直立倾斜试验对不明原因晕厥的临床应用

目的探讨直立倾斜试验在不明原因晕厥患者中筛查血管迷走性晕厥的价值。方法对52例不明原因晕厥患者进行直立倾斜试验,严密观察其血压、心率的变化。结果52例患者中阳性30例,占57．7％;基础倾斜试验阳性5例,异丙肾上腺素激发倾斜试验阳性25例;其中,心脏抑制型5例（16．7％）,血管抑制型8例（26．6％）,混合型17例（56．7％）。结论直立倾斜试验能简捷、有效地把血管迷走性晕厥从不明原因晕厥患者中筛查出来,明确诊断,值得临床推广应用。     

直立倾斜试验在不明原因晕厥中的应用108例分析

目的探讨直立倾斜试验(HUTT)在不明原因晕厥患者中筛查血管迷走性晕厥的价值。方法对108例不明原因晕厥患者进行直立倾斜试验,严密观察其血压、心率、心电图的变化。结果 108例中阳性62例,占57.4%;基础倾斜试验阳性21例(19.4%),硝酸甘油激发倾斜试验阳性41例(38%);其中,心脏抑制型12例(19.3%),血管抑制型20例(32.3%),混合型30例(48.4%)。结论直立倾斜试验能够简便的把血管迷走性晕厥从不明原因晕厥患者中筛查出来,明确诊断,值得广泛推广。     

直立倾斜试验的监护与观察

直立倾斜试验是目前确诊血管迷走神经性晕厥的重要手段.其原理是利用体位由低平突然倾斜而激发自主神经的调节反射,诱发心血管系统异常变化致晕厥发作来诊断血管迷走性晕厥.本文总结了对58例不明原因晕厥患者施行的直立倾斜试验的护理配合体会.现报告如下:     

成年人直立性心动过速与血管迷走性晕厥的相关研究

目的探讨成年人直立性心动过速综合征与血管迷走性晕厥的相关性。方法选择直立性心动过速疑似患者,利用改良的基础倾斜试验方案予以确诊,随后进行含化硝酸甘油倾斜试验,若出现晕厥,口服心得安后再行倾斜试验全过程。结果93例疑似患者中78例发生直立性心动过速,阳性率83.65%;在随后的硝酸甘油倾斜试验中有63例出现晕厥,阳性率80.77%;上述两种阳性患者于第4天口服心得安30mg后再行试验无1例出现直立性心动过速和晕厥。结论改良的基础倾斜试验是诊断直立性心动过速的最佳方案,成年人直立性心动过速与血管迷走性晕厥的发生密切相关。     

血管迷走性晕厥病人行直立倾斜试验的护理

晕厥是临床上较为常见的一种综合征。血管迷走性晕厥在不明原因的晕厥中约占70％，直立倾斜试验已逐渐成为诊断血管迷走性晕厥的重要手段。血管迷走性晕厥病人在日常生活中以及在直立倾斜试验前后的护理干预较为重要。现就本院收治的128例病人的情况总结如下。     

直立倾斜试验对恶性血管迷走性晕厥的诊断价值及治疗

晕厥是常见的综合征,30%～60%经各方面检查不能明确病因,可能属于神经介导的反射性的,短暂的低血压及心动过缓所致.神经介导的晕厥中常见的为血管迷走性晕厥.有人认为是心源性猝死的一种潜在原因.有报道心源性晕厥一年病死率为30%,非心源性晕厥者为12%,而不明原因者为6%.为了估价这种可能性和检测血管迷走性心源停搏的特征,本试验对32例原因不明晕厥者采用直立倾斜试验方法作诱发试验,以识别恶性血管迷走性晕厥,并进行药物治疗评价.     

直立倾斜试验对儿童晕厥患者的临床应用

目的观察直立倾斜试验对儿童晕厥患者的诊断应用价值。方法对32例不明原因晕厥患儿进行直立倾斜实验的结果进行回顾性分析。结果32例患儿中阳性23例,占71.88%,基础实验阳性9例,占28.12%,异丙肾上腺素诱发14例,占43.75%。结论直立倾斜试验对儿童血管迷走性晕厥的诊断有重要临床应用价值,加用异丙肾上腺素可提高试验的阳性率。     

血管迷走性晕厥病人行直立倾斜试验的护理

晕厥是临床上较为常见的一种综合征。血管迷走性晕厥在不明原因的晕厥中约占 70 % [1] ,直立倾斜试验已逐渐成为诊断血管迷走性晕厥的重要手段。血管迷走性晕厥病人在日常生活中以及在直立倾斜试验前后的护理干预较为重要。现就本院收治的 12 8例病人的情况总结如下。1　资料与     

直立倾斜试验检查不明原因晕厥的临床意义

目的探讨直立倾斜试验诊断不明原因晕厥的临床意义。方法对我院2005年10月~2007年12月48例不明原因晕厥患者行基础试验或药物激发试验,持续监测心率和血压,记录阳性反应率。结果本组23例阳性,总阳性率为47.92%,其中基础试验阳性7例,药物激发试验阳性16例。分型:混合型13例,占56.52%;血管抑制型6例,占26.09%;心脏抑制型4例,占17.39%。对阳性患者给予普萘洛尔10 mg每日3次短期口服,其中2例心脏抑制型植入具有频率骤降功能的起搏器进行治疗,随访3年均未再发晕厥。结论直立倾斜试验有助于阐明血管迷走性晕厥的病理生理机制,为临床诊治提供重要线索。     

倾斜试验在诊断血管迷走性晕厥中的应用及其护理

晕厥是由多种原因导致的突然短暂的意识丧失 ,能自行恢复的无神经定位体征的一组临床表现。血管迷走性晕厥是一种神经反射性晕厥。直立倾斜试验 (head -uptilttest ,HUT )对不明原因晕厥的诊断有很大的临床价值[1] ,HUT阳性结果再现了血管迷走性晕厥症状[2 ] ,系目前诊断血管迷走性晕厥的准金标准。我科自 2 0 0 1年 3月— 2 0 0 2年 3月对符合受试指证的不明原因的晕厥病人 3 0例做了HUT。现将检查护理方法介绍如下。1　对象与方法1.1　对象　 2 0 0 1年 3月— 2 0 0 2年 3月我科收治的不明原因晕厥病人 3 0例 ,其中男 12例 ,女 18例 ,…     

倾斜训练预防血管迷走神经性晕厥发生的疗效观察

[目的]探讨倾斜训练预防血管迷走神经性晕厥发生的效果.[方法]将66例倾斜试验阳性、近期多次发作的血管迷走神经性晕厥患者随机分为倾斜训练组、药物治疗组（美托洛尔）和对照组,治疗2周后复查直立倾斜试验并随访.[结果]除2例因心动过缓退出试验外,余64例中倾斜训练组的直立倾斜试验转阴率为86.4%（19/22）、药物治疗组、对照组的直立倾斜试验转阴率分别为25.0%（5/20）、18.2%（4/22）.倾斜训练组与其他两组比较有统计学差异（P〈0.05）,药物治疗组与对照组比较无统计学差异（P〉0.05）.治疗随访半年,倾斜训练组晕厥复发率为9.1%（2/22）,药物治疗组、对照组晕厥复发率分别为40.0%（8/20）、77.3%（17/22）.三组间比较分别有统计学差异（P〈0.05）,但倾斜训练组晕厥复发率最低.[结论]倾斜训练可更好的预防血管迷走神经性晕厥患者的晕厥发生.     

Stepwise Evaluation of Unexplained Syncope in a Large Ambulatory Population

Background: Up to 60% of syncopal episodes remain unexplained. We report the results of a standardized, stepwise evaluation of patients referred to an ambulatory clinic for unexplained syncope.
Methods and Results: We studied 939 consecutive patients referred for unexplained syncope, who underwent a standardized evaluation, including history, physical examination, electrocardiogram, head-up tilt testing (HUTT), carotid sinus massage (CSM) and hyperventilation testing (HYV). Echocardiogram and stress test were performed when underlying heart disease was initially suspected. Electrophysiological study (EPS) and implantable loop recorder (ILR) were used only in patients with underlying structural heart disease or major unexplained syncope. We identified a cause of syncope in 66% of patients, including 27% vasovagal, 14% psychogenic, 6% arrhythmias, and 6% hypotension. Noninvasive testing identified 92% and invasive testing an additional 8% of the causes. HUTT yielded 38%, CSM 28%, HYV 49%, EPS 22%, and ILR 56% of diagnoses. On average, patients with arrhythmic causes were older, had a lower functional capacity, longer P-wave duration, and presented with fewer prodromes than patients with vasovagal or psychogenic syncope.
Conclusions: A standardized stepwise evaluation emphasizing noninvasive tests yielded 2/3 of causes in patients referred to an ambulatory clinic for unexplained syncope. Neurally mediated and psychogenic mechanisms were behind >50% of episodes, while cardiac arrhythmias were uncommon. Sudden syncope, particularly in older patients with functional limitations or a prolonged P-wave, suggests an arrhythmic cause.     

Tilt-induced pseudosyncope

Using the head-up tilt test (HUTT) we evaluated 986 consecutive patients affected by unexplained syncope. In 266 patients the test induced bradycardia and/or hypotension resulting in syncope or presyncope, thus allowing a diagnosis of neurally mediated syncope. In three other patients (0.3% of the entire population and 1% of the all positive tests) HUTT provoked loss of consciousness despite no significant change in heart rate and/or blood pressure. In all three cases unconsciousness was prolonged and no pathological finding was present except lack of response. This phenomenon has been defined as 'pseudosyncope' and related to psychiatric illness. Pseudosyncope induced by HUTT reproduced the clinical events, so the test outcome was considered a true positive response. Our experience suggests that HUTT may contribute to the recognition of psychiatric disorder in some patients affected by unexplained syncope.     

不明原因晕厥相关性躯体意外伤害

目的探讨不明原因晕厥相关性躯体意外伤害情况。方法对不明原因晕厥患者(n=351)详细询问病史,包括晕厥发作时躯体意外伤害事件的发生情况,并行倾斜试验(HUTT)检查明确诊断。结果①31例(8.8%)患者有晕厥相关性躯体意外伤害,HUTT阳性患者中19例(11.5%)存在晕厥相关性躯体意外伤害;②晕厥致躯体意外伤害大多较轻,少数患者会发生严重伤害;③发生晕厥相关性躯体意外伤害者男性较多,年龄段以9~13岁居多;④躯体意外伤害患者HUTT反应类型以血管抑制型为主,混合型次之,心脏抑制型最少。结论晕厥相关性躯体意外伤害事件的发生是随机的,大部分患者伤害较轻,个别患者会发生严重意外伤害。强调对不明原因晕厥患者重视HUTT检查,对确诊的血管迷走性晕厥(VVS)患者实施早期干预,将躯体意外伤害事件的发生降至最低限度。     

Tilt table testing,methodology and practical insights for the clinic

Tilt table testing (TTT) has been used for decades to study short-term blood pressure (BP) and heart rate regulation during orthostatic challenges. TTT provokes vasovagal reflex in many syncope patients as a background of widespread use. Despite the availability of evidence-based practice syncope guidelines, proper application and interpretation of TTT in the day-to-day care of syncope patients remain challenging. In this review, we offer practical information on what is needed to perform TTT, how results should be interpreted including the Vasovagal Syncope International Study classification, why syncope induction on TTT is necessary in patients with unexplained syncope and on indications for TTT in syncope patient care. The minimum requirements to perform TTT are a tilt table with an appropriate tilt-down time, a continuous beat-to-beat BP monitor with at least three electrocardiogram leads and trained staff. We emphasize that TTT remains a valuable asset that adds to history building but cannot replace it, and highlight the importance of recognition when TTT is abnormal even without syncope. Acknowledgement by the patient/eyewitness of the reproducibility of the induced attack is mandatory in concluding a diagnosis. TTT may be indicated when the initial syncope evaluation does not yield a certain, highly likely, or possible diagnosis, but raises clinical suspicion of (1) reflex syncope, (2) orthostatic hypotension (OH), (3) postural orthostatic tachycardia syndrome or (4) psychogenic pseudosyncope. A therapeutic indication for TTT in the patient with a certain, highly likely or possible diagnosis of reflex syncope, may be to educate patients on prodromes. In patients with reflex syncope with OH TTT can be therapeutic to recognize hypotensive symptoms causing near-syncope to perform physical countermanoeuvres for syncope prevention (biofeedback). Detection of hypotensive susceptibility requiring therapy is of special value.     

Evaluation of syncope

Syncope is a transient and abrupt loss of consciousness with complete return to preexisting neurologic function. It is classified as neurally mediated (i.e., carotid sinus hypersensitivity, situational, or vasovagal), cardiac, orthostatic, or neurogenic. Older adults are more likely to have orthostatic, carotid sinus hypersensitivity, or cardiac syncope, whereas younger adults are more likely to have vasovagal syncope. Common nonsyncopal syndromes with similar presentations include seizures, metabolic and psychogenic disorders, and acute intoxication. Patients presenting with syncope (other than neurally mediated and orthostatic syncope) are at increased risk of death from any cause. Useful clinical rules to assess the short-term risk of death and the need for immediate hospitalization include the San Francisco Syncope Rule and the Risk Stratification of Syncope in the Emergency Department rule. Guidelines suggest an algorithmic approach to the evaluation of syncope that begins with the history and physical examination. All patients presenting with syncope require electrocardiography, orthostatic vital signs, and QT interval monitoring. Patients with cardiovascular disease, abnormal electrocardiography, or family history of sudden death, and those presenting with unexplained syncope should be hospitalized for further diagnostic evaluation. Patients with neurally mediated or orthostatic syncope usually require no additional testing. In cases of unexplained syncope, further testing such as echocardiography, grade exercise testing, electrocardiographic monitoring, and electrophysiologic studies may be required. Although a subset of patients will have unexplained syncope despite undergoing a comprehensive evaluation, those with multiple episodes compared with an isolated event are more likely to have a serious underlying disorder.     

直立不耐受儿童直立倾斜试验的性别和年龄差异

目的 探讨直立不耐受(OI)儿童直立倾斜试验(HUTT)的性别和年龄差异.方法 2004-01～2009-06在中南大学湘雅二医院儿童晕厥专科门诊就诊或住院的具有不明原因晕厥、头晕、胸闷、胸痛或心悸等OI症状的儿童728例,年龄3～17 岁[平均(10.67±2.85)岁],男388例,女340例.其中＜12岁416例,年龄3～11岁[平均(8.69±1.86)岁];≥12岁312例,年龄12～17岁[平均(13.30±1.50)岁].经详细询问病史、体格检查、心脏X线、超声心动图、常规12导联心电图、脑电图、头颅CT、血液生化(空腹血糖、心肌肌钙蛋白I)等排除器质性心脏病及其他疾病后行HUTT检查.结果 ①HUTT阳性率:60.71%(442/728),女性高于男性(P<0.01);≥12岁组高于＜12岁组(P<0.01).HUTT阳性率在＜12岁组男性低于女性(P<0.05),≥12岁组男性与女性比较差异无统计学意义(P＞0.05),≥12岁组男性及女性分别高于＜12岁组男性及女性(P均<0.01).②HUTT类型:以血管迷走性晕厥(VVS)多见(59.95%,265/442),其次为体位性心动过速综合征(POTS,37.56%,166/442)及体位性低血压(OH,2.49%,11/442).HUTT类型分布在男性与女性之间及＜12岁组与≥12岁组之间比较差异均无统计学意义(P均＞0.05).HUTT类型分布在男性及女性＜12岁组与≥12岁组之间比较差异无统计学意义(P均＞0.05).HUTT类型分布在＜12岁组及≥12岁组男性与女性之间比较差异无统计学意义(P均＞0.05).结论 具有不明原因晕厥、头晕、胸闷、胸痛或心悸等OI症状的儿童HUTT阳性率存在性别和年龄差异,但HUTT类型分布未见明显的性别和年龄差异.     

血管迷走性晕厥患者直立倾斜试验反应类型转变的机制

目的 探讨血管迷走性晕厥(VVS)患者直立倾斜试验(HUTT)反应类型发生转变的机制.方法 2003-06～2008-04在我院晕厥专科门诊就诊或住院的以不明原因晕厥或晕厥先兆为主诉的患者50例,年龄7-53岁[平均(14.82±8.55)岁],男性15例,女性35例,HUTT检查为阳性,诊断为VVS.经健康教育与药物干预治疗后,随诊并追踪复查HUTT.HUTT采用基础直立倾斜试验(BHUT)及舌下含化硝酸甘油直立倾斜试验(SNHUT),比较初诊检查与重复检查的HUTr反应类型.结果 第一次HUTT复查50例中有5例(10%)HUTT反应类型发生改变,第二次HuTT复查10例中有2例(20%)HUTT反应类型发生改变.HUTT反应类型发生转变见于心脏抑制型转变为混合型、血管抑制型转变为混合型、混合型转变为心脏抑制型、混合型转变为血管抑制型.结论 VVS患者随访过程中HUTT反应类型可发生转变,HUTT反应类型转变的机制受患者自主神经功能状态、干预治疗方法及患者的耐受性等多因素影响.     

Heart rate variability and autonomic nervous system changes in children with vasovagal syncope

The aim of this study was to evaluate the HRV at rest and during tilt test (HUTT) in children with a history of vasovagal syncope and to link the HRV indices with the clinical results of the test. HRV indices were assessed in the supine position and during the initial 5 minutes of the 60-degree HUTT in 49 patients (33 females, 16 males, mean age of 13 +/- 2.8 years) who were evaluated for recurrent syncope. The positive to negative results of the test were 21 to 28. The normalized power of high frequency component (npHF) decreased, normalized power of low frequency component (npLF) and the LF:HF ratio increased during HUTT of tilt-positive patients (P < 0.05 for each parameter). Parallel changes, but to a lesser degree, were observed for similar HRV parameters of tilt-negative patients. In addition, the HF and all the time-domain indices decreased significantly (P < or = 0.05) during HUTT in the latter group. When the tilt-positive and -negative patients were compared, the npHF was lower (P = 0.002), npLF and LF:HF ratio were higher (P = 0.01 and P = 0.001, respectively) during the test in tilt-positive patients, reflecting increased sympathetic tone in this group. A cut-off point for LF:HF was assigned as 2.7 for differentiating tilt-negative and tilt-positive results. The specificity, sensitivity, and positive and negative predictive values of this cut-off point were calculated as 93%, 52%, 85%, and 41%, respectively. Patients with vasovagal syncope show variations in vagal autonomic tone and appear to be more prone to syncope when their sympathetic tone is elevated at the beginning of the test. LF:HF > 2.7 is a specific marker (specificity 93%) and can correctly predict a positive tilt test in 85% of patients.     

Predictors of response to the head-up tilt test in patients with unexplained syncope or presyncope

BACKGROUND: Unexplained syncope is a relatively frequent symptom, mostly caused by a neurocardiogenic reaction. The purpose of this study was to determine predictors of response to head-up tilt testing (HUTT) in patients with unexplained syncope or presyncope. METHODS: HUTT was done in 640 consecutive patients with unexplained syncope or presyncope (393 men, mean age 45+/-19 years) after initial workup including history, physical examination, and appropriate laboratory evaluation. RESULTS: Three hundred and forty-four (54%) patients had a positive result. The most common type of response was mixed type (46%) followed by vasodepressor (39%) and cardioinhibitory (15%) types. Age, gender, presence of structural heart disease, baseline heart rhythm, and the presenting symptom before the test failed to predict a positive response to HUTT, but among patients with a positive response to the test, age (OR: 1.54, CI = 1.04-2.47, P = 0.016) and presyncope (OR: 2.16, CI = 1.2-3.85, P = 0.008) as the presenting symptom predicted a vasodepressor type of response. The age (OR: 1.58, CI = 1.29-3.94, P = 0.01) and presyncope (OR: 4.6, CI = 1.74-12.24, P = 0.001) were also predictors for test positivity in the active stage. CONCLUSIONS: There is an age-related gradient in hemodynamic response during neurocardiogenic syncope. The elderly patients more commonly had a vasodepressor and late response, in the active stage, but young subjects more commonly experienced an earlier and cardioinhibitory or mixed responses in the passive stage.