Observations on recurrent syncope and presyncope in 641 patients

Plasma human growth cytokines in children with vasovagal syncope

Purpose

The study was designed to investigate the profile of plasma human growth cytokines in pediatric vasovagal syncope (VVS).

Materials and methods

In the discovery set of the study, plasma human growth cytokines were measured using a Quantiboby Human Growth Factor Array in 24 VVS children and 12 healthy controls. Scatter and principal component analysis (PCA) diagrams were used to describe the samples, an unsupervised hierarchical clustering analysis was used to categorize the samples. Subsequently, the cytokines obtained from the screening assays were verified with a suspension cytokine array in the validation set of the study including 53 VVS children and 24 controls. Finally, the factors associated with pediatric VVS and the predictive value for the diagnosis of VVS were determined.

Results

In the discovery study, the differential protein screening revealed that the plasma hepatocyte growth factor (HGF), transforming growth factor b1 (TGF-b1), insulin-like growth factor binding protein (IGFBP)-4, and IGFBP-1 in children suffering from VVS were higher than those of the controls (all adjust P- value < 0.05). However, the plasma IGFBP-6, epidermal growth factor (EGF), and IGFBP-3 in pediatric VVS were lower than those of the controls (all adjust P- value < 0.01). Meanwhile, the changes of 7 differential proteins were analyzed by volcano plot. Unsupervised hierarchical cluster analysis demonstrated that patients in the VVS group could be successfully distinguished from controls based on the plasma level of seven differential proteins. Further validation experiments showed that VVS patients had significantly higher plasma concentrations of HGF, IGFBP-1, and IGFBP-6, but lower plasma concentrations of EGF and IGFBP-3 than controls. The logistics regression model showed that increased plasma concentration of HGF and IGFBP-1 and decreased plasma concentration of EGF were correlated with the development of pediatric VVS. ROC curve analysis showed that the abovementioned 3 proteins were useful for assisting the diagnosis of VVS.

Conclusion

Plasma human growth cytokine profiling changed in pediatric VVS. Elevated plasma concentrations of HGF and IGFBP-1, and decreased EGF were associated factors in the development of pediatric VVS. The abovementioned three proteins are helpful for the diagnosis of pediatric VVS.

A Complete Workup of Recurrent Syncope Caused by Significant Left Main Coronary Artery Stenosis

Syncope is usually caused by cerebral hypoperfusion. Differentials to consider during the workup of syncope includes vasovagal, orthostatic, drug-induced, arrhythmia, structural heart disease, and ischemic cardiomyopathy. 

An 81-year-old African American man with recurrent witnessed syncopal events and newly diagnosed heart failure underwent extensive cardiac workup including electrocardiograms (EKG), echocardiogram, Holter monitor, electrophysiology (EP) study, and coronary angiogram. The workup revealed ischemic ventricular tachycardia in the setting of significant coronary artery disease including 80% distal left main disease. The patient underwent a coronary artery bypass graft (CABG) with subsequent resolution of further syncopal events. The patient was successfully discharged with guideline-directed medical therapy for heart failure with reduced ejection fraction (HFrEF) and coronary artery disease (CAD). 

It is very rare for ischemic cardiomyopathy to present as syncope; however, it is not unheard of. Extensive transmural ischemia could lead to ventricular arrhythmias, a known cause of syncope. This rare presentation serves as a reminder to consider ischemic heart disease in the evaluation of syncope.

Cardiovascular autonomic nervous system responses and orthostatic intolerance in astronauts and their relevance in daily medicine

Background

The harsh environmental conditions during space travel, particularly weightlessness, impose a major burden on the human body including the cardiovascular system. Given its importance in adjusting the cardiovascular system to environmental challenges, the autonomic nervous system has been in the focus of scientists and clinicians involved in human space flight. This review provides an overview on human autonomic research under real and simulated space conditions with a focus on orthostatic intolerance.

Methods

The authors conducted a targeted literature search using Pubmed.

Results

Overall, 120 articles were identified and included in the review.

Conclusions

Postflight orthostatic intolerance is commonly observed in astronauts and could pose major risks when landing on another celestial body. The phenomenon likely results from changes in volume status and adaptation of the autonomic nervous system to weightlessness. Over the years, various non-pharmacological and pharmacological countermeasures have been investigated. In addition to enabling safe human space flight, this research may have implications for patients with disorders affecting cardiovascular autonomic control on Earth.

Genetic markers of vasovagal syncope

Vasovagal syncope may have a genetic predisposition. It has a high prevalence in some families, and children of a fainting parent are more likely to faint than those without a parent who faints. Having two fainting parents or a fainting twin increases the likelihood even further. Several genotypes appear to associate with the phenotype of positive tilt tests, but the control subjects are usually those who faint and have negative tilt tests. Twin studies, highly focused genome-wide association studies, and copy number variation studies all suggest there are loci in the genome that associate with vasovagal syncope, although the specific genes, pathways, and proteins are unknown. A recent multigenerational kindred candidate gene study identified 3 genes that associate with vasovagal syncope. The best evidence to date is for central signaling genes involving serotonin and dopamine. Genome-wide association studies to date have not yet been helpful. Our understanding of the genetic correlates of vasovagal syncope leaves ample opportunity for future work.

Low-blood pressure phenotype underpins the tendency to reflex syncope

BACKGROUND

We hypothesized that cardiovascular physiology differs in reflex syncope patients compared with the general population, predisposing such individuals to vasovagal reflex.

METHODS

In this multicohort cross-sectional study, we compared aggregate data of resting SBP, DBP, pulse pressure (PP) and heart rate (HR), collected from six community-based cohort studies (64 968 observations) with those from six databases of reflex syncope patients (6516 observations), subdivided by age decades and sex.

RESULTS

Overall, in male individuals with reflex syncope, SBP (-3.4 mmHg) and PP (-9.2 mmHg) were lower and DBP (+2.8 mmHg) and HR (+5.1 bpm) were higher than in the general population; the difference in SBP was higher at ages above 60 years. In female individuals, PP (-6.0 mmHg) was lower and DBP (+4.7 mmHg) and HR (+4.5 bpm) were higher than in the general population; differences in SBP were less pronounced, becoming evident only above 60 years. Compared with male individuals, SBP in female individuals exhibited slower increase until age 40 years, and then demonstrated steeper increase that continued throughout remaining life.

CONCLUSION

The patients prone to reflex syncope demonstrate a different resting cardiovascular haemodynamic profile as compared with a general population, characterized by lower SBP and PP, reflecting reduced venous return and lower stroke volume, and a higher HR and DBP, suggesting the activation of compensatory mechanisms. Our data contribute to a better understanding why some individuals with similar demographic characteristics develop reflex syncope and others do not.

VIDEO ABSTRACT

http://links.lww.com/HJH/B580.

Frequent occurrence of postbreakfast syncope due to carotid sinus syndrome after surgery for hypopharyngeal cancer: A case report

RATIONALE

Syncope often occurs in patients with advanced head and neck cancers due to the stimulation of the autonomic nervous system by the tumor. Here, we describe a case of frequent syncopal episodes after laryngopharyngectomy for hypopharyngeal cancer. As all syncopal episodes were observed during the forenoon, we also evaluated the heart rate variability using ambulatory electrocardiography to determine why the syncopal episodes occurred during a specified period of the day.

PATIENT CONCERNS

A 73-year-old Japanese man who underwent laryngopharyngectomy for recurrent hypopharyngeal cancer started experiencing frequent episodes of loss of consciousness that occurred during the same time period (10:00-12:00). He had never experienced syncopal episodes before the operation. From 23 to 41 days postoperatively, he experienced 9 syncopal episodes that occurred regardless of his posture.

DIAGNOSES

Pharyngo-esophagoscopy revealed an anastomotic stricture between the free jejunum graft and the upper esophagus. Swallowing videofluoroscopy confirmed the dilatation of the jejunal autograft and a foreign body stuck on the oral side of the anastomosis. Contrast-enhanced computed tomography revealed that the carotid artery was slightly compressed by the edematous free jejunum. The patient was diagnosed with carotid sinus syndrome (CSS) as the free jejunum was dilated when consuming breakfast, which may have caused carotid sinus hypersensitivity and induced a medullary reflex.

INTERVENTIONS

Administration of disopyramide was effective in preventing syncope. Heart rate variability analysis using ambulatory electrocardiography showed that parasympathetic dominancy shifted to sympathetic dominancy during 10:00 to 12:00. The significant time regularity of the syncopal episodes may have been affected by modified diurnal variation in autonomic tone activity.

OUTCOMES

After the surgical release and re-anastomosis of the pharyngoesophageal stenosis via an open-neck approach, no recurrent episodes of syncope were reported.

LESSONS

We reported a case of frequent syncopal episodes limited to the forenoon due to CSS after surgery for hypopharyngeal carcinoma. The patient was treated with anticholinergics followed by the release and re-anastomosis of the pharyngoesophageal stenosis. When syncope occurs after surgery for head and neck lesions, CSS due to postoperative structural changes should be considered as a differential diagnosis of syncope.

Are women really more affected by vasovagal syncope than men?

It is commonly reported that vasovagal syncope (VVS) is more frequent in women. Presently, this issue has never been investigated. The purpose of this review was to evaluate, through an extensive review of the literature, whether women are really more affected by VVS than men. The gender distribution was investigated in individuals with classical and nonclassical VVS. The database PubMed was searched using the terms 'syncope', 'vasovagal syncope', 'neurally mediated syncope' and 'tilt testing'. Twelve studies dealing with classical and 75 with nonclassical VVS were eligible. In the individuals with classical (N = 1861) and nonclassical VVS (N = 9696), a trend towards a greater percentage of women emerged (P = 0.14 and 0.07, respectively). In the total population with VVS (N = 11 557), the percentage of women was significantly higher than that of men (58 versus 42%, P = 0.03). Most of the individuals were young or middle-aged. In 84% of the studies, the percentage of women was greater than that of men. A separate analysis was carried out in older VVS patients (≥60 years) and only two studies were eligible to be evaluated. Considering that almost all the studies were carried out in the western nations, where the number of men and women is almost superimposable until the age of 65 years and a bias by gender has never been reported in the management of VVS, these data strongly suggest that young and middle-aged women are more affected by VVS than their male counterparts. At present, data are too scant to draw a definitive conclusion in older VVS patients.

SARS-CoV-2 infection associated with micturition syncope: Our experience with 4 case reports

RATIONALE

Syncope is described as the loss of consciousness and postural muscle tone with a short duration and fast onset. Micturition syncope can be caused by abnormal vasovagal response or by the dysfunction of the blood pressure regulating mechanism, which occurs before, during, or immediately after urination.

PATIENT CONCERNS

We present 4 cases of COVID-19 hospitalized in the Department of Infectious Diseases of the Academic Emergency Hospital Sibiu, Romania, cases that presented micturition syncope.

DIAGNOSES

During hospitalization, patients confirmed with SARS-Cov-2 infection using real time reverse transcriptase-polymerase chain reaction (RT-PCR) assay, presented micturition syncope in different stages of the infection (at the beginning and in the second week of evolution).

INTERVENTIONS

Other causes of syncope such as adrenal insufficiency secondary to corticosteroids treatment, cardiac rhythm disorders, neurological impairment, dehydration, vasoactive medication, malignancies, pulmonary hypertension and coughing were excluded. The treatment of SARS-CoV-2 infection was performed following the local and national guidelines.

OUTCOMES

The clinical course of all 4 patients diagnosed with COVID-19 and micturition syncope was favorable. To our knowledge, micturition syncope in COVID-19 patients has yet not been reported by other authors.

LESSONS

To our knowledge, micturition syncope associated with the evolution of COVID-19, has yet not been reported by other authors.

Neurohormones in the Pathophysiology of Vasovagal Syncope in Adults

Vasovagal syncope (VVS) is the most common cause of syncope across all age groups. Nonetheless, despite its clinical importance and considerable research effort over many years, the pathophysiology of VVS remains incompletely understood. In this regard, numerous studies have been undertaken in an attempt to improve insight into the evolution of VVS episodes and many of these studies have examined neurohormonal changes that occur during the progression of VVS events primarily using the head-up tilt table testing model. In this regard, the most consistent finding is a marked increase in epinephrine (Epi) spillover into the circulation beginning at an early stage as VVS evolves. Reported alterations of circulating norepinephrine (NE), on the other hand, have been more variable. Plasma concentrations of other vasoactive agents have been reported to exhibit more variable changes during a VVS event, and for the most part change somewhat later, but in some instances the changes are quite marked. The neurohormones that have drawn the most attention include arginine vasopressin [AVP], adrenomedullin, to a lesser extent brain and atrial natriuretic peptides (BNP, ANP), opioids, endothelin-1 (ET-1) and serotonin. However, whether some or all of these diverse agents contribute directly to VVS pathophysiology or are principally a compensatory response to an evolving hemodynamic crisis is as yet uncertain. The goal of this communication is to summarize key reported neurohumoral findings in VVS, and endeavor to ascertain how they may contribute to observed hemodynamic alterations during VVS.

Complete atrioventricular dissociation and sinus arrest after pheochromocytoma resection

INTRODUCTION

Although preoperative bradycardia has been reported in several pheochromocytoma cases, postoperative bradycardia has not. This is the first case report of complete atrioventricular dissociation and sinus arrest occurring after pheochromocytoma resection.

CASE PRESENTATION

A 38-year-old woman was referred for a left adrenal incidentaloma. Twenty-four hour urinary collection showed elevated noradrenaline. Iodine-123-meta-iodobenzylguanidine scintigraphy showed high tracer uptake in the left adrenal region. Open left adrenalectomy was performed, and histopathological examination confirmed the diagnosis of pheochromocytoma. Thirty minutes following surgery, complete atrioventricular dissociation and sinus arrest developed. Vagal reflex attenuation due to decreased noradrenaline after tumor removal and perioperative pain and fear were believed to be the causes. A temporary pacemaker was implanted to prevent sudden death due to vagal overstimulation.

CONCLUSION

Vagal reflex attenuation after pheochromocytoma resection can result in complete atrioventricular dissociation and sinus arrest. Adequate preoperative preparation and close monitoring during and after surgery are imperative.

The Search for the Genes of Vasovagal Syncope

Only humans faint, and not all do so. Syncope tends to recur, and the predisposition to syncope can persist over many decades. Observations such as these have suggested that there may be a genetic predisposition to vasovagal syncope. It seems to have a high prevalence in some families; having a parent who faints increases the likelihood of an offspring fainting, and this is increased even further if both biological parents faint. Numerous studies have correlated a number of genotypes with positive tilt tests. However, the control subjects are usually those who faint, but have negative tilt tests, making the conclusions about association with the clinical phenotype less certain. Twin studies, highly focused genome-wide association studies, and gene duplicate studies all suggest there are sites in the genome that associate with vasovagal syncope, although the specific genes, pathways, and proteins are unknown. A recent large, candidate gene study of kindreds with high, multigenerational prevalence of the vasovagal syncope identified 3 genes that associate with vasovagal syncope. Our understanding of the genetic correlates of vasovagal syncope is in its infancy, with much to be understood.

Associations of mortality with own blood pressure using son's blood pressure as an instrumental variable

High systolic blood pressure (SBP) causes cardiovascular disease (CVD) and is associated with mortality from other causes, but conventional multivariably-adjusted results may be confounded. Here we used a son’s SBP (>1 million Swedish men) as an instrumental variable for parental SBP and examined associations with parents’ cause-specific mortality, avoiding reverse causation. The hazard ratio for CVD mortality per SD (10.80 mmHg) of SBP was 1.49 (95% CI: 1.43, 1.56); SBP was positively associated with coronary heart disease and stroke. SBP was also associated positively with all-cause, diabetes and kidney cancer mortality, and negatively with external causes. Negative associations with respiratory-related mortality were probably confounded by smoking. Hazard ratios for other causes were imprecise or null. Diastolic blood pressure gave similar results to SBP. CVD hazard ratios were intermediate between those from conventional multivariable studies and Mendelian randomization and stronger than those from clinical trials, approximately consistent with an effect of exposure duration on effect sizes. Plots of parental mortality against offspring SBP were approximately linear, supporting calls for lower SBP targets. Results suggest that conventional multivariable analyses of mortality and SBP are not substantially confounded by reverse causation and confirm positive effects of SBP on all-cause, CVD and diabetes mortality.

Atypical Prodromal Symptoms Help to Distinguish Patients With Psychogenic Nonsyncopal Collapse Among Youth Referred for Fainting

BACKGROUND

Distinguishing patients with psychogenic nonsyncopal collapse (PNSC), a conversion disorder that resembles syncope, can pose a difficult clinical challenge. Using the open-ended question "what does it feel like to faint?," the present study aimed to characterize how patients with PNSC perceive and communicate the prodromal symptoms associated with their attacks by comparing narratives between patients with PNSC and those with syncope.

METHODS

During a 42-month database-type study of tilt-table diagnoses, all patients with a history of fainting were asked the open-ended question. Symptom descriptions were compared, qualitatively and quantitatively, between patients with PNSC and those with tilt-induced syncope (n = 121 in both cohorts).

RESULTS

Twenty-nine patients (24%) diagnosed with PNSC and eight (6.6%) diagnosed with syncope either denied having any prodromal symptoms or could not recall any symptoms (P < 0.001). Among patients who reported prodromal symptoms, patient narratives led to the formation of 26 symptom categories. Symptom frequencies differed between cohorts in 19 of the symptom categories (each P value <0.05). Qualitative differences in the descriptions of symptoms were often present, even when symptom frequencies did not differ. More patients with PNSC described atypical symptoms than patients with syncope, 54 of 92 (58.7%) versus eight of 113 (7.1%), P < 0.001.

CONCLUSIONS

Symptom narratives can help to distinguish patients with PNSC from those with syncope. The use of a single, open-ended question as a screening tool for conversion disorder has immediate clinical relevance because it can be instituted easily in a busy clinical setting.

Carotid Sinus Nerve: A Comprehensive Review of Its Anatomy, Variations, Pathology, and Clinical Applications

The carotid sinus nerve branches off the glossopharyngeal nerve just after its appearance from the jugular foramen, descends along the internal carotid artery, and enters the carotid sinus. There have been many studies of the pathway and the course of the carotid sinus nerve and its communications with surrounding nerves. The intercommunication is exceedingly complicated. Acknowledgment of its anatomic diversity can be important in specific operations dealing with this area. Herein we review the anatomy, variations, pathology, and clinical applications of the carotid sinus nerve.

Acceleration Index Predicts Efficacy of Orthostatic Training on Vasovagal Syncope in Children

OBJECTIVE

To explore the value of the acceleration index as a predictor of therapeutic response to orthostatic training in children with vasovagal syncope (VVS).

STUDY DESIGN

Thirty-three children with VVS were recruited and treated with orthostatic training. The therapeutic response of each patient was evaluated after 3 months of treatment. A Pearson correlation was calculated between the acceleration index and the severity of VVS. The value of the acceleration index in predicting the therapeutic response to orthostatic training was assessed by analysis of the receiver operating characteristic curve.

RESULTS

Among the 33 children with VVS, 20 were found to be responders and the remaining were nonresponders. The mean acceleration index was significantly lower in responders compared with nonresponders (21.10 ± 6.61 vs 31.36 ± 9.00; P = .001) and it was negatively correlated with positive response time in the head-up tilt test, with systolic blood pressure and with diastolic blood pressure at positive response time in the head-up tilt test (P < .05). The receiver operating characteristic curve for the predictive value of the acceleration index showed that the area under the curve was 0.827 (95% CI, 0.676-0.978; P = .002), and a cutoff value of the acceleration index of 26.77 yielded a sensitivity of 85.0% and a specificity of 69.2%.

CONCLUSIONS

The acceleration index may be useful for predicting the efficacy of orthostatic training on VVS in children.

The Fainting Assessment Inventory: A 10-Item Instrument Developed to Screen for Psychogenic Nonsyncopal Collapse Among Youth Referred for Syncope

The conversion disorder that appears like syncope is common but poorly recognized. The study aimed to develop and validate a brief, clinician-administered screening tool to discriminate psychogenic nonsyncopal collapse (PNSC) among young patients referred for fainting. Consecutive patients with PNSC and with syncope (15.4 ± 2.2 years) completed a 92-item inventory highlighting features typical of PNSC and neurally mediated syncope (n = 35, each cohort). Fourteen items were retained and revised and then administered to new cohorts ultimately diagnosed with PNSC or syncope (n = 40, each cohort). Further revision led to a 10-item Fainting Assessment Inventory (FAI-10). Scoring the syncope ratings positively and the PNSC ratings negatively, median scores differed between cohorts with PNSC and with syncope (-6 vs. 7; p < 0.001). Diagnostic sensitivity (0.95), specificity (0.875), positive predictive value (0.889), negative predictive value (0.93), and area under the curve (0.973) were calculated. The FAI-10 furthers clinicians' ability to distinguish various forms of transient loss of consciousness.

Dangerous noodle: A case of swallowing syncope and a review of 122 cases from the literature

Swallowing syncope is a rare medical condition. Even though it has been known as a neurally mediated syncope, the definitive mechanism of this condition remains unclear. We show in this study an additional case of swallowing syncope and review the 122 reported cases from the literature. A 47-year-old Japanese man had been suffering from recurrent syncopal attacks, when he fainted immediately after swallowing. Holter electrocardiogram monitoring demonstrated a sinus pause (maximum R-R interval of 3.8 seconds) after he swallowed a noodle quickly. A permanent pacemaker was implanted because the frequency of syncope increased.

A New Diagnostic Approach to the Adult Patient with Acute Dizziness

BACKGROUND

Dizziness, a common chief complaint, has an extensive differential diagnosis that includes both benign and serious conditions. Emergency physicians must distinguish the majority of patients with self-limiting conditions from those with serious illnesses that require acute treatment.

OBJECTIVE OF THE REVIEW

This article presents a new approach to diagnosis of the acutely dizzy patient that emphasizes different aspects of the history to guide a focused physical examination with the goal of differentiating benign peripheral vestibular conditions from dangerous posterior circulation strokes in the emergency department.

DISCUSSION

Currently, misdiagnoses are frequent and diagnostic testing costs are high. This relates in part to use of an outdated, prevalent, diagnostic paradigm. The traditional approach, which relies on dizziness symptom quality or type (i.e., vertigo, presyncope, or disequilibrium) to guide inquiry, does not distinguish benign from dangerous causes, and is inconsistent with current best evidence. A new approach divides patients into three key categories using timing and triggers, guiding a differential diagnosis and targeted bedside examination protocol: 1) acute vestibular syndrome, where bedside physical examination differentiates vestibular neuritis from stroke; 2) spontaneous episodic vestibular syndrome, where associated symptoms help differentiate vestibular migraine from transient ischemic attack; and 3) triggered episodic vestibular syndrome, where the Dix-Hallpike and supine roll test help differentiate benign paroxysmal positional vertigo from posterior fossa structural lesions.

CONCLUSIONS

The timing and triggers diagnostic approach for the acutely dizzy patient derives from current best evidence and offers the potential to reduce misdiagnosis while simultaneously decreases diagnostic test overuse, unnecessary hospitalization, and incorrect treatments.

Association Between Baseline Blood Pressures, Heart Rates, and Vasovagal Syncope in Children and Adolescents

BACKGROUND

Vasovagal syncope is the most common cause of syncope in children and adults, accounting for 50-66% of unexplained syncope. There are no studies establishing the relationship between syncope, baseline heart rate, and blood pressure.

OBJECTIVE

To identify a possible association between baseline blood pressure and heart rate with syncope.

DESIGN/METHODS

We conducted a questionnaire-based chart review study. A questionnaire was distributed to the guardian of children between eight and 18 years of age who attended the Pediatric Ambulatory Care Clinic at Flushing Hospital Medical Center. Based on the responses in the questionnaire, subjects were classified either as cases (positive for syncope) or controls (negative for syncope). Children and adolescents with neurological, cardiac, or any medical condition that can cause syncopal episodes were excluded from the study. Data collected from the questionnaire included age, gender, ethnicity, medical history, family history of syncope, and the amount of salt used in food. Anthropometric and vital signs for the current visit (height, weight, BMI, blood pressure, and heart rate) and vital signs from two previous visits were collected from electronic medical records. The data was analyzed using t-test and chi-square test with Microsoft Excel software (Microsoft Office Standard, v. 14, Microsoft; 2010); p<0.05 was considered significant.

RESULTS

A total of 197 subjects were included in this study. There were 18 cases and 179 controls. Of the cases, (4/18) 22.2% were more likely to have a systolic blood pressure lower than the 10th percentile for their gender, age, and height as compared with controls (7/179) 3.9%, p = 0.003. The subjects with a history of syncope were more likely to add salt to their food (p = 0.004). There were no significant differences between cases and controls for age, gender, ethnicity between cases and controls for systolic blood pressure. No significant difference was observed between the heart rates of cases and controls.

CONCLUSIONS

Children and adolescents with syncope were more likely to have a systolic blood pressure lower than the 10th percentile, and there was no difference in the baseline heart rate. In addition, children with syncope were more likely to add salt to their food.

The heart of epilepsy: Current views and future concepts

Cardiovascular (CV) comorbidities are common in people with epilepsy. Several mechanisms explain why these conditions tend to co-exist including causal associations, shared risk factors and those resulting from epilepsy or its treatment. Various arrhythmias occurring during and after seizures have been described. Ictal asystole is the most common cause. The converse phenomenon, arrhythmias causing seizures, appears extremely rare and has only been reported in children following cardioinihibitory syncope. Arrhythmias in epilepsy may not only result from seizure activity but also from a shared genetic susceptibility. Various cardiac and epilepsy genes could be implicated but firm evidence is still lacking. Several antiepileptic drugs (AEDs) triggering conduction abnormalities can also explain the co-existence of arrhythmias in epilepsy. Epidemiological studies have consistently shown that people with epilepsy have a higher prevalence of structural cardiac disease and a poorer CV risk profile than those without epilepsy. Shared CV risk factors, genetics and etiological factors can account for a significant part of the relationship between epilepsy and structural cardiac disease. Seizure activity may cause transient myocardial ischaemia and the Takotsubo syndrome. Additionally, certain AEDs may themselves negatively affect CV risk profile in epilepsy. Here we discuss the fascinating borderland of epilepsy and cardiovascular conditions. The review focuses on epidemiology, clinical presentations and possible mechanisms for shared pathophysiology. It concludes with a discussion of future developments and a call for validated screening instruments and guidelines aiding the early identification and treatment of CV comorbidity in epilepsy.

A New Approach to the Diagnosis of Acute Dizziness in Adult Patients

Dizziness is a common chief complaint in emergency medicine. The differential diagnosis is broad and includes serious conditions, such as stroke, cardiac arrhythmia, hypovolemic states, and acute toxic and metabolic disturbances. Emergency physicians must distinguish the majority of patients who suffer from benign self-limiting conditions from those with serious illnesses that require acute treatment. Misdiagnoses are frequent and diagnostic test costs high. The traditional approach does not distinguish benign from dangerous causes and is not consistent with best current evidence. This article presents a new approach to the diagnosis of acutely dizzy patients that highly leverages the history and the physical examination.

Comparison of semiologies between tilt-induced psychogenic nonsyncopal collapse and psychogenic nonepileptic seizures

We sought to characterize the clinical features of tilt-induced psychogenic nonsyncopal collapse (PNSC) from a cohort of young patients and to compare the semiologies between PNSC and EEG-confirmed psychogenic nonepileptic seizures (PNES). A PNSC diagnosis was made if a clinical event occurred during tilt-table testing that the patient regarded as fainting, but neither hypotension nor EEG changes were present. A diagnosis of PNSC was made in 17.6% of all patients referred during the 15-month study period. Cohorts with psychogenic nonsyncopal collapse (n=40) and PNES (n=40) did not differ in age (15.5±2.2 versus 14.6±2.7, p=.11) or female gender (80% versus 72.5%, p=.43). Psychogenic nonsyncopal collapse events were briefer than PNES events (median: 45 versus 201.5s, p<.001). Negative motor signs (head drop, body limpness) predominated in PNSC (85% versus 20%, p<.001), while the positive motor signs of convulsion occurred more often with PNES (90% versus 30%, p<.001). Behavioral arrest (25% versus 32.5%, p=.46) and eye closure (85% versus 72.5%, p=.21) did not differ between PNSC and PNES. Patients with PNSC were more likely to be tearful before (30% versus 7.5%, p=.02) and after (62.5% versus 7.5%, p<.001) an event. In conclusion, although overlap exists, the features of PNSC generally appear similar to neurally mediated syncope, while the features of PNES generally appear similar to epileptic seizures. Psychogenic nonsyncopal collapse and PNES likely represent similar disorders that differ primarily by clinical semiologies and referral patterns.

Catheter Ablation as a Treatment for Vasovagal Syncope: Long-Term Outcome of Endocardial Autonomic Modification of the Left Atrium

Background

Autonomic modification through catheter ablation of ganglionated plexi (GPs) in the left atrium has been reported previously as a treatment for vasovagal syncope. This study aimed to observe the long‐term outcome in a larger cohort.

Methods and Results

A total of 57 consecutive patients (aged 43.2±13.4 years; 35 women) with refractory vasovagal syncope were enrolled, and high‐frequency stimulation and anatomically guided GP ablation were performed in 10 and 47 cases, respectively. A total of 127 GP sites with positive vagal response were successfully elicited and ablated, including 52 left superior, 19 left lateral, 18 left inferior, 27 right anterior, and 11 right inferior GPs. During follow‐up of 36.4±22.2 months (range 12–102 months), 52 patients (91.2%) remained free from syncope. Prodromes recurred in 16 patients. No statistical differences were found between the high‐frequency stimulation and anatomically guided ablation groups in either freedom from syncope (100% versus 89.4%, P=0.348) or recurrent prodromes (50% versus 76.6%, P=0.167). The deceleration capacity, heart rate, and heart rate variability measurements demonstrated a reduced vagal tone lasting for at least 12 months after the procedure, with improved tolerance of repeated head‐up tilt testing. No complications were observed except for transient sinus tachycardia that occurred in 1 patient.

Conclusions

Left atrial GP ablation showed excellent long‐term clinical outcomes and might be considered as a therapeutic option for patients with symptomatic vasovagal syncope.

TiTrATE: A Novel, Evidence-Based Approach to Diagnosing Acute Dizziness and Vertigo

Diagnosing dizziness can be challenging, and the consequences of missing dangerous causes, such as stroke, can be substantial. Most physicians use a diagnostic paradigm developed more than 40 years ago that focuses on the type of dizziness, but this approach is flawed. This article proposes a new paradigm based on symptom timing, triggers, and targeted bedside eye examinations (TiTrATE). Patients fall into 1 of 4 major syndrome categories, each with its own differential diagnosis and set of targeted examination techniques that help make a specific diagnosis. Following an evidence-based approach could help reduce the frequency of misdiagnosis of serious causes of dizziness. In the spirit of the flipped classroom, the editors of this Neurologic Clinics issue on emergency neuro-otology have assembled a collection of unknown cases to be accessed electronically in multimedia format. By design, cases are not linked with specific articles, to avoid untoward cueing effects for the learner. The cases are real and are meant to demonstrate and reinforce lessons provided in this and subsequent articles. In addition to pertinent elements of medical history, cases include videos of key examination findings.

Venepuncture during head-up tilt testing in patients with suspected vasovagal syncope – implications for the test protocol

BACKGROUND AND PURPOSE

Head-up tilt (HUT) testing is a widely used diagnostic tool in patients with suspected vasovagal syncope (VVS). However, no gold standard exists for this examination and the various protocols used have a limited sensitivity and specificity. Our aim was to determine the sensitivity of a sequential HUT testing protocol including venepuncture (VP) and sublingual nitroglycerin application.

METHODS

This was a retrospective analysis of the diagnostic gain of a sequential HUT testing protocol including VP applied 10 min after the start of HUT testing and sublingual application of nitroglycerin 20 min after the start of the test protocol in 106 patients with a final diagnosis of VVS. The sensitivity of the test protocol was compared between patients with positive and negative history for VP induced VVS.

RESULTS

Overall, pre-syncope or syncope occurred in 68 patients (64.2%). Only 17% of all patients fainted spontaneously within 10 min of passive HUT. Another 39.6% fainted within 20 min. Application of nitroglycerin after 20 min of HUT evoked syncope in another 7.5% until the end of 45 min of HUT. The sensitivity of the test protocol for evoking (pre-)syncope was 94.4% in patients with a positive history for VP associated VVS and 58% in patients with a negative history (P < 0.01**); 85.7% of patients with a positive history and 42.9% of patients with a negative history fainted within 20 min of HUT testing (P < 0.01**).

CONCLUSIONS

Implementation of VP in sequential HUT testing protocols allows the sensitivity of HUT testing to be increased, especially in patients with a positive history for VP associated VVS.

Biomolecular mechanisms in varicose veins development

Varicose veins (VVs) can be described as tortuous and dilated palpable veins, which are more than 3 mm in diameter. They are one of the clinical presentations of chronic venous disorders, which are a significant cause of morbidity. The prevalence of VVs has been estimated at 25-33% in women and 10-20% in men and is still increasing at an alarming rate. Family history, older age, female, pregnancy, obesity, standing occupations, and a history of deep venous thrombosis are the predominant risk factors. A great amount of factors are implicated in the pathogenesis of VVs, including changes in hydrostatic pressure, valvular incompetence, deep venous obstruction, ineffective function of calf muscle pump, biochemical and structural alterations of the vessel wall, extracellular matrix abnormalities, impaired balance between growth factors or cytokines, genetic alterations, and several other mechanisms. Nevertheless, the issue of pathogenesis in VVs is still not completely known, even if a great progress has been made in understanding their molecular basis. This kind of studies appears promising and should be encouraged, and perhaps the new insight in this matter may result in targeted therapy or possibly prevention.

Sympathetic dysfunction in vasovagal syncope and the postural orthostatic tachycardia syndrome

Orthostatic intolerance is the inability to tolerate the upright posture and is relieved by recumbence. It most commonly affects young women and has a major impact on quality of life and psychosocial well-being. Several forms of orthostatic intolerance have been described. The most common one is the recurrent vasovagal syncope (VVS) phenotype which presents as a transient and abrupt loss of consciousness and postural tone that is followed by rapid recovery. Another common type of orthostatic intolerance is the postural orthostatic tachycardia syndrome (POTS) which is characterized by an excessive rise in heart rate upon standing and is associated with symptoms of presyncope such as light-headedness, fatigue, palpitations, and nausea. Maintenance of arterial pressure under condition of reduced central blood volume during the orthostasis is accomplished in large part through sympathetic efferent nerve traffic to the peripheral vasculature. Therefore sympathetic nervous system (SNS) dysfunction is high on the list of possible contributors to the pathophysiology of orthostatic intolerance. Investigations into the role of the SNS in orthostatic intolerance have yielded mixed results. This review outlines the current knowledge of the function of the SNS in both VVS and POTS.

Blood pressure levels and risk of cardiovascular events and mortality in type-2 diabetes: cohort study of 34 009 primary care patients

OBJECTIVE

The optimal blood pressure (BP) in persons with type-2 diabetes is debated. We investigated shapes of the associations of SBP and DBP levels with risk of cardiovascular events and mortality in a large primary care-based sample of diabetic patients.

METHODS

We investigated all 34 009 consecutive cardiovascular disease-free type-2 diabetes patients aged 35 years or older (mean age 64 years) at 84 primary care centers in central Sweden between 1999 and 2008. We followed this cohort until the end of 2009 in national registries for the incidence of major cardiovascular events (a composite endpoint of myocardial infarction, stroke, heart failure, or cardiovascular mortality) or total mortality.

RESULTS

During up to 11 years of follow-up, 6344 patients (18.7%) had a first cardiovascular event, and 6235 died (18.3%). The associations of annually updated SBP and DBP with risk of major cardiovascular events were U-shaped. The lowest risk of cardiovascular events was observed at a SBP of 135-139 mmHg and a DBP of 74-76 mmHg, and the lowest mortality risk at a SBP of 142-150 mmHg and a DBP of 78-79 mmHg, in both antihypertensive drug-untreated and drug-treated persons.

CONCLUSION

In a large primary care-based sample of patients with type-2 diabetes, associations of SBP and DBP with risk of major cardiovascular events and mortality were U-shaped. This may have implications for risk stratification of persons with diabetes.

Regadenoson in Europe: first-year experience of regadenoson stress combined with submaximal exercise in patients undergoing myocardial perfusion scintigraphy

Purpose

Regadenoson was approved for clinical use in Europe in 2011. Since then, it has become the default form of stress at our institution. We have assessed the side-effect profile and tolerability of regadenoson in patients undergoing clinically indicated myocardial perfusion scintigraphy between July 2011 and July 2012.

Methods

Clinical, stress and imaging data were recorded prospectively. Symptoms during stress were recorded and defined as mild, moderate or severe. An adverse event was defined as any symptom that persisted for more than 30 min or that required investigation or treatment.

Results

Of 1,764 consecutive patients, 1,581 (90 %) received regadenoson combined with submaximal exercise unless contraindicated. Symptoms were common (63 %) but transient and well-tolerated. The severity of symptoms was recorded in most patients as mild (84 %). Dyspnoea (36 %) and chest discomfort (12 %) were the commonest side effects. Adverse events were reported in eight patients (0.5 %), thought to be vasovagal in seven of these. All patients recovered fully without sequelae. There were no deaths, myocardial infarction or hospital admissions. Regadenoson stress was performed in 206 patients (12 %) with asthma or chronic obstructive pulmonary disease (COPD) without bronchospasm or any other major side effect.

Conclusion

We studied the symptom profile of regadenoson in the largest European cohort to date. Regadenoson combined with submaximal exercise was well tolerated, notably also in patients with asthma or COPD. The majority of regadenoson-related adverse events were vasovagal episodes without sequelae.

The semiology of tilt-induced psychogenic pseudosyncope

OBJECTIVES

To provide a detailed semiology to aid the clinical recognition of psychogenic pseudosyncope (PPS), which concerns episodes of apparent transient loss of consciousness (TLOC) that mimic syncope.

METHODS

We analyzed all consecutive tilt-table tests from 2006 to 2012 showing proven PPS, i.e., apparent TLOC had occurred without EEG changes or a decrease in heart rate (HR) or blood pressure (BP). We analyzed baseline characteristics, video data, EEG, ECG, and continuous BP measurements on a 1-second time scale. Data were compared with those of 69 cases of tilt-induced vasovagal syncope (VVS).

RESULTS

Of 800 tilt-table tests, 43 (5.4%) resulted in PPS. The majority (74%) were women. The median duration of apparent TLOC was longer in PPS (44 seconds) than in VVS (20 seconds, p < 0.05). During the event, the eyes were closed in 97% in PPS but in only 7% in VVS (p < 0.0001). A sudden head drop or moving down the tilt table was more common in PPS than in VVS (p < 0.01), but jerking movements occurred more frequently in VVS (p < 0.0001). In PPS, both HR and BP increased before and during apparent TLOC (p < 0.0001).

CONCLUSIONS

PPS is clinically distinct from VVS and can be diagnosed accurately with tilt-table testing and simultaneous EEG monitoring. Compared with VVS, eye closure during the event, long periods of apparent TLOC, and high HR and BP are highly specific for PPS. Improved understanding of the semiology of PPS as a clinical entity is vital to ensure accurate diagnosis.

Right insular atrophy in neurocardiogenic syncope: a volumetric MRI study

BACKGROUND AND PURPOSE

Alterations in the central autonomic network are hypothesized to play a role in the pathophysiologic mechanism underlying neurocardiogenic syncope; however, few data are available regarding the structural changes of the brain in this condition. We used voxel-based morphometry and regional volumetry to identify possible neuroanatomic correlates.

MATERIALS AND METHODS

We prospectively studied 32 patients with neurocardiogenic syncope with a positive response to the head-up tilt test and 32 controls who had no history of syncope. We used voxel-based morphometry to compare GM volumes between patients and controls. In addition, regional volumes of structures known to be included in the central autonomic network were measured and compared between the groups. Correlation analyses were also performed between clinical variables and anatomic data.

RESULTS

Voxel-based morphometry showed a significant GM volume reduction in the right insular cortex in patients with neurocardiogenic syncope compared with controls (corrected P = .033). Regional volumetry showed a significant reduction of right insular volumes in patients compared with controls (P = .002, MANCOVA). Smaller right insular volumes in patients with neurocardiogenic syncope were related to larger drops in systolic (P = .020) and diastolic (P = .003) blood pressures during the head-up tilt test.

CONCLUSIONS

We observed a novel finding of right insular atrophy in patients with neurocardiogenic syncope with a positive response to the head-up tilt test, implicating the role of right insular dysfunction in the pathophysiologic mechanism underlying neurocardiogenic syncope. Our findings further support the hypothesis that right insular dysfunction may cause a decrease in sympathetic activity and a reciprocal increase in parasympathetic activity, leading to syncope.

Recurrent laughter-induced syncope

INTRODUCTION

Syncope is a common presenting complaint in Neurology clinics or Emergency departments, but its causes are sometimes difficult to diagnose. Apart from vasovagal attacks, other benign, neurally mediated syncopes include "situational" syncopes, which occur after urination, coughing, swallowing, or defecation.

CASE REPORT

A healthy 42-year-old male patient presented to the neurology clinic with a long history of faints triggered by spontaneous laughter, especially after funny jokes. Physical and neurological examination, and electroencephalography and magnetic resonance imaging were unremarkable. There was no evidence to suggest cardiogenic causes, epilepsy, or cataplexy and a diagnosis of laughing syncope was made.

CONCLUSIONS

Laughter-induced syncope is usually a single event in the majority of cases, but may present as recurrent attacks as in our case. Some cases occur in association with underlying neurological conditions. Prognosis is good in the case of neurally mediated attacks. Laughter may not be recognized by physicians as a cause of syncope, which may lead to unnecessary investigations or misdiagnosis, and affect patients' quality of life.

Underlying diseases in syncope of children in China

Background

Syncope accounts for about 1–2% of emergency department visits, but the etiology in many patients with syncope is unclear. Recently, with the use of the head-up tilt test (HUT), the number of patients with unexplained syncope (UPS) has been decreasing; however, the spectrum of underlying diseases of syncope in children is unclear. This retrospective study aimed to analyze the spectrum of underlying diseases in children with syncope.

Material/Methods

This multi-center clinical study consisted of 888 children (417 males, 471 females, aged 5–18 yrs, median age 12.0±3.0 yrs) with syncope who came from Beijing city, Hunan province, Hubei province and Shanghai from August 1999 to March 2009. The clinical and laboratory data of children were studied and the spectrum of underlying diseases in children with syncope was analyzed.

Results

In 888 children with syncope, 175 (19.7%) had vasovagal syncope (VVS) with vasoinhibitory response, 35 (3.9%) had VVS with cardioinhibitory response, 73 (8.2%) had VVS with mixed response, 286 (32.2%) had postural orthostatic tachycardia syndrome (POTS), 19 (2.1%) had orthostatic hypotension, 7 (0.9%) had situational syncope, 13 (1.5%) had cardiogenic syncope, and 280 (31.5%) had unexplained syncope.

Conclusions

The data suggest that neurally-mediated syncope was the most common cause in children with syncope. POTS and VVS were the most common hemodynamic patterns of neurally-mediated syncope.

Recurrent postural vasovagal syncope: sympathetic nervous system phenotypes

BACKGROUND

The pathophysiology of vasovagal syncope is poorly understood, and the treatment usually ineffective. Our clinical experience is that patients with vasovagal syncope fall into 2 groups, based on their supine systolic blood pressure, which is either normal (>100 mm Hg) or low (70-100 mm Hg). We investigated neural circulatory control in these 2 phenotypes.

METHODS AND RESULTS

Sympathetic nervous testing was at 3 levels: electric, measuring sympathetic nerve firing (microneurography); neurochemical, quantifying norepinephrine spillover to plasma; and cellular, with Western blot analysis of sympathetic nerve proteins. Testing was done during head-up tilt (HUT), simulating the gravitational stress of standing, in 18 healthy control subjects and 36 patients with vasovagal syncope, 15 with the low blood pressure phenotype and 21 with normal blood pressure. Microneurography and norepinephrine spillover increased significantly during HUT in healthy subjects. The microneurography response during HUT was normal in normal blood pressure and accentuated in low blood pressure phenotype (P=0.05). Norepinephrine spillover response was paradoxically subnormal during HUT in both patient groups (P=0.001), who thus exhibited disjunction between nerve firing and neurotransmitter release; this lowered norepinephrine availability, impairing the neural circulatory response. Subnormal norepinephrine spillover in low blood pressure phenotype was linked to low tyrosine hydroxylase (43.7% normal, P=0.001), rate-limiting in norepinephrine synthesis, and in normal blood pressure to increased levels of the norepinephrine transporter (135% normal, P=0.019), augmenting transmitter reuptake.

CONCLUSIONS

Patients with recurrent vasovagal syncope, when phenotyped into 2 clinical groups based on their supine blood pressure, show unique sympathetic nervous system abnormalities. It is predicted that future therapy targeting the specific mechanisms identified in the present report should translate into more effective treatment.

Association of blood pressure in late adolescence with subsequent mortality: cohort study of Swedish male conscripts

OBJECTIVE

To investigate the nature and magnitude of relations of systolic and diastolic blood pressures in late adolescence to mortality.

DESIGN

Nationwide cohort study.

SETTING

General community in Sweden.

PARTICIPANTS

Swedish men (n = 1,207,141) who had military conscription examinations between 1969 and 1995 at a mean age of 18.4 years, followed up for a median of 24 (range 0-37) years.

MAIN OUTCOME MEASURES

Total mortality, cardiovascular mortality, and non-cardiovascular mortality.

RESULTS

During follow-up, 28,934 (2.4%) men died. The relation of systolic blood pressure to total mortality was U shaped, with the lowest risk at a systolic blood pressure of about 130 mm Hg. This pattern was driven by the relation to non-cardiovascular mortality, whereas the relation to cardiovascular mortality was monotonically increasing (higher risk with higher blood pressure). The relation of diastolic blood pressure to mortality risk was monotonically increasing and stronger than that of systolic blood pressure, in terms of both relative risk and population attributable fraction (deaths that could be avoided if blood pressure was in the optimal range). Relations to cardiovascular and non-cardiovascular mortality were similar, with an apparent risk threshold at a diastolic blood pressure of about 90 mm Hg, below which diastolic blood pressure and mortality were unrelated, and above which risk increased steeply with higher diastolic blood pressures.

CONCLUSIONS

In adolescent men, the relation of diastolic blood pressure to mortality was more consistent than that of systolic blood pressure. Considering current efforts for earlier detection and prevention of risk, these observations emphasise the risk associated with high diastolic blood pressure in young adulthood.

Persistence of muscle sympathetic nerve activity during vasovagal syncope

AIMS

To determine whether sympathetic nerve firing to skeletal muscle vasculature is withdrawn during vasovagal syncope (VVS) precipitated by passive graded head-up tilt (HUT) table testing.

METHODS AND RESULTS

We performed passive graded HUT table testing in 18 patients with a history of recurrent postural VVS whom we evaluated during the syncopal event. All patients developed typical VVS during testing. Blood pressure was measured continuously via intra-brachial arterial line. Muscle sympathetic nerve activity (MSNA) was measured using an electrode in the peroneal nerve. Passive graded HUT was then applied. No pharmacological agents were used to provoke syncope. The recording site was maintained through the syncopal event in 10 of 18 patients and we were able to demonstrate persistence of MSNA during syncope in 9. The predominant haemodynamic pattern of syncope in this cohort was mixed--hypotension and bradycardia, with heart rate not falling <40 b.p.m. (n = 10).

CONCLUSION

Our data challenge the established view that the final trigger for human orthostatic vasovagal reactions is sympathetic nervous system inhibition. Efferent sympathetic nerve traffic to the skeletal muscle vasculature was nearly always maintained through the faint. This finding supports an alternative viewpoint, that vasodilator mechanisms underlie the blood pressure fall in VVS.

Vulnerability to simple faints is predicted by regional differences in brain anatomy

Neurocardiogenic syncope (NCS, simple fainting) is a common and typically benign familial condition, which rarely may result in traumatic injury or hypoxic convulsions. NCS is associated with emotional triggers, anxiety states and stress. However, the etiology of NCS, as a psychophysiological process, is poorly understood. We therefore investigated the relationship between NCS and brain anatomy. We studied a non-clinical sample of eighteen individuals with histories characteristic of NCS, and nineteen matched controls who had never fainted. We recorded fainting frequency, resting heart rate variability measures and anxiety levels. Structural T1-weighted magnetic resonance images (MRI) were acquired at 1.5 T. Associations between brain morphometry (regional gray and white matter volumes) and NCS, resting physiology and anxiety were tested using voxel-based morphometry (VBM). Compared to controls, NCS participants had lower regional brain volume within medulla and midbrain (a priori regions of interest). Moreover, across NCS individuals, lower gray matter volume in contiguous regions of left caudate nucleus predicted enhanced parasympathetic cardiac tone, fainting frequency and anxiety levels. Our findings provide preliminary evidence for a hierarchical anatomical basis to NCS. First, differences in the volume of brainstem centers supporting cardiovascular homeostasis may relate to constitutional predisposition to NCS. Second, differences in the structural organization of the caudate nucleus in NCS individuals may relate to fainting frequency via interactions between emotional state and parasympathetic control of the heart. These observations highlight the application of VBM to the identification of neurovisceral mechanisms relevant to psychosomatic medicine and the neuroscience of emotion.

Genetic aspects of vasovagal syncope: a systematic review of current evidence

Knowledge on the aetiology of vasovagal syncope (VVS) is of great importance to optimize its diagnostic and therapeutic options. To unravel the largely unknown pathophysiology, studies on genetic aspects of VVS can be of use. This systematic review on all available literature aims to provide an overview of the current knowledge of VVS genetics. The MEDLINE and EMBASE database were systematically searched for all studies discussing genetic factors as a cause of VVS. Hereditary aspects of VVS were studied in 19 studies. Six studies determined a positive family history in, respectively, 19-90% of the VVS patients. These numbers, however, are not higher than the cumulative incidence of VVS in the general population (35-39%). Four studies examined potential genetic polymorphisms associated with VVS. Only a Gly389 allele was more frequently present in VVS patients with a positive HUT test, although the significance level was set much higher than usual in genetic studies, and this result has not been replicated so far. Knowledge on genetic aspects of VVS could be very useful in clinical practice and research, but the current evidence that it has a genetic basis is not very strong.