小儿血管迷走性晕厥的诊治进展

血管迷走性晕厥(VVS)是小儿不明原因晕厥中最常见的原因,倾斜试验是诊断VVS的基础方法,舌下含服硝酸甘油斜板试验和异丙肾上腺素激发试验可进一步提高VVS诊断的敏感性,饮水试验可使倾斜试验阳转阴.目前VVS的治疗以非药物治疗--健康教育和自身调整为主,饮水试验是一种简单有效可行的防治措施,药物治疗尚需多中心合作的进一步研究,对倾斜试验中VVS患儿的心率、血压变化的监测,可能对药物治疗疗效有预测作用.     

直立倾斜试验对不明原因晕厥患儿的诊断价值

目的：讨基础直立倾斜试验对不明原因晕厥(UPS)患儿的诊断价值。方法：UPS患儿30例,年龄6～18岁,平均(11.74±2.82)岁,采用电动倾斜床取头高脚低位直立倾斜70° 后每 5 min自动测量血压和心电变化,评价倾斜试验结果。结果：30例UPS中倾斜试验阳性10例(占 33.3%),反应类型为心脏抑制型及血管抑制型各5例,晕厥发作在倾斜站立10～40 min,平均(24.0±12.2) min。结论：倾斜试验是诊断儿童血管迷走性晕厥(VVS)的有效方法,对临床UPS患儿具有很好地诊断价值。     

直立倾斜试验在儿童血管迷走性晕厥中的诊断价值

目的：探讨直立倾斜试验儿童血管迷走性晕厥的诊断价值。方法：对24例不明原因晕厥的患儿进行基础直立倾斜试验，并以12名正常儿童作对照，在倾斜过程中动态观察心电图、血压、心率，并进行分析。结果：24例晕厥患儿中，基础直立倾斜试验阳性16例，而对照组为0.诊断敏感度为67%,特异度为100%,诊断价值为78%.16例阳性反应中，心脏抑制型反应3例（19%），表现为心动过缓，血压无变化；血管抑制型反应9例（56%），表现为血压下降，心率加快；混合型反应4例（25%），表现为心率、血压均有明显下降。结论：基础直立倾斜试验可作为儿童血管迷走性晕厥的一种重要诊断方法。     

不明原因晕厥患儿直立倾斜试验中血流动力学反应模式及意义

目的　探讨不明原因晕厥患儿在直立倾斜试验中血流动力学反应模式及构成比例。方法　对 2 0 0 1年1月至 2 0 0 3年 12月北京大学第一医院儿科收治的 90例不明原因晕厥患儿在安静环境下进行直立倾斜试验或硝酸甘油激发的直立倾斜试验 ,持续监测患儿心率和血压变化。结果　 90例不明原因晕厥患儿直立倾斜试验中 ,经典的血管迷走性反应者 4 9例 ( 5 4 4 % ) ,其中血管抑制型 33例 ( 36 7% ) ,心脏抑制型 6例 ( 6 7% ) ,混合型 10例( 11 1% )。正常直立反应者 12例 ( 13 3% ) ,体位性心动过速反应者 2 8例 ( 31 1% ) ,直立性低血压反应者 1例( 1 1% ) ,没有发现自主神经反应障碍型及心脏变时功能障碍型。结论　不明原因晕厥患儿在直立倾斜试验中以经典的血管迷走性反应为主 ,其次为体位性心动过速综合征的反应 ,还可能出现体位性低血压等其他的异常血流动力学变化     

儿童血管迷走性晕厥的临床特征及血浆和血小板中5-羟色胺的变化

目的 探讨小儿血管迷走性晕厥的临床特征和血浆、血小板中5-羟色胺(5-HT)的变化.方法 2006年10月-2009年2月在首都儿科研究所经直立倾斜试验(head-up tilt test,HUTT)确诊为血管迷走性晕厥(VVS)患儿41例(HUTT阳性组),诊断标准参照基础HUTT对儿童不明原因晕厥的诊断研究,男17名,女24名,年龄6～14岁,平均年龄(10.5 ±1.8)岁.匹配健康儿童(对照组):当地幼儿园和中小学36名健康小儿,男16名,女20名,年龄9～14岁,平均年龄(10.7±1.5)岁.分析晕厥诱因和先兆症状、HUTT反应方式、晕厥发作时间、VVS患儿静息状态各亚型血压和心率变化等临床特点.全体研究对象抽取静脉血3 ml,用双抗体夹心酶标免疫分析(ELISA)法对41例血管迷走性晕厥患儿及36名健康儿童的血浆和血小板中5-HT进行测定.结果 ①41例血管迷走性患儿平均年龄为(10.5±1.8)岁,女童比例高于男童,为1.4:1.②VVS先兆症状:患儿中33例存在晕厥先兆(80.4%),其中头晕发生率高达78.8%.③VVS发生诱因:儿童VVS发作前常存在诱发因素,包括:长久站立、劳累、情绪影响等.其中长久站立比例最高,达90.2%.④HUTT平均反应时间及晕厥持续时间:基础直立倾斜试验(BHUT)阶段平均反应时间为(20.6±8.6)min;舌下含化硝酸甘油激发倾斜试验(SNHUT)阶段平均反应时间(5.0±2.2)min.晕厥持续时间均短于5 min.⑤HUTT不间反应类型的分布:血管抑制型61.0%,混合型24.4%,心脏抑制型14.6%.⑥血压和心率的比较:VVS患儿和正常儿童静息状态下基础心率、收缩压、舒张压相比差异无统计学意义;VVS患儿中血管抑制型、混合型和心脏抑制型静息状态下基础心率、收缩压、舒张压相比差异无统计学意义.⑦VVS患儿基础状态和HUTT阳性时血浆中5-HT较对照组差异无统计学意义[(27.51±1.32)μg/Lvs.(27.28±2.48)μg/L,t=0.518,P=0.606;(27.51±1.32)μg/L vs.(28.05 ±1.40)μg/L,t=2.044,P=0.167],基础状态下血小板5-HT与对照组之间差异无统计学意义[(82.30 ±6.06)10~9ng/L vs.(79.88±5.79)10~9ng/L,t=1.788,P=0.780].⑧VVS患儿基础状态下和HUTT阳性时的血小板5-HT比较差异有统计学意义[(82.30±6.06)10~9ns/L vs.(97.90±6.59)10~9ng/L,t=11.26,P=0.00].结论 VVS患儿具有明显的临床特征;VVS患儿基础状态和晕厥(或晕厥先兆发生时)血浆中5-HT变化不明显;VVS患儿晕厥或晕厥先兆发生时血小板5-HT明显升高,提示中枢5-HT系统可能参与了VVS的发病过程.     

β_1肾上腺素受体基因多态性与小儿血管迷走性晕厥的相关性研究

目的探讨β1肾上腺素受体(ADRB1)基因多态性Arg389Gly与小儿血管迷走性晕厥(VVS)发病的相关性。方法晕厥组为不明原因晕厥(unexplained syncope,UPS)患儿54例,其中男18例,女36例,平均11.8岁;对照组为同期健康体检儿童54例,其中男20例,女34例,平均11.2岁。入选病例均行直立倾斜试验(head-up tilt test,HUTT),根据HUTT结果,分HUTT阳性组即VVS组和HUTT阴性组,各组病例均应用聚合酶链反应PCR和基因测序方法检测ADRB1基因Arg389Gly多态性。结果健康儿童的等位基因Arg389和Gly389的频率分别为73.15%和26.85%,HUTT阳性患儿等位基因Arg389和Gly389的频率分别为66.67%和33.33%,HUTT阴性患儿等位基因Arg389和Gly389的频率分别为85.42%和14.58%;HUTT阳性患儿的Gly389等位基因频率明显高于HUTT阴性组患儿及健康对照儿(P<0.05)。HUTT阳性组共30例(55.6%),其临床分型中心脏抑制型6例(20.0%),混合型9例(30.0%),血管抑制型15例(...     

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目的探讨米多君对血管迷走性晕厥儿童的治疗效果。方法将2003-07—2004-12在北京大学第一医院儿科就诊的46例晕厥反复发作、直立倾斜试验(HUT)阳性的血管迷走性晕厥患儿,分为米多君组、美托洛尔组及基础治疗组。首先应用HUT评价患儿的治疗反应及调整药物,所有患儿随访6个月后,如没有晕厥的发作者则停药,并继续随访。进一步评价患儿晕厥复发情况及药物的不良反应。结果米多君组、美托洛尔组及基础治疗组3组患儿HUT转阴率分别为75·0%、65·0%及20·0%。米多君组及美托洛尔组患儿的HUT转阴率明显高于基础治疗组(P均<0·05),而给药治疗的两组患儿的HUT转阴率差异无显著性(P>0·05)。在随访过程中,米多君组及美托洛尔组晕厥复发率分别为22·2%及30·7%,而基础治疗组的晕厥复发率为80·0%,前两组晕厥复发率显著低于后组(P均<0·05)。前两组之间的复发率差异无显著性(P>0·05)。结论米多君可有效治疗血管迷走性晕厥儿童。     

基础直立倾斜试验对儿童不明原因晕厥的诊断研究

为探讨基础直立倾斜试验对不明原因的晕厥患儿的诊断价值，应用直立倾斜试验（倾斜角度６０度，试验持续时间４５分钟）对４２例不明原因的晕厥患儿进行诊断研究，并以１３名正常小儿作对照。结果：基础直立倾斜试验在不明原因晕厥患儿的阳性率为６７％，对照组阳性率为０。诊断敏感度、特异度及诊断价值分别为６７％、１００％及７４％。阳性反应诱发时间为２２±１２分钟。在２８例阳性反应患儿中，１５例为血管抑制型反应，表现为血压明显下降，心率增快；３例为心脏抑制型反应，表现为心率明显下降，血压不变；１０例为混合型反应，其血压、心率均明显下降。提示：基础直立倾斜试验可较好地、客观地对血管迷走性晕厥进行诊断。     

儿童血管迷走性晕厥直立倾斜试验中心电图的变化

目的 探讨儿童血管迷走性晕厥(VVS)直立倾斜试验(HUTT)中ECG的变化.方法 选取本院门诊及住院晕厥患儿123例,经详细询问患儿病史,行体格检查、常规12导联ECG及头颅CT等一系列检查,疑诊VVS 65例.疑诊VVS患儿停用可能影响自主神经功能的饮食,停用血管活性药物5个半寿期以上(6～8 d),行HUTT或舌下含化硝酸甘油倾斜试验.结果 VVS患儿HUTT中可出现各种心律失常,以窦性心动过速多见[40例(61.5%)],结性逸搏心律次之[23例(35.4%)].HUTT阳性类型:血管抑制型45例(69.2%),混合型16例(24.6%),心脏抑制型41例(6.2%).结论 VVS儿童HUTT中可出现各种心律失常.VVS患儿应严密观察ECG变化,必要时积极干预,以免发生意外.     

神经系统及精神疾病

05 1 72 2　直立倾斜试验对儿童血管迷走性晕厥的诊断价值 /王慧远…∥临床儿科杂志 .-2 0 0 4,2 2 (6) .-3 91临床资料 :晕厥组 :不明原因晕厥患儿 45例 ,对照组 :无晕厥病史正常儿童 2 0例。 2组病例体检、心电图、超声心动图、脑电图、脑 CT及血糖均正常。晕厥组和对照组小儿间性别、年龄、基础血压及基础心率差异均无显著性(P>0 .0 5 ) ,晕厥次数在直立倾斜试验阳性及阴性反应小儿中 ,差异也无显著性。结果 :直立倾斜试验阳性率晕厥组阳性率 64.4% (2 9/45例 ) ,对照组阳性率 5 .0 % (1 /2 0例 ) ,2组阳性率差异非常显著 (P<0 .0 0 1 …     

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??Objective??To evaluate the chronotropic competence in children with vasovagal syncope ??VVS??. Methods??Thirty-nine patients??17 males??22 females??age ranging from 8-16 years?? with syncope were included in the study??and 28 were diagnosed with VVS??including 15 cases of vasodepressor type??9 cases of mixed type??and 4 cases of cardioinhibitory type??11 were with unexplained cause of syncope. A treadmill test was performed and heart-rate response during exercise was evaluated by the chronotropic reserve. Demographic data and change of heart rate??blood pressure during test and CRI were compared between the 2 groups and different types of VVS. Furthermore??based on CRI??patients with VVS were divided into the normal chrontropic group??n??10?? and CI group??n??17??. By following the recurrence of syncope of 2 groups??the effect of CI on the prognosis of VVS in children was observed. Results??There were no significant differences between children with VVS and with unexplained syncope in sex??age??BMI??baseline heart rate??MaxMET or baseline blood pressure. But during exercise test??peak heart rate and CRI were significantly lower in children with VVS than in unexplained syncope. The incidence of CI in children with VVS was significantly higher than that in children with unexplained syncope??64.3% vs. 27.3%??P??0.05??. The incidence of CI in VVS with vasodepressor-type in children was significantly lower than those with cardioinhibitory-type and mixed-type. During following-up period??the recurrence rate of syncope in VVS children with CI was significantly higher than that of children without CI. Patients with CI had significantly worse prognosis compared to those without CI??Log-rank??P??0.028??. Conclusion??Chrontropic competence is significantly altered in children with VVS??especially in cardioinhibitory-type and mixed-type in children. CI is the significant predictor for poor prognosis in children with VVS.     

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目的探讨直立倾斜试验(HUTT)对儿童血管迷走性晕厥(VVS)反复发作的预测价值。方法2001-01—2006-08在中南大学湘雅二医院晕厥专科门诊就诊或住院的不明原因晕厥患儿251例,男112例,女139例,年龄418(12.25±3.27)岁。依临床晕厥发生频次分A组(晕厥发作仅1次,n=54)、B组(晕厥发作24次,n=137)与C组(晕厥发作≥5次,n=60)。HUTT在取得知情同意后采用基础直立倾斜试验(BHUT,n=251)及舌下含服硝酸甘油倾斜试验(SNHUT,n=92)。结果(1)HUTT阳性率与晕厥频次关系:BHUT阳性率随晕厥频次增加而递增(χ2=4.285,P>0.05),SNHUT阳性率与晕厥频次不呈线性关系(χ2=1.316,P>0.05),HUTT总阳性率(指BHUT阳性率+SNHUT阳性率)亦随晕厥频次增加而递增(χ2=3.809,P>0.05)。(2)HUTT反应类型与晕厥频次关系:无论是BHUT还是SNHUT,反应类型以血管抑制型为主,BHUT或SNHUT在不同晕厥频次组间比较无明显差异(分别为χ2=3.008,P>0.05;χ2=2.426,P>0.05)。结论HUTT与儿童VVS临床晕厥反复发作频次无明显关系,对儿童VVS临床反复晕厥发作没有预测价值。     

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目的应用多普勒超声显像法探讨血管迷走性晕厥(VVS)儿童的血管内皮功能。方法研究对象共20例,均为2002年1月至2003年12月在北京大学第一医院儿科就诊儿童,分为VVS组(n=10)及非VVS对照组(n=10),对10例经直立倾斜试验确诊的血管迷走性晕厥儿童,应用多普勒超声测定肱动脉的血流介导的血管舒张反应,并与10例经直立倾斜试验除外VVS的对照组儿童进行比较。结果两组患儿的年龄、性别、身高、体重、基础血压及基础肱动脉血管内径均无显著性差异,但血管迷走性晕厥儿童的血管内皮依赖性舒张功能较对照组显著增强[(11.93±4.46)%vs(8.46±2.18)%,P<0.05]。结论血管内皮依赖性舒张功能增强可能是儿童血管迷走性晕厥发生机制之一。     

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目的探讨舌下含服硝酸甘油倾斜试验(SNHUT)对儿童血管迷走性晕厥(VVS)的诊断价值。方法2001年3月至2005年5月在中南大学湘雅二医院儿童晕厥专科就诊或住院的不明原因晕厥(UPS)患儿143例,年龄4～18(12.10±3.03)岁,男58例,女85例。电动倾斜床直立倾斜70°行基础直立倾斜试验(BHUT),并对其阴性者中的64例在同一角度直接给予舌下含服硝酸甘油片0.2mg,再次评价试验结果。用SPSS11.0软件进行微机统计学处理。结果(1)BHUT阳性率29.4%(42/143),其中女性占73.8%(31/42);SNHUT64例,阳性44例,阳性率为68.7%。SNHUT显著地提高了VVS的检出率。(2)出现阳性结果的时间BHUT为(21.31±13.24)min,SNHUT为(5.41±4.23)min。(3)反应类型BHUT及SNHUT阳性患儿共86例,血管抑制型83.7%(72/86),女性占53.5%(46/86);心脏抑制型7.0%(6/86),均为女性;混合型9.3%(8/86),女性占62.5%(5/8)。(4)副反应舌下含服硝酸甘油64例,未见明显不耐受现象或其他副反应。结论SNHUT能提高儿童VVS诊断阳性率,副反应小,使用方便,可在儿科临床推广。     

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??Objective To analyze the cerebral blood flow dynamics of vasovagal syncope??VVS?? by transcranial cerebral Doppler??TCD?? and explore the clinical value of TCD to VVS. Methods A total of 38 children with vasovagal syncope and 20 healthy children received head-up tilt test??HUTT??. In the process of test??they were monitored by TCD. Results Under basic condition??there were no obvious differences between patients and healthy children on the result of TCD. In the process of HUTT for healthy children??there were no obvious differences on the result of TCD. In the process of HUTT for vasovagal syncope children??compared with data of TCD under basic condition??the cerebral blood flow velocity??Vs??Vd??Vm?? and pulse index??PI?? had great improvement when syncope was induced by HUTT. Conclusion Patients with vasovagal syncope have obstacles in terms of cerebral blood flow regulation. TCD can become a routine examination method in those children with vasovagal syncope.     

舌下含化硝酸甘油直立倾斜试验对儿童不明原因晕厥的诊断研究

目的 探讨舌下含化硝酸甘油直立倾斜试验对不明原因晕厥患儿的诊断价值。方法 对25例不明原因晕厥的患儿(晕厥组)及10例无晕厥史的正常健康儿童(对照组)先行基础直立倾斜试验,阴性者再行舌下含化硝酸甘油直立倾斜试验(4～6μg／kg,最大量不超过300μg)。结果 基础直立倾斜试验在晕厥组的阳性率为48％(12／25),对照组为0;舌下含化硝酸甘油直立倾斜试验在晕厥组阳性率为80％(20／25),对照组为20％(2／10);舌下含化硝酸甘油直立倾斜试验诊断的敏感度、特异度及诊断价值均为80％。两组患儿中仅有1例在试验中出现头痛,但能坚持试验完成。结论 舌下含化硝酸甘油直立倾斜试验对诊断儿童血管迷走性晕厥具有良好的敏感性和特异性,且具有操作简便、不良反应小的特点。值得推广应用。     

Sublingual Isosorbide Dinitrate-Stimulated Tilt Test for Diagnosis of Vasovagal Syncope in Children and Adolescents

Vasovagal syncope is the most likely cause of syncope in the young. Head-up tilt-table test (HUT) provides the ability to provoke vasovagal syncope under controlled laboratory settings. In adult populations, pharmacologic stimulation with intravenous/sublingual isosorbide dinitrate (ISDN) has been shown to be an alternative to isoproterenol for increasing the diagnostic yield of HUT. In this study, 40 patients aged 9-18 years with unexplained syncope and 12 healthy age-matched children were evaluated by HUT to 70 degrees for 45 minutes. If tilting alone did not induce symptoms (syncope and presyncope), 0.1 mg/kg ISDN was given while the patient lay supine. After 5 min, the table was tilted to 70 degrees for 15 min or until the symptoms occurred. The control group consisted of 12 healthy age-matched children studied in a similar manner. Six patients (15%) had a positive basal tilt test. Twenty-five patients (62.5%) lost consciousness following ISDN administration. In the control group, nobody had a syncopal episode during the basal tilt test. However, ISDN administration resulted in 1 positive response (8.3%). The sensitivity of the test was 77.5% and its specificity was 91.6%. It is concluded that sublingual nitroglycerin HUT is suitable for routine clinical practice in children and adolescents with unexplained syncope.     

Association of Clinical Characteristics of Unexplained Syncope with the Outcome of Head-Up Tilt Tests in Children

The aim of this study was to clarify the association of clinical characteristics of unexplained syncope with the outcome of the head-up tilt test (HUT) in children. A total of 47 patients with unexplained syncope were classified into two groups according to their outcomes of HUT: the positive response group and the negative response group. We reviewed their clinical data as well as the results of HUT and analyzed them with logistic regression method. The results showed that the incidence of positive responses to HUT was higher in girls than in boys (8/22 vs 10/7, p < 0.05). Compared with fainted children younger than 12 years of age, 12- to 16-year-old adolescents with unexplained syncope had a high positive outcome of HUT (30 vs 72.9%, p < 0.05). Compared with fainted children with negative response of HUT, children with positive response to HUT often had syncope in special circumstances (e.g., prolonged standing, anxiety and fright, and morning exercise), and they often had prodrome, such as pallor, lightheadedness, and nausea (28/30 vs 8/17, p < 0.05). However, the number and duration of syncopal spells did not relate to the positive responses to HUT. The logistic regression analysis showed that three factors significantly influenced the outcome of HUT: predisposing factors of syncope, prodrome of syncope, and age (p < 0.05; OR = 32.9434, 17.7281, and 2.7842, respectively). Hence, if pubertal girls with unexplained syncope had clear predisposing factors and prodromes, they were likely to have positive responses to HUT, and they were likely to be clinically considered as having vasovagal syncope.     

The value of the head-up tilt table test for with unexplained syncope in children and young adolescents

Syncope occurs in about 15% of children and young adolescents. The diagnosis of syncope of unknown origin is frequently difficult. In 1986, Kenny et al. introduced the Head-up Tilt Table Test (HUT), which enables to reproduce syncope. The aim of the study was to evaluate HUT in diagnosis of syncope in children and young adolescents. Ninety five children and young adolescents (57 females, 38 males, age range 7-18 years) with recurrent syncope of unexplained etiology were referred for HUT. The study group was divided into two subgroups: A--with history consistent with vasovagal syncope (VVS) and B--with non-characteristic symptoms for VVS. HUT was performed according to the Westminster protocol. The patient was tilted at 60 degree for 45 min. or until syncope occurred. Positive response to HUT was 36%. Negative outcome occurred in 59%. Non-diagnostic HUT was observed in 5%. The vasodepressive type of VVS was recognised in 35%, cardioinhibitory in 12% and mixed in 53%. In group A positive response of HUT occurred in 65% of pts., negative in 31%. In group B positive HUT was observed in 4% of pts. and negative in 89%. CONCLUSIONS: 1. In children and young adolescents head-up tilt test is a very useful diagnostic method. 2. In patients referred for the head-up tilt test the history of syncope should be taken into consideration.