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.

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.

Evaluation of cilazapril in vasovagal syncope treatment

Objective: to evaluate cilazapril in vasovagal syncope treatment. Method: eighty\|six cases of VVS patients found positive in TTT tilt were medicated with 2.5 mg cilazapril daily for three months and followed up by TTT. Results: seven cases quit due to cough or unexplained reason; 79 VVS patients had no more fainting spells; 75.95% of TTT results of patients changed to negative after 3 months therapy. The before and after cilazapril treatment average blood pressures (taken in lying position) were 121/73 mm Hg (1 mm Hg= 0.133kPa) and 120/76 mm Hg respectively ( P > 0.05); and mean heart rates were 68.63±12.37/min and 70.13±13.15/min respectively with no significant changes ( P > 0.05). Conclusion: Cilazapril was effective in treatment of VVS; did not affect normal blood pressure and heart rate; was safe; and had little side effect.

Different treatments for different mechanisms in vasovagal syncope

The treatment of vasovagal syncope has been by far unsatisfactory. Beta-blockers may prevent vasovagal syncope, but they exacerbates heart asystole. Cardiac pacing prevents syncope but notpresyncope. The frequent, serious vasovagal syncope attacks of a 63- year-old woman patient were completely prevented by administration of 100 mg metoprolol (b.i.d) for 3 months until the patient experienced a complete heart block. A DDD pacemaker implantation abolished syncope but not the presyncope, which was eventually prevented in a follow-up period of 24 months by adding 75 mg atenalol twice a day. This case suggests a different mechanism involved in vasovagal syncope.

Myoclonus and Recurrent Cardioinhibitory Vasovagal Syncope after Abdominal Surgery in a Critical Care Setting

Letter to the

Minimal Vasovagal Dysautonomia in Patients with Rare or Unique Syncope

Introduction: It is common to find people sent to perform a Head Up Tilt Test (HUT) who suffered a single syncope, or syncopes that occur during certain periods and never appear again. We wonder how these people are different from those who have never had syncope. Methods: We found 300 patients who suffered only one (unique) or a maximum of 5 vasovagal syncopes during their life. And their HUT was positive for vasovagal dysautonomia. We compared them, with 120 healthy volunteers who have never had syncope. We try to explain how some constitutional predisposing factors act in these patients, and are associated with environmental triggers to precipitate the syncope. Results: We found differences between cases and controls in predisposing factors such as: heredity, joint hypermobility, baroreflex failure, venous compliance and some neurological diseases. Then an environmental factor acts as a trigger for syncope: prolonged standing, stress, pain and emotions, dehydration, use of certain drugs, abundant food. Conclusions: There are people with minimally expressed vasovagal dysautonomia who have an organic predisposition to present vasovagal syncopes (heredity, joint hypermobility, baroreflex failure, venous compliance, some neurological diseases, etc.). But this predisposition is not enough by itself to produce syncopes. One or more environmental factors must be added, acting as a trigger that would be the reason why these episodes are so infrequent.

Predictive Value of Blood Pressure,Heart Rate,and Blood Pressure/Heart Rate Ratio in a Chinese Subpopulation with Vasovagal Syncope

Objective:The head-up tilt test(HUTT)is widely used but is time-consuming and not cost-effective to evaluate patients with vasovagal syncope(VVS).The present study aims to verify the hypothesis that ambulatory blood pressure(BP)monitoring(ABPM)and the simplistic tilt test may be potential alternatives to the HUTT.Methods:The study consecutively enrolled 360 patients who underwent the HUTT to evaluate VVS.BP),heart rate(HR),and BP/HR ratios derived from ABPM and the simplistic tilt test were evaluated to predict the presence,pattern,and stage of syncope during the HUTT.Results:Mixed response was the commonest pattern,and syncope occurred frequently with infusion of isoproterenol at a rate of 3μg/min.During the simplistic tilt test,the cardioinhibitory group had higher tilted BP/HR ratios than the vasodepressor group,while the vasodepressor group had a faster tilted HR and a larger HR difference than the cardioinhibitory group.The higher the BP/HR ratio in the tilted position,the higher the isoproterenol dosage needed to induce a positive response.During ABPM,BP/HR ratios were signifi cantly higher in the cardioinhibitory group than in the vasodepressor group.The higher the ABPM-derived BP,the higher the dosage of isoproterenol needed to induce syncope.There were signifi cant correlations in BP/HR ratios between ABPM and the supine position in the vasodepressor group,while signifi cant correlation was found only for the diastolic BP/HR ratio between ABPM and the tilted position in the cardioinhibitory group.The mixed pattern shared correlative features of the other two patterns.Conclusion:ABPM and the simplistic tilt test might be used as promising alternatives to the HUTT in VVS evaluation in clinical settings.

Cause analysis of vasovagal syncope induced by treadmill exercises test

AIM:To evaluate the treadmill exercise t est on vasovagal syncope and the avoidance steps.METHOD:Examination of treadmill exercise t est of 64adults and analyse of the history,pr etest heart rate,the maximum heart r ate,metabolic equivalent (MET)and tilt table test.RESULTS:Exercise tolerances in both groups were same with signifi cantly increase of syncope history(43/64,67%in syncope group,while 11/64or 9%in the controls)and lower basic heart rate of the subjects(74±11in the syncope group;66±10in t he con-trols,with P<0.01statistically)in the syncope group.HUTT positive s ub-jects were significantly more in the syncope group(48/64,75%)than in the controls(2/64),with P<0.01statistically.CONCLUSION:The exercise syncope was based on the pretest heart rate and previous syncopal history rather than the exercise tolerance in healt h adults.It suggested an underlying abnor-mality which may predispose to exerc ise subjects with vasovagal syncope.

The Changes of Baroreflex Sensitivity During Head-up Tilt Test and Its Clinical Significance in the Patients with Vasovagal Syncope

Objective To study thechanges of baroreflex sensitivity (BRS) during head - up tilt test (HUT) in patients with vasovagal syncope (VS), and to examine the relationship between baroreflex sensitivity and neurohormonal factors. Furthermore, to investigate the effects of the changes of BRS on VS. Methods Forty - two patients with unexplained syncope (Among the 42 patients, there were 22 patients with positive HUT and 20 patients with negative HUT respectively) and 20 healthy volunteers (with negative HUT) underwent passive head - up tilt testing, Ante-cubital vein blood samples were taken before and after HUT, or at syncope. The fasting plasma endothelin , serum nitric oxide (NO), serum NE were measured, the BRS was assessed on the basis of the linear regression slope the RR interval versus systolic arterial blood pressure during the increment in blood pressure after intravenous administration of phenylephrine. Results (1) During the syncope, the BRS significantly reduced in HUT(+) group than baseline. At the end of tilt, the level of plasma ET, serum NO in patients with positive HUT significantly increased compared with baseline or normal controls, and the plasma concentration of NE also had the trend of increase. (2) By multiple regression analysis, a significant negative correlation was found between baroreceptor sensitivity and the plasma ET, NO at the end of HUT in patients with positive HUT, but there was no relationship between BRS and NE. Conclusions During the syncope occure, the BRS in patients with VS decreased significantly compared with normal controls. The abnormal plasma ET, NO concen-tration might contribute to the mechanism of VS.

Syncope Beginning in People Over 50 Years Old—Experience in 52 Cases

It is not common to start suffering from syncopes after age 50. They are mainly male patients who present causes other than vasovagal syncope, which predominates at an early age. Orthostatic hypotension is the predominant causal factor, which is attributed in many cases to advanced age, metabolic, cardiovascular or neurological diseases, to failure of baroreflexes, all of the above may be associated with the use of hypotensive drugs alone or in combination with psychotropic drugs. Furthermore, causes such as carotid sinus syncope, postprandial syncope and situational syncope become more frequent. Therefore, as people age, they present a favorable pathological terrain for the production of syncope. The older you are, the more likely you are to start with syncope. Finding the definitive diagnosis for their syncopes can be difficult, given the multiplicity of interacting factors. Their study is more exhaustive and requires a good anamnesis, knowing the drugs used by the patient, concomitant diseases and careful surveillance to get closer to the diagnosis.

血管迷走性晕厥手术治疗的现状与展望

血管迷走性晕厥作为晕厥中最常见的一种形式,心脏抑制型晕厥患者经随机临床试验证实有效的药物疗法有限,可建议使用永久性起搏器治疗。本文梳理了起搏器治疗血管迷走性晕厥中曲折发展经历并总结了原因,根据指南整理了目前适用于起搏治疗的患者类型以及应用的局限性,心脏神经消融术可能成为血管迷走性晕厥患者的另一种选择,但尚需要大样本随机对照试验证实其安全性、有效性以及适用人群。

血管迷走性晕厥患者心脏自主神经消融围手术期护理方案的构建

目的构建血管迷走性晕厥患者心脏自主神经消融围手术期护理方案。方法系统检索2013年1月至2023年12月Cochrane Library、Pub Med、Web of Science核心合集数据库、CINAHL、EMbase、中国知网、万方数据知识服务平台中有关血管迷走性晕厥护理相关证据。选取2023年9月至10月武汉大学中南医院就诊的血管迷走性晕厥患者及医护人员进行半结构式访谈。基于文献研究和半结构式访谈结果初步构建血管迷走性晕厥患者心脏自主神经消融围手术期护理方案。采用德尔菲法邀请15名专家进行两轮函询以完善并确立最终方案。结果两轮函询问卷有效回收率均为100%,专家权威系数分别为0.910,0.913。第1轮函询中,一、二、三级条目Kendall’s W为0.244~0.537(均P<0.01);第2轮咨询中,一、二、三级条目Kendall’s W为0.391~0.643(均P<0.01),各条目重要性评分均数为3.53~5.00分,变异系数为0.000~0.245。最终确定方案包括5个一级条目,13个二级条目和32个三级条目。结论本研究构建的血管迷走性晕厥患者心脏自主神经消融围手术期护理方案科学、可靠,可为临床护理实践提供参考。

直立倾斜试验操作医师累计工作量对血管迷走性晕厥诊断结果的影响性分析

目的:探讨直立倾斜试验操作医师累计工作量对诊断报告结果的影响。方法:回顾性连续纳入中国医学科学院阜外医院自2016年1月1日至2022年12月31日进行直立倾斜试验检查的操作医师和患者资料。根据从本院开展倾斜试验至研究结束这一阶段医师的累计工作量,将医师分为低累计工作量组(累计50~100例)、中等累计工作量组(累计101~350例)、高累计工作量组(累计1000~4000例;无医师累计工作量在351~999例),以及按医师的的性别、学历、职称分别进行分组,分析不同分组内和不同分组间医师倾斜试验报告诊断率的差异。结果:共纳入22名医师操作的6122例患者,22名医师个体之间的阳性、可疑阳性和阴性报告率差异均具有统计学意义(P均<0.001)。中等累计工作量组平均可疑阳性报告率显著高于低累计工作量组和高累计工作量组(3.21%vs.1.09%vs.1.62%,P=0.001),女性医师可疑阳性报告率高于男性医师(2.25%vs.1.07%,P=0.017),本科学历医师可疑阳性报告率高于研究生学历医师(2.46%vs.1.52%,P=0.013),初级职称医师可疑阳性报告率高于中级和高级职称医师(3.40%vs.1.75%vs.2.53%,P=0.024)。多因素Logistic回归分析显示,不论以阴性还是阳性作参照,中等累计工作量均是可疑阳性报告的影响因素(P均<0.05)。结论:不同操作医师个体之间的倾斜试验诊断报告率存在一定差异,中等累计工作量组操作医师更易出具可疑阳性诊断报告。

血管迷走性晕厥伴焦虑患者经颅多普勒联合直立倾斜试验的特点分析

目的分析经血管迷走性晕厥(vasovagol syncope,VVS)伴焦虑患者经颅多普勒联合直立位倾斜实验的特点。方法选择我院2021年7月至2023年7月诊治的患者90例,根据症状不同分为VVS有焦虑组、VVS无焦虑组、焦虑无VVS组,同期健康体检者为健康对照组,每组各30例。收集一般资料、直立倾斜试验(head-up tilt test,HUTT)血流动力学、经颅多普勒(transcranial doppler,TCD)脑血流进行对比,VVS伴焦虑患者治疗前后TCD与复发之间的关系。结果4组间比较,HUTT直立位相比平卧,VVS伴焦虑组心室率增加最少,TCD血流速度在收缩期和舒张期末下降明显,搏动指数和阻力指数增加最多(P<0.01);VVS伴焦虑组治疗后TCD无改善复发率高(P<0.05)。结论VVS伴焦虑患者有自主神经功能异常存在,治疗后TCD预测再发率有临床价值。

Age and mean platelet volume-based nomogram for predicting the therapeutic efficacy of metoprolol in Chinese pediatric patients with vasovagal syncope

Background Vasovagal syncope(VVS)is the most common type of orthostatic intolerance in children.We investigated whether platelet-related factors related to treatment efficacy in children suffering from VVS treated with metoprolol.Methods Metoprolol-treated VVS patients were recruited.The median duration of therapy was three months.Patients were followed and divided into two groups,treament-effective group and treatment-ineffective group.Logistic and least absolute shrinkage selection operator regressions were used to examine treatment outcome variables.Receiver-operating characteristic(ROC)curves,precision-recall(PR)curves,calibration plots,and decision curve analyses were used to evaluate the nomogram model.Results Among the 72 patients who complete the follow-up,treatment-effective group and treatment-ineffective group included 42(58.3%)and 30(41.7%)cases,respectively.The patients in the treatment-effective group exhibited higher mean platelet volume(MPV)[(11.0±1.0)fl vs.(9.8±1.0)fl,P<0.01]and platelet distribution width[12.7%(12.3%,14.3%)vs.11.3%(10.2%,12.2%),P<0.01]than those in the treatment-ineffective group.The sex ratio was significantly different(P=0.046).A fit model comprising age[odds ratio(OR)=0.766,95%confidence interval(CI)=0.594-0.987]and MPV(OR=5.613,95%CI=2.297-13.711)might predict therapeutic efficacy.The area under the curve of the ROC and PR curves was computed to be 0.85 and 0.9,respectively.The P value of the Hosmer-Lemeshow test was 0.27.The decision curve analysis confirmed that managing children with VVS based on the predictive model led to a net advantage ranging from 0.01 to 0.58.The nomogram is convenient for clinical applications.Conclusion A novel nomogram based on age and MPV can predict the therapeutic benefits of metoprolol in children with VVS.

血管迷走性晕厥的诊断现状

血管迷走性晕厥的诊断主要依靠典型的临床症状,直立倾斜试验是主要的辅助诊断手段,但诊断敏感性和特异度有限。近年来心率减速力是新出现的诊断技术,可能有助于血管迷走性晕厥的诊断,但需要多中心、更大人群的验证。

血管迷走性晕厥的家族遗传特征

目的探讨血管迷走性晕厥(VVS)患者的家族遗传特征。方法对383例行倾斜试验(HUTT)检查的不明原因晕厥(UPS)患者详细询问晕厥家族史,并记录建档。结果①9.4%(36/383)UPS患者存在晕厥家族史,HUTT阳性且有晕厥家族史者占12.0%(23/191)。②UPS患者女性明显多于男性,男性有晕厥病史者其后代(一级亲属)男性晕厥发病几率增加18.6%,女性有晕厥病史者其后代(一级亲属)发生晕厥比率女性>男性。③UPS患者21.7%(83/383)、有晕厥家族史且HUTT阳性患者39.1%(9/23)晕厥发作时存在诱因。④有晕厥家族史且HUTT阳性患者混合型比率高于全体HUTT阳性患者(34.8%vs27.7%)。⑤HUTT阳性患者有无晕厥家族史在性别及年龄组间(<18岁与≥18岁)比较差异无统计学意义(P>0.05)。结论VVS存在遗传倾向,尤其是一级亲属有晕厥史者后代晕厥发生几率明显增高,外界因素可促进晕厥发生。

血管迷走性晕厥儿童心率变异性的年龄和性别差异

目的探讨血管迷走性晕厥(VVS)儿童心率变异性(HRV)的年龄和性别差异。方法2003—01～2007—05在中南大学湘雅二医院晕厥专科诊治的不明原因晕厥(UPS)儿童54例(晕厥组),其中<12岁儿童22例,直立倾斜试验(HUTF)全部为阳性反应。匹配48例健康儿童为对照(对照组)。晕厥组和对照组儿童均行24 h动态心电图(Holter)检查,数据经TLC3000A 12通道动态心电图分析系统自动分析结合人工干预生成HRV时域指标和频域指标。结果①晕厥儿童HRV性别比较:与男性儿童相比,女性儿童各项时域指标和频域指标均偏低,其中时域指标总体标准差(SDNN)、均值标准差(sDANN)和频域指标总功率(TP)、低频功率(LF)、极低频功率(VLF)降低显著(P<0.01或P<0.05)。②健康儿童HRV性别比较:女性儿童时域指标SDNN、差值均方根(rMSSD)、差值>50 ms的百分比(pNN50)和频域指标TP、VLF、LF低于男性儿童,其中差异有统计学意义的是频域指标VLF(P<0.01)和LF(P<0.05)。③晕厥儿童HRV年龄比较:与≥12岁儿童相比,<12岁儿童时域指标SDNN、SDANN、pNN50和频域指标TP、LF稍降低(均P>0.05)。④健康儿童HRV年龄比较:与≥12岁儿童相比,<12岁儿童时域指标rMSSD、pNN50和频域指标LF、高频功率(HF)偏高,其中差异有统计学意义的是HF(P<0.05),其余指标稍偏低(均P>0.05)。结论VVS儿童自主神经功能异常,其自主神经变化规律的年龄和性别差异与健康儿童不同。