硝酸异山梨酯舌下含服直立倾斜试验对血管迷走性晕厥诊断价值探讨

目的 :探讨直立倾斜试验 (TTT)前舌下含服硝酸异山梨酯 (ISDN)对诊断血管迷走性晕厥的价值。方法 :将 6 0例血管迷走性晕厥患者分成基础倾斜试验 (BTTT)组和ISDN舌下含服激发倾斜试验 (TTT加IS DN)组。结果 :BTTT组敏感性 37.5 % ,TTT加ISDN组敏感性 77.8% ;两组比较差异有显著性意义 (P <0 .0 1)。结论 :TTT前舌下含服ISDN对诊断血管迷走性晕厥有较好的诊断价值     

异丙肾上腺素消心痛激发倾斜试验对比分析

目的对比分析异丙肾上腺素、消心痛激发倾斜试验的敏感性、特异性、耐受性、安全性的差异。方法选择2001年12月至2006年9月于甘肃省金昌市第二医院就诊并符合条件的33例有晕厥发作史的患者及15例无晕厥史者行基础倾斜试验(BTTT),BTTT阴性者连续2d随机进行异丙肾上腺素倾斜试验(ITTT)和消心痛倾斜试验(GTTT)。结果消心痛组敏感性为65.2%,特异性为93.3%,耐受性较好。异丙肾上腺素组敏感性为69.6%,特异性为86.7%,耐受性较差。结论消心痛倾斜试验与异丙肾上腺素倾斜试验比较敏感性、特异性无明显差异,耐受性、安全性好。     

神经系统疾病

中国医学文摘·内科学2001年第22卷第2期20320011264倾斜试验加舌下含化硝酸甘油诊断血管迷走性.厥/李中莉…刀中国医刊一2000,35(8)一28 舌下含化硝酸甘油的倾斜试验57例中,临床诊断血管迷走神经晕厥43例,无晕厥14例。所患者先做基础倾斜试验(B TTT),试验结果阴性者,行硝酸甘油倾斜试验。结果:43例晕厥病人中,3例BTTT阳性;40例完成硝酸甘油倾斜试验的病例中,29例阳性,阳性率73%。无晕厥14例对照组硝酸甘油倾斜试验阳性率21%。BTTT敏感度7%,特异度100%,诊断价值30%,硝酸甘油倾斜试验以及敏感度78%,特异度78%,诊断价值74%(P均<0.01)。…     

舌下含化硝酸甘油倾斜试验对血管迷走性晕厥的诊断价值

目的 探讨舌下含化硝酸甘油倾斜试验对诊断血管迷走性晕厥（VS）的价值。方法 42例血管迷走性晕厥病人（VS组）及20例无晕厥史健康人（对照组）先行基础倾斜试验（BTTT），阴性者再做舌下含化硝酸甘油倾斜试验（SNTTT）。结果 BTTT阳性诱发率VS组为24％（10／42）对照组为0；两组病人无1例发生体位性低血压。VS组和对照组SNTTT阳性诱发率分别为47％（15／32）、10％（2／20），药物诱发体位性低血压发生率分别为12．5％、10％，两组病人仅有1例出现头痛，但能坚持试验。结论 SNTTT对VS具有较高的敏感性和特异性，副作用小，操作简便省时，是一实用的检查技术。     

异丙肾上腺素倾斜试验对不明原因晕厥患者的影响

观察184例不明原因晕厥患者及37例正常对照组静脉给予异丙肾上腺素(ISO)的影响,其中92例行基础倾斜试验(BTTT),92例行异丙肾上腺素倾斜试验(ITTT)。结果显示:ITTT可使TTT的敏感性升高,特异性下降,且随剂量增加这种变化更为显著。同时发现ITTT最佳时间为10min。ISO可缩短从倾斜到晕厥的时间且不依赖其剂量改变,其次观察到ITTT导致晕厥的有关血流动力学变化与BTTT无差别。     

硝酸甘油激发试验对老年人血管迷走性晕厥的诊断及其影响

为评价硝酸甘油激发实验对老年人血管迷走性晕厥的诊断价值,选取202例不明原因晕厥的病人和76例无晕厥病史的正常人作为对照,按年龄＞60岁和＜60岁各分为两组,分别采用基础倾斜试验(BTTT),BTTT阴性者再给予舌下含服硝酸甘油激发试验(GTTT).     

自主神经在多阶段倾斜试验诱发血管迷走性晕厥中的作用

为评价自主神经在多阶段静滴异丙基肾上腺素倾斜试验（MITTT）诱发血管迷走性晕厥（VS）过程中的作用，分析了10例基础倾斜试验阳性（基础阳性组）、24例HITTT阳性（ISO阳性组）和11例MITTT阴性（对照组）结果患者在基础倾斜前后，阳性反应前或MITTT结束前各4分钟的心率功率谱图。结果显示，基础倾斜前4分钟，三组低频（LF）成分无明显差别（P＞0．05）；基础阳性组高频（HF）成分明显低于另两组（P均＜0．05），LF／HF比值显著高于另两组（P均＜0．05）。基础倾斜后和阳性反应前或MITTT结束前，三级LF成分均增高，但组间比较无明显差别；基础阳性组和ISO阳性组HF成分进行性降低，LF／HF比值进行性显著增大。对照组HF成分在这两个时间段无明显变化，虽然LF／HF比值较基础倾斜前明显增大，但后两个时间段比较并无差别。结果表明，交感神经和副交感神经功能调节障碍在MITTT诱发VS的发生机制中起着重要作用，LF／HF比值能更确切地反映两者在诱发VS中的相互作用。     

直立倾斜试验中药物假阳性反应的表现

目的：研究直立倾斜试验中药物假阳性反应的表现。方法：分析１００例临床表现为血管迷走性晕厥的患者和２１名无晕厥史的正常人直立倾斜试验的结果。结果：药物反应主要表现为①缓慢发展的血压下降，伴随代偿性心率增加；②长时间明显血压下降可出现轻微心动过缓，但心率减慢低于同阶段的３０％；③逐渐出现的症状如头晕、眼花、出汗等晕厥先兆与平时发作的症状不一样。排除药物反应后直立倾斜试验的敏感性为６２．０％，特异性为９０．５％；呈阳性反应者无１例心率≥１５０次／分。结论：正确区别突发的迷走神经反射亢进和药物反应，并且在试验过程中设置１５０次／分的心率上限，是提高直立倾斜试验敏感性又不降低试验特异性的有效方法。     

直立倾斜试验诊断晕厥的探讨

目的研究直立倾斜试验(HUTT)对血管迷走性晕厥(VVS)的诊断价值。方法入选2016年12月至2018年12月在本院就诊,不明原因晕厥,疑似VVS的患者124例,进行HUTT,包括基础倾斜试验(BHUT)和舌下含服硝酸甘油直立倾斜试验(SNHUT)。结果 124例受试者中,阴性反应57例,阳性反应66例,1例为体位性心动过速。阳性组的女性比例较高(p0.05);阳性组最快心率高于阴性组(p0.05),阳性组结束时的心率、收缩压、舒张压均低于最大值(p0.05),也明显低于阴性组(p0.05)。阳性反应中,BHUT就出现阳性反应的5例,占8%;SNHUT阳性61例,占92%;按反应类型:血管抑制性28例(42%),心脏抑制性9例(14%),混合型29例(44%)。3例受试者出现长RR间歇,最长达10.7s,2例受试者舌下含服硝酸甘油后出现腹痛不适。结论 HUTT对VVS具有较好的诊断价值,SNHUT能显著提高VVS的检出率。     

老年原发性高血压患者伴血管迷走性晕厥的相关研究

目的观察直立倾斜试验(HUTT)对老年原发性高血压患者伴血管迷走性晕厥(VVS)阳性诊断情况。方法选择2017年9月～2019年9月于我院住院或门诊诊治的老年原发性高血压疑似VVS患者40例为高血压组,选择同期因晕厥或头晕、黑矇等症状就诊的临床无器质性疾病患者50例为对照组,2组均进行HUTT,包括基础倾斜试验(BTTT)和硝酸甘油倾斜试验(NTTT),记录HUTT阳性率,在HUTT前后检测血浆肾上腺素水平。结果高血压组与对照组HUTT阳性率比较,无显著差异(47.5%vs 54.0%,P=0.540),但高血压组BTTT阳性率显著高于对照组(30.0%vs 10.0%,P=0.016);NTTT阳性率显著低于对照组(17.5%vs 44.0%,P=0.043);HUTT阳性患者中,高血压组试验前肾上腺素水平显著高于对照组(P=0.000),2组试验后较试验前肾上腺素水平均显著升高(P=0.004,P=0.000),对照组试验后肾上腺素水平较高血压组明显升高(P=0.006)。结论部分老年原发性高血压患者出现的晕厥症状是由VVS所致,血浆肾上腺素在VVS发生过程中显著升高。     

影响倾斜试验结果的多因素分析

９２例不明原因晕厥病人及５２名无晕厥病史的正常人对照分为三组，分别采用基础倾斜试验（ＢＴＴＴ）、多阶段异丙肾上腺素─—倾斜试验（ＭＩＴＴＴ）及单阶段异丙肾上腺素─—倾斜试验（ＳＩＴＴＴ）。以实验结果为因变量，以晕厥指数、性别、年龄、基础心率、基础血压及倾斜前心率与基础心率的差值（心率差）为自变量作Ｌｏｇｉｓｔｉｃｓ回归分析。结果：①对所有受试者作Ｌｏｇｉｓｔｉｃｓ回归，晕厥指数及心率差是影响结果的主要因素（Ｐ＝０．０１２和Ｐ＝０．００１）；②病人组结果与上类似（Ｐ＝０．０５２和Ｐ＝０．０３２）；③正常对照，心率差及性别是预测结果的指标。本组结果提示：①晕厥（或先兆）的发病次数及程度以及异丙肾上腺素的应用是影响实验结果的主要因素；②异丙肾上腺素在增加敏感性的同时也增加了假阳性率；③性别也可能是影响倾斜试验（ＴＴＴ）结果的因素之一。     

Neurally mediated syncope and arrhythmias: a study of syncopal patients using the head-up tilt test

Understanding the causes of syncope in patients with arrhythmia is important in determining the therapeutic interventions. Neurally mediated syncope (NMS) was evaluated in 55 patients with various arrhythmias. The head-up tilt test with or without isoproterenol infusion induced NMS in 41 (74%) patients. When these patients was categorized into 3 types, depending on the development of syncope, vasodilatation was significant in a majority of patients. In 46% of patients with tachyarrythmias, NMS was accompanied by an increase in extrasystole. It was concluded that the evaluation of vasodilatation is important for the preventive strategy of NMS in patients with arrhythmias and that NMS may induce arrhythmias.     

Value and limits of the tilt-test in the etiological diagnosis of transient malaise]

This study was undertaken to assess the usefulness of the head-up tilt test in the diagnosis of vasovagal syncope and to evaluate the indications of this investigation. The test consists in a 30 minute period in the horizontal decubitus position followed by a 60 degrees head-up tilt position for 30 minutes. In the 26 subjects in whom the diagnosis of repeated vasovagal syncope had been made on the basis of typical prodromic symptoms after exclusion of all other causes, the test induced a vasodepressive or vagal reaction in 10 cases (38%) 20 +/- 4 minutes after tilting. In 8 patients in whom the test was performed within 48 hours of their syncopal episode, a similar malaise was induced in 7 cases. Twenty patients with repeated malaise without loss of consciousness had no symptoms during the test which was also negative in 10 normal control subjects. In a group of 27 subjects with unexplained syncope after clinical and paraclinical investigations, the test was accompanied by a malaise on five occasions (19%). Using this protocol, the tilt test had good specificity but moderate sensitivity in the diagnosis of vasovagal syncope. Its sensitivity increased when performed within 48 hours of syncope. It is of no value in the diagnosis of recurrent malaise without loss of consciousness.     

Clinical recognition of neurally mediated syncope

BACKGROUND: Most cases of syncope are due to hypotension, with a vasovagal response the commonest single mechanism. Neurally mediated syncope (NMS) is a vasovagal response evoked by common physical or psychological stress factors in susceptible individuals. Although upright tilt table testing (TTT) has been developed to diagnose this condition, the clinical recognition of this common syndrome in the general community remains poor. AIMS: To evaluate the clinical presentation of patients with NMS and pre-syncope, proven by TTT, and compare them to patients with syncope that have a low probability of having NMS (e.g. older patients with cardiac disease and negative TTT). METHODS: Prospective evaluation by questionnaire at the time of TTT, including documentation of presenting symptoms and signs, and provoking factors in consecutive patients. Comparisons between patient groups analyzed using chi-squared tests and logistic regression. RESULTS: Neurally mediated syncope patients were more likely to present with both syncope and pre-syncope, often with prolonged histories of pre-syncope. Certain provoking stress factors were more common in NMS, with multiple factors often present. Most NMS patients had a hypotensive prodrome before syncope, whereas control patients had a higher incidence of syncope without warning. CONCLUSION: Neurally mediated syncope patients present with situational syncope that is not only stereotypical for the individual, but shares common features with other similar patients. While none of the clinical observations is unique to NMS, a carefully detailed history can elicit a convincing diagnostic pattern that can often obviate the need for extensive and expensive investigation, and in younger patients a TTT may not be required to make the diagnosis.     

直立倾斜试验后自主神经功能恢复特点初探

目的通过倾斜试验前后心率变异的变化探讨倾斜试验以及倾斜试验过程中应用异丙肾上腺素（isoproterenol）对自主神经有无较持续的影响及试验的安全性。方法对64例有晕厥史或晕厥前兆患者进行倾斜试验,分为基础倾斜试验（basic tilt table test,BTTT）阳性组5例和阴性组59例,异丙基肾上腺素倾斜试验（isoproterenol tilt table test,ITTT）阳性组31例和阴性组18例。选择倾斜试验前5min及倾斜试验结束后1h5min进行心率变异频域法分析,提取tatol、ulf、vlf、lf、hf、lf/hf6项参数。结果全部病例倾斜试验前后6项参数对比,除vlf外（p=0.011）,其余各项无显著性差异,p〉0.1。BTTT阳性组倾斜试验前后对比,无显著性差异,p〉0.08;BTTT阴性组倾斜试验前后对比,除vlf外（p=0.03）,其余各项无显著性差异,p〉0.1。ITTT阳性组倾斜试验前后对比,无显著性差异,p〉0.1;ITTT阴性组倾斜试验前后对比,除hf外（p=0.013）,其余各项无显著性差异,p〉0.1。BTTT阳性组与阴性组对比,无显著性差异,p〉0.4。ITTT阳性组与阴性组对比,无显著性差异,p〉0.1。结论提示倾斜试验前与倾斜试验结束后1h时,心率变异分析除个别参数外,无显著性差异和规律性变化。倾斜试验结束后1h,自主神经的活动已基本恢复到原来状态。倾斜试验以及倾斜试验过程中应用药物（isoproterenol）对自主神经的影响是暂时的,检查后的安全性较好,对检查程序、病人检查后的留观时间有指导意义。     

An increased endothelial-independent vasodilation is the hallmark of the neurally mediated syncope

Background:

The neurally mediated syncope (NMS) is sustained by complex cardiac and vascular reflexes, acting on and amplified by central autonomic loops, resulting in bradycardia and hypotension.

Hypothesis:

Our aim was to assess whether the pathophysiology of NMS is also related to an abnormal peripheral vasoreactivity.

Methods:

We evaluated by ultrasound the flow‐mediated vasodilation (FMD) and the nitrate‐mediated dilation (NMD) in 17 patients with NMS, induced by drug‐free tilt test in 6 subjects and by nitrate‐potentiated tilt test in the other 11 cases; the syncope was classified as vasodepressive (VD) in 8 cases, cardioinhibitory (CI) in 7, and mixed in 2.

Results:

The FMD was not different from controls (10.2 ± 4.5 vs 11.4 ± 3.9, P = ns), with normal recovery times; the NMD was greater in fainting subjects than in controls (26.7 ± 7.3 vs 19.0 ± 3.6, P < 0.05), with higher values in VD than in CI syncope (31.1 ± 7.0 vs 23.1 ± 5.0, P = ns); compared to controls, subjects with NMS showed normal recovery times after FMD but longer recovery times after nitrate administration (13.0 ± 5.6 vs 6.3 ± 0.7 minutes, P < 0.05).

Conclusions:

The evaluation of endothelial function supports evidence that NMS is characterized by a marked and sustained endothelial‐independent vasodilation, in the presence of a normal FMD; vascular hyperreactivity in response to nitrate administration is particularly overt in vasodepressive syncope and can explain the high rate of responses to nitrate administration during tilt test. © 2011 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Use of nitroglycerin in the active phase of tilt testing: is there a difference in elderly patients?

INTRODUCTION: The importance of tilt testing has been demonstrated in the evaluation of patients with syncope of unknown cause, and it is the gold standard technique for the diagnosis of neurocardiogenic syncope, particularly with the use of pharmacological provocative agents to improve diagnostic accuracy. Stimulation with sublingual nitroglycerin is generally well tolerated and increases test sensitivity, shortening the test duration; this also allows the test to be applied in elderly patients. OBJECTIVES: To evaluate, in a population referred for syncope of unknown etiology, the value of tilt testing with sublingual nitroglycerin and to compare the responses obtained in elderly and younger patients. METHODS: We studied 158 patients who underwent tilt testing using nitroglycerin as a provocative agent. We compared patients aged <65 years (Group A, n=74) and > or =65 years (Group B, n=84). Tilt testing was performed according to the Italian protocol, with continuous monitoring of the electrocardiogram and blood pressure (Task Force Monitor, CNSystems). Only patients who were asymptomatic in the passive phase of the test were included. The test was considered positive for neurocardiogenic response when symptoms were reproduced with bradycardia and/or hypotension; the responses were classified as cardioinhibitory, vasodepressor or mixed. A gradual and parallel decrease in blood pressure after nitroglycerin administration, followed by syncope, was considered an exaggerated response to nitrates. RESULTS: There were no differences in gender distribution between groups. Tilt testing was positive in 57% of group A and 51% of group B patients (p=NS), with an exaggerated response to nitrates in 11% and 16% respectively (p=NS). With regard to neurocardiogenic responses, vasodepression was more frequent in group B (53% vs. 24%; p=0.001), while a mixed response tended to be more frequent in group A (59% vs. 40%; p=0.07), with no significant difference in cardioinhibitory responses (17% in group A vs. 7% in group B; p=NS). CONCLUSIONS: In a population with syncope of unknown origin, tilt testing potentiated with nitroglycerin: a) makes a significant contribution to clarifying diagnosis and is of equal value in both elderly and younger patients; and b) is associated with a higher incidence of neurocardiogenic vasodepressor response in the elderly, although with a similar rate of exaggerated responses to nitrates.     

Methodology of 80 degrees head-up tilt testing with and without low dose isoproterenol provocation in Japanese patients with neurally mediated syncope

The usefulness of 80 degrees head-up tilt testing with and without low dose isoproterenol provocation was evaluated for the diagnosis of neurally mediated syncope (NMS) in Japanese. Head-up tilt testing was performed in 114 consecutive patients with clinical diagnoses of NMS (68 men, 46 women, mean age 46 +/- 21 years), and 57 times in 36 healthy volunteers (26 men, 10 women, mean age 31 +/- 8 years) who had no history of syncope or presyncope. Head-up tilt testing used an 80 degrees angle for 30 minutes (passive tilt), and if the passive tilt resulted in negative response, isoproterenol was infused at 0.01-0.02 microgram/kg/min and the tilt repeated for 10 minutes (isoproterenol tilt). A positive response was defined as the development of syncope or a presyncopal state associated with hypotension, bradycardia or cardiac arrest. The sensitivities of passive tilt testing for a positive response after 5-, 10-, 15-, 20-, 25- and 30-minute tilting were 1%, 9%, 14%, 19%, 24%, and 28%, respectively, and specificities after 5-, 10-, 15-, 20-, 25- and 30-minute tilting were 100%, 95%, 91%, 88%, 86%, and 84%, respectively. The sensitivities of isoproterenol tilt testing with 0.01 and 0.02 microgram/kg/min were increased to 37% and 48%, respectively. This improvement was statistically significant between the passive tilt and isoproterenol tilt testing with a dose of 0.02 microgram/kg/min (p < 0.01). However, specificities were comparable with those of the passive tilt testing (84% and 82%, respectively). In conclusion, 80 degrees passive tilt testing for 30 minutes showed a low sensitivity (28%) but acceptable specificity (84%). Low-dose isoproterenol provocation was useful for improving sensitivity (48%) while maintaining a comparable specificity (82%).