeron todos pacientes con 65 o más años diagnosticados de síncope durante una semana en 52 SUH españoles. Se recogieron datos de la situación clínica y el manejo en urgencias, que se compararon entre los pacientes hospitalizados y los dados de alta directamente desde urgencias. Estos últimos fueron seguidos durante 30 días y se identificaron aquellos que presentaron un EA combinado (reconsulta en urgencias u hospitalización relacionada con el evento índice y muerte por cualquier causa), y se investigaron los factores que predecían dicho EA combinado. RESULTADOS: Se identificaron 477 pacientes con síncope. Hospitalizaron 67 (14%), de los que fallecieron 5 (7,5%) y la estancia mediana fue de 6 días (RIC 3-11). La comorbilidad incrementó la probabilidad de ingreso (OR: 2,172, IC 95%: 1,013-4,655). Entre los 410 pacientes dados de alta de urgencias (86%), el 9,2% tuvo un EA durante los 30 días siguientes (reconsulta a urgencias: 8,1%; hospitalización: 2,2%; muerte: 1,5%). Ningún factor se asoció con el riesgo de EA combinado a 30 días. CONCLUSIONES: La mayoría de los pacientes con 65 años o más atendidos en los SUH por síncope son dados de alta directamente desde urgencias, y los EA a los 30 días fueron poco frecuentes, pero difíciles de predecir. La hospitalización se relacionó con presencia de comorbilidad y ausencia de deterioro cognitivo.

Evaluation of consequential risk in ED patients with non-cardiac syncope.

BACKGROUND: Following standard syncope care, after exclusion of cardiac syncope, further workup is generally only recommended in cases of severe syncope due to consequential risk such that syncope is associated with injury or negative impacts on quality of life. This study is aimed to identify incidence and risk factors of severe syncope due to consequential risk, in a cohort of ED patients with non-cardiac syncope. METHODS: In a sample of 356 cases, we we conducted a case-control study comparing personal data, drug regimen, comorbidities, characteristics of syncope and previous episodes in patients with vs. without a severe syncope. RESULTS: Patients with severe syncope (120, 31.7% of total) resulted more frequently treated with a polypharmacy and CNS agents and affected by comorbidities entailing risk of falling; they more frequently had syncope occurred in a risky context, unwitnessed (55.8%), not preceded by prodromes (56.6%) and with clinical characteristics different from reflex syncope (82.3%); in these patients, previous episodes more frequently were clustered in the last years and complicated by major injuries. Absence of witnesses and prodromes and ED diagnosis different from reflex syncope resulted to be independently associated with severe syncope due to consequential risk. CONCLUSIONS: Syncope has a negative impact on a patient's life, through injuries or other personal consequences, in roughly one third of cases; to identity these patients, needing further investigation, emergency physicians should focus on episodes not preceded by prodromes, unwitnessed and with characteristic other than reflex syncope. Nonetheless, specific tools are needed to evaluate the impact of syncope on quality of life, to avoid clogging the path after ED discharge.

Cardioneuroablation: the known and the unknown.

Cardioneuroablation (CNA) is a novel interventional procedure for the treatment of recurrent vasovagal syncope (VVS) and advanced atrioventricular block secondary to hyperactivation of vagal tone in young patients. By damaging the cardiac parasympathetic ganglia, CNA seems to be able to mitigate and/or abolish the excessive vagal activity and improve patients' outcome. This review is intended to give a detailed and comprehensive overview of the current evidences regarding (1) the clinical applications of CNA (2) the identification of ablation targets and procedural endpoints (3) the medium-long term effect of the procedure and its future perspectives. However, clinical data are still limited, and expert consensus or recommendations in the guidelines regarding this technique are still lacking.

Cor Triatriatum Dexter with Noncompaction of Right Ventricle and Complete Heart Block: An Unholy Trinity.

Cor triatriatum (CT) or a triatrial heart is a rare congenital anomaly in which one of the atrial chambers is divided by a fibromuscular membrane. Of the two variants, CT dexter (right-sided CT) is still further rare than CT sinister (left-sided CT). Although CT sinister presents with features of left heart obstructive disease mimicking mitral stenosis, CT dexter is usually asymptomatic and is found incidentally on imaging. Here, we present a patient with an unusual case of complete heart block who was found to have CT dexter along with right ventricular noncompaction on imaging.

Pulmonary Embolism With Syncope Treated With Inari FlowTriever®.

Pulmonary embolism (PE) is a devastating disease that can range in severity from asymptomatic to fatal. The severity and the intervention required depend on the degree of hemodynamic instability and evidence of right heart strain demonstrated on diagnostic testing. Interventions include solely anticoagulation, systemic thrombolysis, catheter-directed therapies, or surgical embolectomy depending on the severity, patient's clinical picture, and clinician choice. Currently, there is a lack of evidence regarding which treatment is most suitable for submassive PE. This report demonstrates the benefits of aspiration thrombectomy, a catheter-directed therapy, utilizing the 24Fr Triever Aspiration Catheter (FlowTriever® system;Inari Medical, Irvine, California, United States) in a 57-year-old male patient with submassive PE. The FlowTriever retrieval/aspiration system is a single-use mechanical thrombectomy device indicated for use in the peripheral vasculature and pulmonary arteries. The patient presented with syncope and concern for head trauma ultimately requiring suction embolectomy utilizing the Inari FlowTriever system. We conclude that submassive PE can be effectively treated with aspiration thrombectomy in addition to long-term anticoagulation with excellent clinical outcomes.

[Catecholaminergic polymorphic ventricular tachycardia (CPVT): an insidious disease that can often lead to sudden cardiac death in young people]. / Die katecholaminerge polymorphe ventrikuläre Tachykardie (CPVT) : Eine tückische Erkrankung, die bei jungen Menschen zum plötzlichen Herztod führen kann.

The first symptoms of catecholaminergic polymorphic ventricular tachycardia (CPVT) usually occur in childhood and adolescence. 60% of patients experience syncope before the age of 40. Sudden cardiac death (SCD) is the first symptom of the disease in 30-50% of patients with CPVT. Early diagnosis is therefore crucial for the patient's prognosis. The diagnosis of CPVT is confirmed by a normal resting ECG, exclusion of structural heart disease, detection of bidirectional or polymorphic ventricular tachycardia (VT) in the stress ECG and/or detection of a pathogenic mutant in a gene associated with CPVT. Up to 60% of CPVT patients carry changes in the RYR2 gene. This gene encodes the cardiac ryanodine receptor, the most important Ca2+-releasing channel of the sarcoplasmic reticulum, which plays a central role in the contraction and relaxation of the heart muscle. If the function of the ryanodine receptor is impaired, too much calcium enters the cells, which triggers life-threatening arrhythmias. The overactive ryanodine receptor is therefore the main target for gene therapy methods. Even though the development of gene therapy is progressing, there is still no causal therapy available and it is all the more important to make a diagnosis as early as possible, which enables appropriate behavior and adequate symptomatic therapy. The decisive factor here is the evaluation of the genetic analysis in the context of the clinical findings. Based on this, recommendations can be made for preventive measures and the avoidance of specific triggers that could lead to life-threatening arrhythmias.

Prevalence and clinical predictors of vasodepressor syncope during head up tilt test.

INTRODUCTION: The aim of our study was to evaluate the prevalence and clinical predictors of vasodepressor (VD) response during head-up tilt test (HUTT) in patients with history of syncope admitted to a tertiary referral syncope unit. MATERIAL AND METHODS: We retrospectively evaluated all consecutive patients who underwent HUTT for suspected or established reflex syncope at our institution from March 1st, 2017, to June 1st, 2023. VD response was defined when syncope occurred during hypotension along with no or slight (< 10% bpm) decrease of heart rate. Univariate and multivariate analyses were performed to test the association of VD response to HUTT with a set of clinical covariates. RESULTS: 1780 patients (40 ± 19.9 years; 49.3% male) were included; among them, 1132 (63 %) showed a positive response to HUTT and 124 (7.0%) had a VD response. The prevalence of VD response showed a peak after 69 years (11.52% vs 6.18%; P = 0.0016), mainly driven by male patients (13.7% vs 4.9%; P < 0.0001). At multivariate analysis, age (OR: 1.15; P = 0.0026) was independently associated to HUTT-induced VD syncope; in contrast, smoking (OR: 0.33: P = 0.0009) and non-classical presentation of syncope (OR: 0.55; P = 0.0029) inversely correlated with VD syncope. CONCLUSIONS: VD response represents the less frequent responses among those induced by HUTT, accounting up to 7% of overall responses. A gender and age-related distribution has been shown. Advanced age was the only independent predictor of VD syncope; conversely, smoking and non-classical presentation of syncope reduced the probability of VD response to HUTT.

Guidelines for the diagnosis and treatment of neurally mediated syncope in children and adolescents (revised 2024).

BACKGROUND: Significant progress has been made in the diagnosis and treatment of pediatric syncope since the publication of the "2018 Chinese Pediatric Cardiology Society (CPCS) guideline for diagnosis and treatment of syncope in children and adolescents" ("2018 Edition Guidelines"). Therefore, we have revised and updated it to assist pediatricians in effectively managing children with syncope. DATA SOURCES: According to the "2018 Edition Guidelines", the expert groups collected clinical evidence, evaluated preliminary recommendations, and then organized open-ended discussions to form the recommendations. This guideline was developed by reviewing the literature and studies in databases including PubMed, Cochrane, EMBASE, China Biomedical Database, and Chinese Journal Full-text Database up to April 2024. Search terms included "syncope", "children", "adolescents", "diagnosis", and "treatment." RESULTS: The guidelines were based on the latest global research progress and were evidence-based. The classification of syncope etiology, diagnostic procedures, postural tests, such as the active standing test, head-up tilt test, and active sitting test, clinical diagnosis, and individualized treatment for neurally mediated syncope in pediatric population were included. CONCLUSIONS: The guidelines were updated based on the latest literature. The concepts of sitting tachycardia syndrome and sitting hypertension were introduced and the comorbidities of neurally mediated syncope were emphasized. Some biomarkers used for individualized treatment were underlined. Specific suggestions were put forward for non-pharmacological therapies as well as the follow-up process. The new guidelines will provide comprehensive guidance and reference for the diagnosis and treatment of neurally mediated syncope in children and adolescents.

Interhospital variability in hospital admissions for patients with low-risk syncope presenting to the emergency department.

Background: Guidelines and risk scores have sought to standardize the management of syncope in the emergency department (ED), but variation in practice remains. Objective: The purpose of this study was to explore factors associated with admission for patients presenting to the ED with low-risk syncope. Methods: Our study population included adult patients in the Nationwide Emergency Department Sample between 2006 and 2019 who presented to an ED with a primary diagnosis of syncope. Multivariable hierarchical logistic regression analyses determined the association of patient or hospital factors with admission. Reference effect measures methodology assessed the relative contributions of patient, hospital, and unmeasured hospital factors. Results: Of the 3,206,739 qualifying encounters during the study period, 804,398 (25.1%) met low-risk criteria. Of these patients, 20,260 were admitted to the hospital (2.5%). Factors associated with increased odds of admission included increasing age and weekend presentation to the hospital, while female sex, lack of medical insurance, hospital region, teaching status, and higher ED volume decile were associated with lower odds of admission. Reference effect measures methodology demonstrated that unmeasured site variability contributed the widest range of odds for admission (odds ratio [OR] 5th percentile vs 95th percentile 0.23-4.38) compared with the composite patient (OR 0.33-3.68) or hospital (OR 0.65-1.30) factors. Conclusion: Admission patterns for low-risk syncope varies widely across institutions. Unmeasured site variation contributes significantly to the variability in admission rates, suggesting which hospital a patient presents to plays a disproportionate role in admission decisions. Further guidance to reduce practice variation in syncope care in the ED is needed.

Syncope in the Emergency Department: A Case Report of a Rare Presentation of Favism.

Consumption of fava beans in a patient with glucose-6-phosphate dehydrogenase (G6PD) deficiency, also called favism, can lead to a haemolytic crisis. We report the case of a 69-year-old patient of Iranian origin admitted to the emergency department following syncope. The patient's comprehensive interview and blood analysis revealed that the patient presented a haemolytic crisis triggered by fava beans consumption, due to previously undiagnosed G6PD deficiency. The pathophysiology of favism is complex and clinical presentations of G6PD deficiency are numerous due to multiple genetic variants. Indirect signs, such as the presence of methemoglobinaemia and hemighosts on the blood smear, can aid in the diagnosis. This case highlights the importance of considering G6PD deficiency as a potential diagnosis in case of haemolytic crisis, even in elderly patients.

Pathophysiology of Syncope:Current Concepts and Their Development.

Syncope is a symptom in which transient loss of consciousness occurs as a consequence of a self-limited, spontaneously-terminating, period of cerebral hypoperfusion. Many circulatory disturbances (e.g. brady- or tachyarrhythmias, reflex cardioinhibition-vasodepression-hypotension) may trigger a syncope or near-syncope episode, and identifying the cause(s) is often challenging. Some syncope may involve multiple etiologies operating in concert, whereas in other cases multiple syncope events may be due to various differing causes at different times. In this communication we address current understanding of the principal contributors to syncope pathophysiology including examination of the manner in which concepts evolved, and an overview of factors that constitute consciousness and loss of consciousness, and aspects of neural-vascular control and communication that are impacted by cerebral hypo perfusion leading to syncope . Emphasis focuses on: 1) current understanding of the way transient systemic hypotension impacts brain blood flow and brain function, 2) the complexity and temporal sequence of vascular, humoral and cardiac factors that may accompany the most common causes of syncope, 3) the range of circumstances and disease states that may lead to syncope, and 4) clinical features associated with syncope and in particular the reflex syncope syndromes.