Effectiveness of cardioneuroablation in different subtypes of vasovagal syncope

BACKGROUND Cardioneuroablation(CNA)has shown encouraging results in patients with vasovagal syncope(VVS).However,data on different subtypes was scarce.METHODS This observational study retrospectively enrolled 141 patients[mean age:40±18 years,51 males(36.2%)]with the diagnosis of VVS.The characteristics among different types of VVS and the outcomes after CNA were analyzed.RESULTS After a mean follow-up of 4.3±1.5 years,41 patients(29.1%)experienced syncope/pre-syncope events after CNA.Syncope/pre-syncope recurrence significantly differed in each subtype(P=0.04).The cardioinhibitory type of VVS had the lowest recurrence rate after the procedure(n=6,16.7%),followed by mixed(n=26,30.6%)and vasodepressive(n=9,45.0%).Additionally,a significant difference was observed in the analyses of the Kaplan-Meier survival curve(P=0.02).Syncope/pre-syncope burden was significantly reduced after CNA in the vasodepressive type(P<0.01).Vasodepressive types with recurrent syncope/pre-syncope after CNA have a lower baseline deceleration capacity(DC)level than those without(7.4±1.0 ms vs.9.0±1.6 ms,P=0.01).Patients with DC<8.4 ms had an 8.1(HR=8.1,95%CI:2.2-30.0,P=0.02)times risk of syncope/pre-syncope recurrence after CNA compared to patients with DC≥8.4 ms,and this association still existed after adjusting for age and sex(HR=8.1,95%CI:2.2-30.1,P=0.02).CONCLUSIONS Different subtypes exhibit different event-free rates.The vasodepressive type exhibited the lowest event-free rate,but those patients with DC≥8.4 ms might benefit from CNA.

Orthostatic Hypotension: QTc Interval Prolongation during Head-Up Tilt

Background: The QT interval shortens in response to sympathetic stimulation. Head-up tilt-table (HUT) testing is a straightforward way to achieve brisk sympathetic stimulation. There is not enough information about the response of the QT interval to HUT, particularly, in patients with orthostatic hypotension (OH). Objective: Analyse the response of the RR, QT and QTc intervals in patients with OH and reflex syncope (NM) during HUT and find differences between groups. Methods: We reviewed the electrocardiograms and compare the RR and QT/QTc intervals during 1) baseline;2) HUT plus hyperventilation;3) positive test. Results: We studied 137 patients, 62 control group (no syncope and negative HUT). On average, the RR HUT interval was shorter than the resting RR by −171 ± 110.4 ms in controls;−228.6 ± 119.4 ms (NM) and −194 ± (OH) (P Conclusion: Significant differences between the reflex group and the OH during a positive test, the QTc decreased in the NM group, but in the OH population increased. This observation has not been described. We hypothesize that QTc prolongation could reflect autonomic nervous system downregulation and could explain to a degree, the increased mortality in this group.

A Case of Vasovagal Syncope Induced by Tooth Extraction

Background: Vasovagal syncope (VVS) is a neurogenic reflex-mediated fainting episode characterized by sudden, transient, and self-limiting symptoms. While VVS accounts for a significant portion (around 60%) of emergent medical events in dental practice, it remains an underrecognized condition among dental professionals, often misdiagnosed as hypoglycemia, conversion disorder, or epilepsy. This case report describes a VVS episode induced by tooth extraction, aiming to improve dental clinicians’ awareness and diagnostic approach to VVS. Case Presentation: A 35-year-old female visited the dental department in April 2022 with a two-year history of food impaction in the upper right molar. Examination revealed an elongated, discolored, and tender tooth 18, lacking proper occlusion with the opposing tooth. After confirming no contraindications, the tooth was extracted using a minimally invasive technique. Following the procedure, the patient experienced dizziness upon standing;her blood pressure was 69/47 mmHg, and her heart rate was 65 bpm. The nursing staff assisted her to sit as she showed limb weakness, closed eyes, and briefly lost consciousness. Oxygen was administered, and her blood glucose was 6.5. Blood pressure later improved to 124/78 mmHg, with a pulse of 62 bpm. Oral glucose was given, which she vomited, and emergency services were called. Upon arrival, the patient was alert and cooperative. Neurology consultation and imaging (MRI, MRA, and DWI) ruled out cerebral infarction, initially diagnosing a conversion disorder. A subsequent tilt-table test, including sublingual nitroglycerin, induced a marked blood pressure drop and symptoms confirming a diagnosis of vasovagal syncope (VVS). Conclusions: This case shows that preoperative anxiety, fear, and prolonged waiting can trigger vasovagal reflex during tooth extraction, especially in patients with anxiety or cardiac arrhythmias. For such patients, preoperative precautions and intraoperative cardiac monitoring are advised. In cases of VVS, quick actions like monitoring blood pressure, placing the patient in a supine position, providing oxygen, and administering IV fluids or medications like atropine, if necessary, can help stabilize the patient.

Cases Report of Atypical Aortic Dissection

Background: Aortic dissection (AD) is one of the common causes of fatal chest pain in emergency medicine. The main and most common clinical manifestation is pain, with about 90% of patients experiencing sudden persistent, tearing or cutting-like pain in the chest or back. However, there have also been reports of myocardial infarction, heart failure, renal failure, syncope, shock, stroke, paraplegia and other cases. Clinical misdiagnosis is common. Aim: Alert clinicians to aortic dissection with shock and chest tightness as the main clinical presentations. Case Presentation: Report on two cases of aortic dissection with syncope and shock as the main manifestations. Conclusion: Aortic dissection is a highly dangerous cardiovascular emergency with a high mortality rate. In clinical practice, awareness of the clinical manifestations of aortic dissection should be increased. Careful inquiry about medical history, attention to atypical clinical presentations of aortic dissection, thorough physical examination, and comprehensive diagnostic evaluation can improve the success rate of diagnosing aortic dissection.

A Case Report of Recurrent Guillain-Barré Syndrome with Orthostatic Hypotension Syncope as the First Symptom

Guillain⁃Barré syndrome (GBS) is an immune-mediated peripheral neuropathy with acute or subacute onset of flaccid paralysis of the limbs with symmetrical hypesthesia and autonomic nerve involvement [1]. The clinical manifestations of autonomic nerve damage are complex and varied, which may involve extensive or limited autonomic function damage, including abnormalities of the skin, pupil, urinary tract, gastrointestinal tract, cardiovascular system, body temperature, lacrimal and salivary glands, and sexual function, etc. [2], and some patients may even have autonomic nerve damage as the only symptom, which is a variant of GBS and is prone to misdiagnosis or underdiagnosis. Recurrence of GBS is rare, and the manifestations of recurrence are often similar to those of the first symptoms [3], but the patient admitted to our hospital had syncope as the main clinical manifestation of recurrence, which was completely different from that of the first incidence, and syncope is not a common and typical clinical manifestation of GBS, so misdiagnosis is highly likely.

儿童血管迷走性晕厥的诊断与治疗

血管迷走性晕厥（vasovagal syncope,VVS）是儿童不明原因晕厥的主要病因之一[1],以晕厥发作时心动过缓和周围血管舒张为特征。Stewart[2]认为VVS属于急性直立不耐受（acute orthostatic intolerance,AOI）,患者在直立过程中可出现短暂的发作性晕厥或晕厥先兆症状。Bezold-Jarisch反射是目前较为公认引起VVS血流动力学改变的发病机制。在体位变化或长时间维持直立位时,VVS患儿不能快速适应,以致回心血量减少,心室充盈减少,激活压力感受器兴奋交感神经，心室收缩增强，心室过度强烈收缩，形成“排空效应”，激活左心室后下壁压力感受器c纤维，通过Bezold—Jarisch反射，兴奋脑干迷走神经中枢，致使迷走神经兴奋性增高，外周血管扩张，心脏收缩受抑，血压、心率下降，脑血流减少，自主肌张力不能维持而发生晕厥。

候选基因多态性与血管迷走性晕厥相关性研究进展

晕厥是脑血流灌注减少所致的一过性意识丧失,不能维持自主体位。临床引起晕厥的原因众多,血管迷走性晕厥（vasovagal syncope,VVS）是最常见的类型。血管迷走性晕厥的确切发病机制仍不详,目前越来越多的研究支持家族聚集性发病,并根据其发作时主要表现为心率和（或）血压下降的特点,提示存在遗传学机制及异常的心血管反射参与。

进一步关注儿童晕厥的诊治

晕厥是指由于大脑一过性缺血缺氧所致的短暂性意识丧失,多伴有肌张力丧失而不能维持自主体位,是儿科门诊中的常见急症。有15%-25%的儿童及青少年曾经历至少一次晕厥。儿童晕厥的疾病谱主要包括自主神经介导性晕厥、心源性晕厥、脑血管疾病所导致的晕厥以及不明原因晕厥等,自主神经介导性晕厥是儿童晕厥中最常见的疾病,包括血管迷走性晕厥（vasovagal syncope,VVS）、体位性心动过速综合征（postural tachycardia syndrome，POTS）、直立性低血压（orthostatichypotension，OH）等。晕厥反复发作对患儿的身心健康以及学习生活均会造成不良影响。

儿童血管迷走神经性晕厥的发病机制及治疗

晕厥（syncope）是指一过性全脑供血不足导致的短暂意识丧失,常伴有肌张力不能维持而跌倒,特点是发生迅速、一过性、自限性并能够很快完全恢复正常。

我国儿童功能性心血管疾病的研究现状

血管迷走性晕厥（vasovagal syncope,VVS）、体位性心动过速综合征（postural orthostatic tachycardia syndrome,POTS）、直立性低血压（orthostatic hypertension,OH）、直立性高血压（orthostatic hypertension,OHT）及β受体功能亢进等作为常见的儿童功能性心血管病,其临床常表现为胸闷、胸痛、心悸、叹气、头晕、头痛、晕厥等症状,在体位改变、情绪紧张时加重,卧位后减轻,具有发病率高、容易忽视、反复发作、诊断困难、预后较好的特点。

晕厥患者50例直立倾斜试验阳性高峰时段的确定与护理

晕厥是因各种原因导致一过性脑供血不足引起的意识障碍,其中有相当一部分患者经过各种检查和询问病史仍不能明确病因,称不明原因晕厥（unexplained syncope,US）-（[1]）。直立倾斜试验（head-up tilt table test,HUTT）是利用体位的迅速改变,引起神经体液的过度反应,

儿童晕厥的常见病因及临床研究进展

晕厥（syncope）是指一过性全脑低灌注引起的短暂性意识丧失（T-LOC）,常伴有肌张力丧失而导致姿势不能维持。它是儿童和青少年期常见疾病,引起的病因复杂,其中自主神经介导性晕厥（AMS）是最常见的病因,而血管迷走性晕厥（VVS）是反射性晕厥中最常见的类型,临床上直立倾斜实验是其重要的诊断方法之一。

排便性晕厥的研究进展

晕厥是指突发且短暂的全脑组织缺血缺氧导致的可逆性意识丧失,其特点为发作迅速、短暂,发作时不能保持正常身体姿势[1-3]。排便性晕厥（defecation syncope,DS）是排便中,排便刚结束,腹部绞痛或有便意但未排便时自主神经功能紊乱引起的心率、血压骤降,导致脑灌注不足出现的短暂意识丧失。DS是神经介导性晕厥（反射性晕厥）的一种[1],

Management and therapy of vasovagal syncope: A review

Vasovagal syncope is a common cause of recurrent syncope. Clinically, these episodes may present as an isolated event with an identifiable trigger, or manifest as a cluster of recurrent episodes warranting intensive evaluation. The mechanism of vasovagal syncope is incompletely understood. Diagnostic tools such as implantable loop recorders may facilitate the identification of patients with arrhythmia mimicking benign vasovagal syncope. This review focuses on the management of vasovagal syncope and discusses the non-pharmacological and pharmacological treatment options, especially the use of midodrine and selective serotonin reuptake inhibitors. The role of cardiac pacing may be meaningful for a subgroup of patients who manifest severe bradycardia or asystole but this still remains controversial.

Deceleration Capacity--A Novel Measure for Autonomic Nervous System in Patients with Vasovagal Syncope on Tilt-table Testing

This study was to investigate the changes of autonomic nerve function and hemodynamics in patients with vasovagal syncope(VVS) during head-up tilt-table testing(HUT). HUT was performed in 68 patients with unexplained syncope and 18 healthy subjects served as control group. According to whether bradycardia, hypotension or both took place during the onset of syncope, the patients were divided during the test into three subgroups: vasodepressor syncope(VD), cardioinhibitory syncope(CI) and mixed syncope(MX) subgroups. Heart rate, blood pressure, heart rate variability(HRV), and deceleration capacity(DC) were continuously analyzed during HUT. For all the subjects with positive responses, the normalized low frequency(LFn) and the LF/HF ratio markedly decreased whereas normalized high frequency(HFn) increased when syncope occurred. Syncopal period also caused more significant increase in the power of the DC in positive groups. These changes were more exaggerated compared to controls. All the patients were indicative of a sympathetic surge in the presence of withdrawal vagal activity before syncope and a sympathetic inhibition with a vagal predominance at the syncopal stage by the frequency-domain analysis of HRV. With the measurements of DC, a decreased vagal tone before syncope stage and a vagal activation at the syncopal stage were observed. The vagal tone was higher in subjects showing cardioinhibitory responses at the syncopal stage. DC may provide an alternative method to understand the autonomic profile of VVS patients.

Diagnosis and management of postural orthostatic tachycardia syndrome：A brief review

Postural orthostatic tachycardia syndrome （POTS） has been recognized since at least 1940.A review of the literature identifies differences in the definition for this condition and wide variations in treatment and outcomes.This syndrome appears to describe a group of conditions with differing pathophysiology,which requires treatment tailored to the true underlying disorder.Patients need to be fully evaluated to guide treatment.Further research is required to effectively classify the range of underlying pathophysioiogy that can produce this syndrome and to guide optimal management.

Arrhythmogenic epilepsy and pacing need: A matter of controversy

There is increasing awareness among the cardiology community regarding ictal bradyarrhythmias as a cause of loss of consciousness. A high degree of suspicion is necessary when diagnosing ictal bradyarrhythmias, and delay in diagnosing this condition may lead to morbidity associated with falls and trauma. Ictal bradyarrhythmias have also been suggested to be associated with sudden unexplained death in epilepsy, although evidence related to this association is limited. There is no guidelinedirected therapy for symptomatic ictal bradyarrhythmias due to a lack of randomized, controlled trials. Cardiac pacemaker therapy is commonly used for these patients; however, currently, there is no universal agreement on the pacing indications for these patients. In this review, we focus on the pathophysiology and clinical presentation of ictal bradyarrhythmias and then discuss the pacing need based on the available literature data.

Serious response during tilt-table test in elderly and its prophylactic management

Objective: To evaluate the serious response during tilt-table test (TTT) and its prophylactic management. Method: Seventy-six elderly patients were tested at a tilt angle of 70 degrees for a maximum of 45 min and then subjected to isoprotere- nol-provocative tilt testing. ECG and blood pressure were monitored during the test and patients were kept at normal saline con- dition through a peripheral intravenous duct. Results: Fifty-one of 76 patients were defined as positive including 23 having serious response; 6 of the 23 patients had arteriosclerosis involving internal carotid arteries and 7 cases had bradycardia, two of which were associated with II°-I A-V block and the others with chronic atrial fibrillation. The serious response consisted of cardiac arrest for more than 5 s (6 cases), or serious bradycardia for more than 1 min (7 cases) or serious hypotension for more than 1 min (10 cases). Those with serious response were managed by returning to supine position, thus driving up legs and intravenous atropine, CPR (2 cases with cardiac arrest) and needing oxygen supplementation (11 cases). Only 2 hypotension patients recovered gradually by 10 min after emergency management, while others recovered rapidly with no complications. Conclusion: Although non-invasive, TTT may result in serious response, especially in elderly. Therefore proper patient selection, control of isoproterenol infusion and close observation of vital signs are decisive for a safe consequence.

不明原因的晕厥与植物神经系统功能的关系

晕厥(syncope)是一组急而短暂的意识丧失征候群,临床上根据不同原因可把晕厥分为心血管性、非心血管性和不明原因三大类。本文对25例临床已排除器质性病因的不明原因晕厥病人进行植物神经系统功能检测,发现不明原因的晕厥与植物神经系统功能失调有关,现报告如下。一、对象晕厥组(sc)25例,其中男15例,女10例,年龄18～61岁,平均40.6±12.3岁。发作诱因多与变动体位、排尿或过度劳累等有关.持续时间多为5分钟左右,发作频率为每年1～2次。

Syncope as a health risk for soldiers: Influence of medical history and clinical findings on the sensitivity of head-up tilt table testing

Background: Syncope is a relevant health problem in military environments. Reliable diagnosis is challenging. Tilt table testing is an important tool for syncope diagnosis. The aim of this study was to determine whether signs such as prodromal symptoms, co-morbidity, frequency of syncopal events, body length, body mass index, and electrocardiography(ECG) abnormalities can be used to predict the success of tilt table testing at diagnosing syncope.Methods: Data from 100 patients with histories of syncope or pre-syncope, who were diagnosed using head-up tilt table testing, were retrospectively analyzed in a cross-sectional analysis. The diagnostic procedure was based upon a modified version of the Westminster protocol without any pharmacological provocation. Results: Patients showing pathological reaction patterns during tilt table testing suffered from prodromal symptoms, such as dizziness and sweating, significantly more often. The patients reported more injuries resulting from syncopal events and more previous syncopal events, and the prevalence of co-morbidity was greater among patients presenting negative findings during tilt testing. An asthenic-leptosomal physique was not confirmed as a risk factor for syncopal events as is the case for idiopathic arterial hypotension. However, patients with pathological reaction patterns during tilt table testing were significantly taller. This finding was detected for both females and males. No significant predictors were found in the ECG patterns of patients showing syncope during tilt table testing.Conclusions: Frequency of prior syncope and prodromal symptoms, and increased body length with an otherwise good state of health influence the predictive value of tilt table testing for syncope diagnosis. In particular, if these factors are present, tilt table testing should be considered part of the diagnostic algorithm for soldiers with recurrent syncope.