倾斜试验诊断儿童血管迷走性晕厥研究进展

晕厥在临床上相当常见 ,据国内外统计 ,人群中最少有2 0 %的人发生过一次晕厥 ,占急诊患者的 3%～ 4 % [1 ] ,其中不明原因的晕厥占 70 % [2 ] 。在儿童的晕厥中血管迷走性晕厥是最常见的。直立倾斜试验是诊断血管迷走性晕厥的一种有效的方法 ,亦可作为评估疗效的手段之一 ,更有助于了解此类晕厥发生的机制。新近直立倾斜试验也被广泛用于研究评价儿童及青少年血管迷走性晕厥的发生与治疗 ,发现该人群中血管迷走性晕厥发生率高达 15 % [3] 。现将近年来倾斜试验诊断儿童血管迷走性晕厥的研究进展 ,综述如下。1　晕厥的定义和临床特点晕厥是…     

倾斜试验配合及护理的体会

血管迷走性晕厥 (ＶＶＳ)是诸多晕厥中既特殊又常见的一种类型 ,过去是在排除其它类型晕厥的基础上诊断的 ,故诊断步骤复杂、费时、费资金。本文通过对血管迷走性晕厥产生的病因或诱因、机制、晕厥特点、伴随症状与体征、协助诊断方法及护理要点的分析 ,从而提高该实验的效率 ,有助于确诊血管迷走性晕厥 (ＶＶＳ)。倾斜试验是确诊血管迷走性晕厥的一项特殊性检查 ,我院新近开展此项新的检查项目 ,做好配合护理是此项检查开展顺利和提高试验效率的关键。1　血管迷走性 (血管抑制性 )晕厥　又称普通晕厥 ,最为常见。多发生于体弱的年青女性 ,…     

小儿血管迷走性晕厥的治疗进展

目前，小儿血管迷走性晕厥（VVS）发病机制尚未完全明确，治疗方法缺乏特异性。治疗目标是预防晕厥发作和晕厥导致的损伤，改善生活质量，降低死亡危险。采取非药物和药物相结合的治疗措施。     

晕厥患儿直立倾斜试验中的护理

晕厥是儿科的常见疾病,系脑供血骤然减少或停止而出现的短暂意识丧失,常伴有肌张力丧失而不能维持一定的体位[1],血管迷走性晕厥是儿童晕厥的最常见的病因[2]。直立倾斜试验（HUT）是诊断和评价药物治疗血管迷走性晕厥疗效优劣的标准,分为基础HUT（BHUT）和药物HUT（SNHUT）[3]。现将我科对51例晕厥患儿HUT中的护理介绍如下,旨在为临床加强试验的安全性提供指导。     

直立倾斜试验对血管迷走性晕厥的诊断应用价值

<正> 晕厥是心血管疾病临床中较常见症状,晕厥的病因诊断是诊疗中的难点。神经介导性晕厥是晕厥类型中的常见类型,在各种形式的神经介导性的晕厥中,血管迷走性晕厥最为常见,多发生于青年人,临床无特殊方法加以证实诊断,或与其它形式的晕厥相鉴别。国外近来已广泛采用直立倾斜试验来诱发血管迷走性晕厥,本文结合我院1999-2002年4年来门诊及住院病例中32例不明原因晕厥进行的倾斜试验进行总结,并就倾斜试验对晕厥的诊断和鉴别诊断的临床应用价值进行探讨。     

晕厥患儿28例病因分析

目的分析晕厥儿童的发病情况及病因。方法回顾性分析近几年在我院儿科以晕厥为主诉就诊的28例患儿的临床资料。结果自主神经介导的反射性晕厥是晕厥患儿最常见的病因占50％，其中最多者为血管迷走性晕厥，占所有晕厥患儿的39．29％。其次为神经源性晕厥，占17．86％，心源性晕厥占10．71％。直立倾斜试验（HUTT）是诊断血管迷走性晕厥常用的方法。结论导致儿童晕厥的病因众多，以血管迷走性晕厥最常见，心源性晕厥最危险，仔细的病史采集和体格检查是诊断晕厥患儿的基础。     

直立倾斜试验的临床应用

晕厥是儿科的常见病症,大约有15% 的儿童有过晕厥的经历.其中,血管迷走性晕厥(vasovagal syncope,VVS)约占所有晕厥的80%[1].自Kenny等首先开创性将直立倾斜试验(head-up tilt test ,HUT)运用于临床诊断血管迷走性晕厥以来,经过各国学者20多年的研究,其方法不断改进和完善,诊断率也明显提高,现已被国内外公认为诊断血管迷走性晕厥的金标准.……     

儿童血管迷走性晕厥的新概念

晕厥是儿童的常见病症,据一项美国的流行病学调查发现,其发病率呈上升趋势。50年代为71.9/10万,到80年代末90年代初则上升为125.8/10万。女孩比男孩发病率高,发病的高峰年龄为15～19岁之间。晕厥病因复杂,可由血管迷走性晕厥,中枢神经系统疾病、心血管系统疾病、代谢性疾病许多原因引起。除此以外,仍有部分患儿其晕厥的原因始终不明。 近年来,对血管迷走性晕厥的临床研究成为国际小儿心脏病学研究的新热点。其发病机制、临床表现、诊断及治疗各环节均有新概念问世。文详见8、9版《医生论坛》。     

起搏器滞后功能治疗血管迷走性晕厥一例

血管迷走性晕厥(VVS)是一种常见的神经介导性晕厥。发病时，血管扩张、心率骤降．导致心输出量明显降低，血压下降，可突然发生晕厥或晕厥前状态。本文报道1例VVS患者经药物治疗无效，进行双腔起搏治疗。     

77例直立倾斜试验对血管迷走神经性晕厥的诊断

目的探讨直立倾斜试验对血管迷走性晕厥的临床诊断与应用价值。方法采用直立倾斜试验对77例不明原因的晕厥患者先进行基础倾斜试验,阴性者再进行两个阶段的异丙肾上腺素激发试验。结果77例晕厥患者中60例阳性,17例阴性,阳性率占77．9％。结论倾斜试验设备简单,易于操作,是血管迷走性晕厥的比较有效的诊断方法,对不同类型的血管迷走性晕厥确定治疗方案具有指导意义。     

直立倾斜试验对儿童不明原因晕厥的临床应用

目的：为明确不明原固晕厥儿童的病因,协助诊断及治疗。方法：不明原因晕厥的患儿给予仔细询问病史,查体及相关辅助检查后除外神经系统疾病、心脏疾病及代谢病,给予进行直立倾斜试验检查。持续监测心电监护,记录其血压、心率变化。结果：发现血管迷走性晕厥25例。其中心脏抑制型10例（占40％）,血管抑制型11例（占44％）,混合型4例（占16％）。结论：不明原因晕厥的患儿经直立倾斜试验检查,可明确诊断。     

小儿晕厥的病因及分类

晕厥是由多种潜在原因引起的一种临床症状。近几年的研究对其发病机制有了进一步的深化,晕厥发生的原因分为心源性和非心源性。前者更严重,属器质性病变;后者更常见,属功能性心血管疾病,以自主神经介导性晕厥最为常见,主要是由于调节机制中的某个环节出现异常,使心率、血压及中心血容量三者的协调关系失衡所致。其中最为常见的是血管迷走性晕厥,同时要注意和体位性心动过速相区别。     

Randomized comparison of metoprolol versus conventional treatment in preventing recurrence of vasovagal syncope in children and adolescents.

BACKGROUND: Previous studies that have assessed the effects of beta blockers on preventing vasovagal syncope provide conflicting results. We sought to evaluate the effectiveness of metoprolol versus conventional treatment in preventing the recurrence of syncope in children and adolescents. MATERIAL/METHODS: Twenty-eight children and adolescents (8 boys, 20 girls; mean age, 12+/-3 years; age range, 8-17 years) with vasovagal syncope were randomized to receive either metoprolol (metoprolol group; dosage range, 0.5-1.5 mg/kg/d) or conventional treatment (control group) for 1 year. The main outcome measure was the first recurrence of syncope beginning 2 weeks after the start of treatment. The mean follow-up was 22+/-10 months. Time to first recurrence of syncope was analyzed using Kaplan-Meier curves and compared with a log-rank test. RESULTS: The 2 groups did not differ in terms of clinical characteristics. The number of syncopal episodes before tilt testing was 8+/-6 in patients in the metoprolol group and 9+/-6 in patients in the control group (P=0.150). Syncope recurred in 6 of 14 children in the metoprolol group and in 4 of 14 children in the control group. No significant between-group differences were found regarding the probability of freedom from a recurrent episode of syncope during follow-up (metoprolol vs controls, 43% vs 29%; P=0.389), as demonstrated by Kaplan-Meier curve analyses. CONCLUSIONS: Recurrence of vasovagal syncope in children and adolescents treated with metoprolol is similar to that of patients treated with conventional therapy.     

不明原因晕厥儿童血流动力学反应类型与临床表型的关系

目的探讨不明原因晕厥儿童在直立倾斜试验中不同血流动力学类型及其分布,研究不同血流动力学类型与其临床表型之间的关联。方法对100例不明原因晕厥儿童均进行直立倾斜试验(HUT)或舌下含化硝酸甘油激发直立倾斜试验,并根据其在实验中不同的血流动力学反应分为血管迷走性反应型、体位性心动过速综合征反应型、体位性低血压反应型及正常血流动力学反应型4种类型,研究其分布及比较其临床特征。结果100例不明原因晕厥患儿HUT中,50例(50%)出现经典的血管迷走性反应型,33例出现体位性心动过速综合征反应型(33%),15例出现正常反应型(15%),2例出现体位性低血压反应型(2%)。其中在50例血管迷走性反应型中,31例为血管抑制型(31%),12例为混合型(12%),7例为心脏抑制型(7%)。血管迷走性反应型及体位性心动过速反应型的患儿平均年龄大于正常血流动力学反应型的患儿(12±2vs10±3,P<0·01;12±2vs10±3,P<0·01);各种血流动力学类型之间男女性别比没有显著性差异;各种血流动力学类型之间病程的比较亦没有显著性差异;体位性心动过速综合征反应型患儿的晕厥次数显著少于血管迷走性反应型及正常反应型患儿(1±1vs3±3,P<0·01,1±1vs3±2,P<0·01);体位性心动过速综合征反应型基础心率显著快于血管迷走性反应型及正常反应型患儿(81±7vs71±9,P<0·01,81±7vs74±7,P<0·01);基础血压在各种血流动力学类型之间比较都没有显著性差异。发病年龄、性别、病程长短、晕厥次数、基础心率及基础收缩压和舒张压,在血管迷走性反应各亚型之间相比较均无显著性差异。结论不明原因晕厥儿童在直立倾斜试验中可表现出不同的血流动力学反应类型,不同的血流动力学类型之间与其临床表型有一定的关联。     

Pacemaker therapy for prevention of syncope in patients with recurrent severe vasovagal syncope: Second Vasovagal Pacemaker Study (VPS II): a randomized trial

CONTEXT: Three previous small randomized trials have reported that pacemaker therapy is beneficial for patients with severe recurrent vasovagal syncope. However, because these trials were not double blind, they may have been biased in their assessment of outcomes and had a placebo effect of surgery. OBJECTIVE: To determine if pacing therapy reduces the risk of syncope in patients with vasovagal syncope. DESIGN, SETTING, AND PATIENTS: A randomized double-blind trial of pacemaker therapy in outpatients referred to syncope specialists at 15 centers from September 1998 to April 2002. In the year prior to randomization, patients had had a median of 4 episodes of syncope. Patients were followed up for up to 6 months. INTERVENTION: After implantation of a dual chamber pacemaker, 100 patients were randomly assigned to receive dual-chamber pacing (DDD) with rate drop response or to have only sensing without pacing (ODO). MAIN OUTCOME MEASURE: Time to first recurrence of syncope. RESULTS: No patients were lost to follow-up. Of the 52 patients randomized to ODO, 22 (42%) had recurrent syncope within 6 months compared with 16 (33%) of 48 patients in the DDD group. The cumulative risk of syncope at 6 months was 40% (95% confidence interval [CI], 25%-52%) for the ODO group and 31% (95% CI, 17%-43%) for the DDD group. The relative risk reduction in time to syncope with DDD pacing was 30% (95% CI, -33% to 63%; 1-sided P =.14). Lead dislodgement or repositioning occurred in 7 patients. One patient had vein thrombosis, another had pericardial tamponade leading to removal of the pacemaker system, and a third had infection involving the pacemaker generator. CONCLUSIONS: In this double-blind randomized trial, pacing therapy did not reduce the risk of recurrent syncope in patients with vasovagal syncope. Because of the weak evidence of efficacy of pacemaker therapy and the risk of complications, pacemaker therapy should not be recommended as first-line therapy for patients with recurrent vasovagal syncope.     

儿童晕厥诊断和治疗进展

Syncope is a common emergency of children and adolescents,which has serious influence on the quality of life.Neurally-mediated syncope,including postural tachycardia syndrome,vasovagal syncope,orthostatic hypotension and orthostatic hypertension,is the main cause of syncope in children and adolescents.The main manifestations of neurally-mediated syncope are diverse,such as dizziness,headache,chest tightness,chest pain,pale complexion,fatigue,pre-syncope and syncope.Although the clinical manifestations are similar,each subtype of syncope has its hemodynamic feature and optimal treatment option.The diagnosis rate of syncope in children has been greatly improved on account of the development of the diagnostic procedures and methods.In recent years,with the promotion of head-up tilt test and drug-provocated head-up tilt test,the hemodynamic classification of neurally-mediated syncope gets continually refined.In recent years,with the effort of clinicians,an appropriate diagnostic protocol for children with syncope has been established.The initial evaluation consists of history taking,physical examination,standing test and standard electrocardiography.After the initial evaluation,some patients could be diagnosed definitely,such as postural tachycardia syndrome,orthostatic hypotension,and situational syncope.Those with a specific entity causing syncope need selective clinical and laboratory investigations.Patients for whom the cause of syncope remained undetermined should undergo head-up tilt test.The precise pathogenesis of neurally-mediated syncope is not entirely clear.In recent years,studies have shown that neurally-mediated syncope may be related to several factors,including hypovolemia,high catecholamine status,abnormal local vascular tension,decreased skeletal muscle pump activity and abnormal neurohumoral factors.Currently based on the possible pathogenesis,the individualized treatment of neurally-mediated syncope has also been studied in-depth.Generally,the management of neurallymediated syncope includes non-pharmacological and pharmacological interventions.Patient education is the fundamental part above all.In addition to exercise training,the first-line treatments mainly include oral rehydration salts,beta adrenoreceptor blockers,and alpha adrenoreceptor agonists.By analyzing the patient's physiological indexes and biomarkers before treatment,the efficacy of medication could be well predicted.The individualized treatment will become the main direction in the future researches.     

血管迷走性晕厥51例临床分析

目的:探讨血管迷走性晕厥(VVS)的临床特征,提高对本病的认识.方法:回顾性分析51例经直立倾斜试验(HUTT)诊断为VVS的临床表现,比较VVS患者在性别、晕厥诱因和先兆症状等方面的差异.结果:在51例VVS中,女性高于男性1:0.82(P＜0.05 ),发生诱因中以久站及体位改变较常见,先兆症状中以头晕、恶心、呕吐、出冷汗多见.结论:VVS的临床特征虽差异较大,诱因较多,但认识到VVS的发病机制及所表现的不同临床特征,将有助于临床诊治.     

直立倾斜试验加硝酸甘油含化诊断血管迷走性晕厥的临床研究

目的评价硝酸甘油(NTG)含化加异丙肾上腺素倾斜试验(ITTT)诊断血管迷走性晕厥(VS)的价值.方法将72例VS患者和36例正常对照组随机均分成ITTT和ITTT+NTG组.结果ITTT+NTG组敏感性高于ITTT(93.1%和76%,P＜0.05)有显著性差异.结论ITTT+NTG含化是一种安全、耐受性好、敏感性高,特异性强的诊断VS的方法.     

儿童不明原因晕厥诊断的多中心研究

目的 探讨直立倾斜试验(HUTT)对儿童不明原因晕厥的诊断价值.方法 晕厥组为2002年1月至2008年4月在北京、湖南、湖北、上海四地晕厥门诊就诊或住院的379例不明原因晕厥患儿,其中男171例,女208例;年龄3～18岁,平均(12±3)岁.所有患儿通过常规检查仍不能明确患儿晕厥的原因时,进行基础直立倾斜试验(BHUTT)或舌下含化硝酸甘油激发的倾斜试验(SNHUTT)检查.对照组为10名身体健康、无晕厥及晕厥先兆病史的正常儿童,其中男5名,女5名;年龄9～15岁,平均(11.4±2.1)岁,其心血管、神经系统、心电图、超声心动图及X线胸片检查均正常;所有正常儿童均进行BHUTT或SNHUTT.结果 在379例患儿中,286例患儿为自主神经介导性晕厥(75.5%).晕厥患儿中67例为体位性心动过速综合征(17.7%);157例为血管迷走性晕厥血管抑制型(41.4%);14例为血管迷走性晕厥心脏抑制型(3.7%);47例为血管迷走性晕厥混合型(12.4%);1例患儿为直立性低血压(0.3%);93例患儿仍为不明原因晕厥(24.5%).在晕厥组和对照组中,BHUTr的诊断阳性率分别为55.9%和0,SNHUTT的诊断阳性率分别为75.5%和20.0%.BHUTT阳性患者在BHUTT过程中出现阳性反应的时间平均为(16±12)min,阳性反应出现时的体位均为倾斜60°体位;SNHUTT阳性患儿在SNHUTT过程中出现阳性反应的时间平均为(6±4)min,阳性反应出现时的体位均为倾斜60°体位并舌下含化硝酸甘油.结论 应用HUTT可较好地、客观地对儿童自主神经介导性晕厥进行诊断,SNHUTT具有较高的诊断阳性率,明显提高了BHUTT的诊断阳性率,且阳性反应时间明显低于BHUTT.