Evaluation and Management of Reflex Vasovagal Syncope—A Review

Syncope is a symptom that is commonly encountered in the practice and may point to a cardiac or neurological diagnosis. The evaluation of syncope rests on a thorough clinical evaluation, aided by electrocardiogram (ECG) findings, followed by risk stratification of the particular case. Once high-risk factors have been ruled out, the patient can be further diagnosed as having a reflex syncope (RS), orthostatic hypotension, or cardiac syncope based on specific clues. If the initial evaluation is not confirmatory various diagnostic tests may be used to guide further management (eg, long-term ECG monitoring, tilt table testing, etc). The management should be based on the overall profile of the patient and not only on any single test. In this review, we discuss the evaluation of a patient with RS and give an overview of treatments available for the patients.

Ictal Syncope or Isolated Syncope? A case report highlighting the overlap

Background Ictal bradyarrhythmia is a rare condition defined by temporal lobe epilepsy resulting in bradycardia or asystole and can result in syncope. This needs to be differentiated from isolated syncope in patients with seizure disorder, as treatment strategies differ. Case Summary A 50-year-old female with well-controlled temporal epilepsy and a 20-year seizure-free period presented to her neurologist with abrupt onset of sudden drop attacks, thought to be ictal events with potential underlying ictal bradyarrhythmia and was initially treated with escalation of anti-convulsant therapy. However, her workup was consistent with a diagnosis of cardiac syncope. She subsequently underwent successful insertion of a pacemaker, with no recurrence of her presenting episodes at a 13-month Follow-up. Discussion Ictal syncope and isolated syncope may share a common terminal pathway and may have similar presenting symptoms. In patients with known seizure disorder, loss of consciousness may be attributable to epileptic events, ictal syncope, or isolated syncope—which can be difficult to differentiate. This case highlights the ambiguous nature of such episodes and the importance of simultaneous EEG/ECG monitoring, as this can have implications on treatment.

To analyze the clinical characteristics of emergency syncope patients and explore their clinical treatment strategies

Objective To analyze the clinical characteristics of emergency syncope patients and explore the strategies in their clinical treatment. Methods Eighty-five patients with emergency syncope admitted to our hospital from January 2019 to April 2021 were reviewed. The clinical data of all patients were retrospectively analyzed. The common causes were analyzed and summarized, and the strategies in clinical treatment were proposed. Results The main causes of syncope are neuroreflex syncope, follow by cardiac syncope, cerebral syncope, orthostatic hypotension syncope, hysterical syncope and unexplained syncope. They accounted for 35.3%, 30.6%, 15.3%, 12.9%, 3.5%, and 2.4%, respectively. Conclusion Emergency department physicians should evaluate emergency syncope patients in time, identify patients as soon as possible, confirm the etiological diagnosis, and give reasonable and effective symptomatic treatment and treatment measures in order to improve the prognosis and ensure the life safety and quality of patients.

Cardiac syncope: lessons learned from Sir Roger Bannister's textbook

In the third article of the new Neurocardiology series, Helen Cowan looks at cardiac syncope and the link between the heart and brain.

Shenxian-Shengmai Oral Liquid Improves Sinoatrial Node Dysfunction through the PKC/NOX-2 Signaling Pathway

Sick sinus syndrome (SSS) is one of the common causes of cardiac syncope and sudden death; the occurrence of SSS is associated with the accumulation of ROS in the sinoatrial node (SAN). Shenxian-shengmai (SXSM) is a traditional Chinese medicine available as oral liquid that causes a significant increase in heart rate. The objective of this study is to observe the improvement of SXSM on SAN function in SSS mice and explore its potential mechanism. In the current study, SSS was simulated in mice by inducing SAN dysfunction using a micro-osmotic pump to inject angiotensin II (Ang II). The mouse model with SSS was used to determine the effect of SXSM on SAN function and to explore its potential mechanism. Furthermore, the HL-1 cell line, derived from mouse atrial myocytes, was used to simulate SAN pacemaker cells. Our results indicated that SXSM significantly increased the heart rate of SSS mice by reducing the AngII-induced accumulation of ROS in the SAN and by inhibiting the expression of HDAC4, thereby reducing the loss of HCN4, a critical component of the cardiac conduction system. MASSON staining revealed a reduction of SAN damage in SSS mice that were treated with SXSM compared with controls. In vitro experiments showed that AngII treatment caused an upregulation of the PKC/NOX-2 signaling pathway in HL-1 cells which could be prevented by pretreatment with SXSM. The protective effect of SXSM was attenuated upon treatment with the PCK agonist PMA. In conclusion, SXSM reduced the AngII-induced accumulation of ROS in the SAN through the PKC/NOX2 signaling pathway, improving the functioning of the SAN and preventing the decrease of heart rate in SSS mice.

Demographics of Syncope in a Regional Australia

Background Syncope is one of the commonest presentations to the Emergency Departments. There is limited data on the incidence of syncope in regional Australia. Syncope is classified by its aetiological causes and each cause is characterised by different clinical features and prognosis. Identifying the cause of syncope patients is essential to preventing patient morbidity and mortality. Investigating the demographics of syncope in regional Australia may lead to better outcome. Results The age-adjusted causes of syncope showed a significant rise in cardiac syncope in patients aged above 60 (P=0.03) whereas patients below 30 were more likely to suffer from reflex syncope (P=0.0001). There are considerable overlaps such as prodromal symptoms or prior positions of patients between different types of syncope. 77 from 178 Patients (43.3%) would be classified as high risk. 18 out of 24 (75%) cardiac syncope patients were classified as high-risk, whereas barely more than 35% (18 out of 51) of patients with reflex syncope were high-risk. Patients with cardiac syncope were more likely to be admitted or referred for further evaluation such as telemetry, Holter monitor and echocardiogram (P=0.0001). Cause-adjusted mortality showed that patients with orthostatic syncope had significantly worse outcome compared to other groups (P=0.04), cardiac syncope patients were not associated with increased mortality (P=0.37). Conclusions The current study showed that Syncope is a frequent diagnosis within the emergency department. The incidence of syncope of unknown cause remains very high despite extensive investigations. Clinical features such as prodromal symptoms, prior position or activities leading to syncope did not show significantly difference between causes, therefore are unreliable resources in determining the cause of syncope. Orthostatic syncope was associated with the highest mortality rate therefore we recommend paying particular attention, specialist referral and more extensive investigations in patients with orthostatic syncope.

New insights in diagnostics and therapies in syncope: a novel approach to non-cardiac syncope

This article aims to give advice on how to identify and manage patients with syncope who are at risk of severe outcomes, that is, at risk of trauma, potentially life-threatening episodes or frequent recurrences reducing quality of life. The first step of syncope diagnostic assessment is to identify patients with cardiac syncope, and once established, these patients must receive the adequate mechanism-specific treatment. If cardiac syncope is unlikely, reflex (neurally mediated) syncope and orthostatic hypotension are the most frequent causes of transient loss of consciousness. For these presentations, efficacy of therapy is largely determined by the mechanism of syncope rather than its aetiology or clinical features. The identified mechanism of syncope should be carefully assessed and assigned either to hypotensive or bradycardic phenotype, which will determine the choice of therapy (counteracting hypotension or counteracting bradycardia). The results of recent trials indicate that ‘mechanism-specific therapy’ is highly effective in preventing recurrences. Established mechanism-specific treatment strategies include withdrawal of hypotensive drugs, applying fludrocortisone and midodrine for the hypotensive phenotype and cardiac pacing in the bradycardic phenotype.

Clinical Management of Syncope in Emergency Department Based on Risk Stratification : A Review Literature

Background: Background Syncope is a frequent problem among patients who present to the ED, accounts for 3% of emergency department admission and 1% of hospitalization. It is characterized by a comparatively short and self-limited loss of consciousness, which is caused by temporary cerebral hypoperfusion. Objective: Therefore, Risk stratification performed in the ED can guide triage decisions, and Risk-stratifying patients into low, moderate, and high-risk groups can assist medical decisions and determine the patient’s disposition. Discussion: The central point of syncope progression pathophysiology is the reduction of systemic blood pressure (BP) with a drop in global cerebral blood flow. Based on the European Society of Cardiology (ESC) syncope practice guidelines, syncope is classified into three categories, Neurally-mediated syncope (neural reflex syncope), Orthostatic hypotension, Cardiac syncope. Proper evaluation of syncope cases could in turn enable timely hospitalization and treatment by syncope experts. Assessment of a patient with syncope can be difficult, requiring a wide variety of medical testing with high health care costs. Sometimes, even after a careful examina- tion, it may not be possible to determine a definitive etiology for syncope. Given these uncertainties, about one-third of emergency room (ER) syncope/collapse patients are referred for assessment to the hospital, including non to low-risk patients. establish the urgency of any further work-up. Conclusion: Syncope assessment and treatment are very difficult, and syncope cases should be treated and dispositioned properly using proper risk stratification guidelines.