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。     

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。     

儿童不明原因晕厥诊断及血流动力学类型的多中心研究

目的探讨不明原因晕厥患儿的诊断及各种血流动力学类型的变化规律。方法2000-05—2006-04,对在北京、湖南、湖北三地就诊或住院的208例不明原因晕厥或接近晕厥患儿[男87例,女121例;年龄3～19(11.66±2.72)岁],进行诊断学研究并对血流动力学类型进行检测,采用SPSS10.0软件进行统计。结果不明原因晕厥的患儿以女性居多,208例患儿中女性121例(58.2%),男性87例(41.8%);不明原因晕厥的患儿年龄近似正态分布,平均年龄11.66岁。208例不明原因晕厥患儿经直立倾斜试验(HUT)诊断,155例为阳性;基础直立倾斜试验(BHUT)的诊断阳性率达50.48%(105/208);舌下含化硝酸甘油激发的直立倾斜试验(SNHUT)的阳性率为74.52%(155/208),舌下含化硝酸甘油激发的直立倾斜试验的敏感度及诊断价值均为74.52%;在诊断为阳性的患儿中,体位性心动过速类型占60例(28.8%),血管抑制型72例(34.6%),心脏抑制型5例(2.4%),混合型18例(8.7%);53例经BHUT及SNHUT诊断为阴性的患儿,其血流动力学类型正常(25.5%)。不同年龄组(年龄<12岁和年龄≥12岁)间患儿性别比较差异无显著性(P>0.05);两组(年龄<12岁和年龄≥12岁)血流动力学类型分布差异有显著性(P<0.05);不同性别患儿血流动力学类型分布差异无显著性(P>0.05)。患儿主诉症状不同(主诉头晕、未晕倒和主诉晕厥发作)血流动力学类型分布差异有显著性(P<0.05);晕厥持续时间不同(持续时间≤5min和持续时间>5min)血流动力学类型分布差异无显著性;血流动力学类型不同,患儿的晕厥诱因、晕厥先兆、晕厥伴随症状及晕厥后状态不同。结论不明原因晕厥好发于女孩,并且高峰年龄接近12岁,直立倾斜试验对于此病的诊断阳性率较高;不同年龄段的患儿血流动力学类型分布不同。对于不明原因晕厥患儿,应采用HUT进行诊断并判断其血流动力学类型,以便于合理用药治疗。     

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。     

血浆催乳素及皮质醇与儿童血管迷走性晕厥的相关性

目的分析血管迷走性晕厥(VVS)患儿直立倾斜试验(HUT)中血浆催乳素(PRL)及皮质醇(Cor)的变化, 探讨二者与VVS的相关性。方法回顾性选取2019年5月至2020年5月首都儿科研究所附属儿童医院完善HUT阳性确诊为VVS的75例患儿设为VVS组, 选取同期HUT阴性的29例健康儿童设为健康对照组。采用无创连续血压监测仪实时监测心率(HR)、收缩压(SBP)及舒张压(DBP), 比较HUT平卧位及HUT阳性反应时HR、SBP及DBP的变化。采用电化学发光法测定HUT平卧位及HUT阳性反应时的PRL及Cor水平, 计算HUT平卧位及HUT阳性时PRL及Cor的变化差值(ΔPRL、ΔCor)。组间比较采用独立样本t检验及Mann-Whitney秩和检验, 采用受试者工作特征曲线(ROC)分析ΔPRL对VVS的预测价值。结果 VVS组与健康对照组年龄、性别、体质量指数、血电解质比较, 差异均无统计学意义(均P>0.05);VVS组亚型间(血管抑制型、混合型、心脏抑制型)晕厥频率、晕厥病程比较, 差异均无统计学意义(均P>0.05)。VVS组HUT后PRL高于健康对照组[3...     

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.     

自主神经介导性晕厥儿童在直立倾斜试验中阳性反应与并发症的早期发现和处理

目的探讨如何早期发现并及时处理自主神经介导性晕厥(NMS)患儿在直立倾斜试验(HUTT)中的阳性反应与并发症。方法回顾分析行HUTT检查阳性确诊NMS患儿的临床资料。结果 201例NMS患儿中,男性95例、女性106例,年龄7岁4月～16岁9月,血管迷走性晕厥(VVS)103例、体位性心动过速综合征(POTS)98例。患儿在HUTT中,晕厥再现5例(2.5%),均为VVS;出现并发症200例(99.5%),其中窦性心动过速182例(90.5%)、窦性心动过缓38例(18.9%),包括心率骤升骤降20例(10.0%),心脏停搏2例(1.0%),交界性逸搏心律2例(1.0%),II度房室传导阻滞1例(0.5%),房性早搏1例(0.5%),抽搐2例(1.0%),暂时性失语2例(1.0%)。达到阳性反应后迅速将倾斜床恢复至水平位,晕厥者予以吸氧并抬高及按摩双下肢,心脏停搏者予以胸外心脏按压,部分清醒后予口服牛奶等处理,全部患儿短时间内临床表现消失,意识、心率、血压、心电图恢复正常,无遗留后遗症及死亡病例。181例(90.0%)患儿在HUTT中有晕厥先兆,108例(53. 7%)先有晕厥先兆其后达到阳性反应标准,其中103例在晕厥先兆出现后的8分钟内达到阳性反应标准;47例(23.4%)晕厥先兆与到阳性反应几乎同时出现。结论 NMS儿童在HUTT时存在一定风险,早期发现并及时处理阳性反应和并发症,是降低试验风险的关键。     

血管迷走性晕厥患儿40例

目的探讨不同类型血管迷走性晕厥(VVS)患儿的临床特征及实验室检查指标间的差异。方法经常规病史询问、体格检查、卧立位血压、辅助检查、直立倾斜试验(HUT)确诊的VVS患儿40例,比较不同类型患儿的临床特征及实验室指标间的差异。结果VVS患儿的血流动力学类型以血管抑制性为主。不同类型VVS患儿的临床特征,包括晕厥的诱因、先兆、发作频率、持续时间、基础心率、血压及血清电解质水平等均无显著差异。结论血管抑制型反应是血管迷走性晕厥患儿的主要血流动力学类型。     

儿童体位性心动过速综合征的临床特征及随访研究

目的　探讨儿童体位性心动过速综合征 (POTS)的临床特征、诊断标准及治疗方案。方法　以符合诊断标准的 28例POTS患儿为研究对象,分析年龄分布、病程及基础血流动力学指标,同时观察其各种临床表现的发生频率及诊治效果。结果　诊断为POTS的患儿 28例,占 88例不明原因晕厥或起立后头晕就诊患儿的 32%,其中男 11例,女 17例。男∶女约为 1∶1.5。年龄 6~16岁,平均为(11.6±2.2)岁,其中 6~10岁 5例,占 18%, 10~16岁(包括 10岁)23例,占 82%。病程为 1个月~6年,平均(13.3±19.6)个月,半数以上在 6个月以内;最常见的临床表现为起立后出现头晕或眩晕、晕厥、胸闷、头痛、心悸、面色改变、视物模糊、倦怠、晨起不适等直立不耐受或直立调节障碍症状, 14例伴有恶心或呕吐等消化道症状;在直立试验(先安静平卧 10min,然后直立 10min)或直立倾斜试验(HUT)过程中,POTS患儿最常见的异常表现为在直立或倾斜后 10min内,心率增加≥35次 /min,部分患儿心率最大值≥120次 /min,出现异常表现的时间平均为 5min左右;但仅有 10例的患儿在直立后即出现异常表现, 18例患儿需要HUT确定诊断。12例POTS患儿曾被误诊为癫痫或心肌炎,误诊率达 43%。经过生活指导治疗及药物治疗的综合治疗后,大多数患儿症状可缓解或消失。结论　POTS常见     

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。     

Head-up tilt test: A highly sensitive,specific test for children with unexplained syncope

Unexplained syncope may cause diagnostic and therapeutic problems in children. The head-up tilt test has been shown to be a useful tool for investigating unexplained syncope, especially for diagnosis of neurally mediated syncope. In this study 20 patients aged 9–18 years (12.0±2.5 years) with syncope of unknown origin and 10 healthy age-matched children were evaluated by head-up tilt to 60° for 25 minutes. The test was considered positive if syncope or presyncope developed in association with hypotension, bradycardia, or both. If tilting alone did not induce symptoms (syncope or presyncope), isoproterenol infusion was administered with increasing doses (0.02–0.08 μg/kg per minute). During the tilt test, symptoms were elicited in 15 (75%) of the patients with unexplained syncope but in only one (10%) of the control group (p<0.001). The sensitivity of the test was 75% and its specificity 90%. Three patterns of response to upright tilt were observed in symptomatic patients: vasodepressor pattern with an abrupt fall in blood pressure in 67%; cardioinhibitory pattern with profound bradycardia in 6%; and mixed pattern in 27%. In patients with positive head-up tilt, there were sudden decreases in systolic blood pressure (from 130±15 to 61±33 mmHg) and in mean heart rate (from 147±26 to 90±38 beats per minute) (p<0.001) during symptoms. Treatments with atenolol 25 mg/day has shown complete suppression of syncope in positive responders during a mean follow-up period of 18±6 months. The head-up tilt test is a noninvasive, sensitive, specific diagnostic tool for evaluating children with unexplained syncope.     

A matched case control study of orthostatic intolerance in children/adolescents with chronic fatigue syndrome

This study aimed to define cardiovascular and heart rate variability (HRV) changes following head-up tilt (HUT) in children/adolescents with chronic fatigue syndrome (CFS) in comparison to age- and gender-matched controls. Twenty-six children/adolescents with CFS (11-19 y) and controls underwent 70-degree HUT for a maximum of 30 min, but returned to horizontal earlier at the participant's request with symptoms of orthostatic intolerance (OI) that included lightheadedness. Using electrocardiography and beat-beat finger blood pressure, a positive tilt was defined as OI with 1) neurally mediated hypotension (NMH); bradycardia (HR <75% of baseline), and hypotension [systolic pressure (SysP) drops >25 mm Hg)] or 2) postural orthostatic tachycardia syndrome (POTS); HR increase >30 bpm, or HR >120 bpm (with/without hypotension). Thirteen CFS and five controls exhibited OI generating a sensitivity and specificity for HUT of 50.0% and 80.8%, respectively. POTS without hypotension occurred in seven CFS subjects but no controls. POTS with hypotension and NMH occurred in both. Predominant sympathetic components to HRV on HUT were measured in CFS tilt-positive subjects. In conclusion, CFS subjects were more susceptible to OI than controls, the cardiovascular response predominantly manifest as POTS without hypotension, a response unique to CFS suggesting further investigation is warranted with respect to the pathophysiologic mechanisms involved.     

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.     

Physiologic neurocirculatory patterns in the head-up tilt test in children with orthostatic intolerance

Background: Orthostatic intolerance (OI) is a common clinical manifestation in clinical pediatrics. The head‐up tilt (HUT) table test is considered the standard of orthostatic assessment, but the physiologic neurocirculatory profile during HUT has not been fully realized in children with OI. The present study, therefore, was designed to investigate the physiologic patterns that occur during HUT in children with OI. Methods: Ninety children (56 girls; mean age, 11.6 ± 2.3 years) with OI underwent HUT under quiet circumstances. Blood pressure and heart rate were monitored simultaneously. Results: Forty‐nine children with OI (54.4%) had vasovagal response with HUT testing; 33 (36.7%), vasodepressor response; six (6.7%), cardioinhibitory response; and 10 (11.1%), mixed response. Twenty‐eight children (31.1%) had postural orthostatic tachycardia; one (1.1%), orthostatic hypotension (OH); and 12 (13.3%), normal physiologic response. Patterns of cerebral syncope response and chronotropic incompetence were not observed. Conclusions: Classical vasovagal response was the major physiologic pattern seen in children with OI during HUT testing, and postural orthostatic tachycardia response ranked second.     

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.     

Usefulness of the Head-Up Tilt Test in Distinguishing Neurally Mediated Syncope and Epilepsy in Children Aged 5–20 Years Old

Many nonepileptic disorders may mimic epilepsy by history or clinical presentation. Neurally mediated syncope is one of the most important conditions that might be difficult to differentiate from epilepsy on clinical grounds. We investigated the value of the head-up tilt test (HUT) to diagnose syncope in epileptic children. We studied 40 patients (18 girls and 22 boys) between 5 and 20 years old (mean, 11.5 ± 3.5) who had a previous diagnosis of epilepsy. All patients underwent a HUT test. The HUT test was positive in 26 patients (65%). No statistical difference was observed between the tilt positive and negative groups in sex, age, provocating factors, associated symptoms, family history of syncope and heart disease, findings in physical examination, and electroencephalogram result. There was a history in favor of true syncope in 58% of tilt positive patients compared to 14% of tilt negative patients (p < 0.05). Also, family history of seizure was more frequent in tilt positive patients (p < 0.05). After 18 ± 6 months of follow-up, 18 of 26 patients with a positive tilt test were completely asymptomatic. Inadequate history taking and overemphasis on positive family history for seizures were important causes of misdiagnosis of epilepsy in our study. The HUT test is a simple, noninvasive diagnostic tool for distinguishing syncope and epilepsy in children and should be considered early in the diagnostic plan and for determining management of selected patients with a history of drop attack and loss of consciousness.     

Orthostatic intolerance in adolescent chronic fatigue syndrome

OBJECTIVES: To demonstrate the association between orthostatic intolerance and the chronic fatigue syndrome (CFS) in adolescents and to delineate the form that orthostatic intolerance takes in these children. STUDY DESIGN: We investigated the heart rate and blood pressure (BP) responses to head-up tilt (HUT) in 26 adolescents aged 11 to 19 years with CFS compared with responses in adolescents referred for the evaluation of simple faint and to responses in 13 normal healthy control children of similar age. RESULTS: A total of 4/13 of the controls and 18/26 simple faint patients experienced typical faints with an abrupt decrease in BP and heart rate associated with loss of consciousness. One CFS patient had a normal HUT. A total of 25/26 CFS patients experienced severe orthostatic symptoms associated with syncope in 7/25, orthostatic tachycardia with hypotension in 15/25, and orthostatic tachycardia without significant hypotension in 3/25. Acrocyanosis, cool extremities, and edema indicated venous pooling in 18/25. None of the control or simple faint patients experienced comparable acral or tachycardic findings. CONCLUSIONS: We conclude that chronic fatigue syndrome is highly related to orthostatic intolerance in adolescents. The orthostatic intolerance of CFS often has heart rate and BP responses similar to responses in the syndrome of orthostatic tachycardia suggesting that a partial autonomic defect may contribute to symptomatology in these patients.