直立倾斜试验阳性反应发生时间的影响因素研究

目的探讨性别、年龄、基础心率、基础收缩压及基础舒张压对直立倾斜试验阳性反应发生时间的影响。方法选择2007年1月~2017年4月因晕厥在泰达国际心血管病医院就诊且直立倾斜试验检查阳性患者761例,分为基础试验阳性者141例与激发试验阳性者620例,分析2种试验的阳性反应发生时间与性别、年龄等因素的相关性。结果在基础试验中,与年龄≤30岁患者相比,年龄≥60岁患者阳性反应发生时间明显延长[(26.48±7.70)min vs(19.50±9.66)min,P0.05];与男性比较,女性阳性反应时间明显延长,差异有统计学意义[(25.12±9.94)min vs(21.32±9.54)min,P=0.023];男性患者阳性反应发生时间随年龄增大呈逐渐延长的趋势,与年龄≤30岁、31~59岁男性患者相比,年龄≥60岁男性患者阳性反应发生时间明显延长,差异有统计学意义(P0.01);而随年龄的增长,女性患者阳性反应发生时间先延长后缩短,与年龄≤30岁、≥60岁女性患者比较,31~59岁女性患者阳性反应发生时间有所延长,但三者比较无统计学差异(P0.05)。在激发试验中,与女性比较,男性阳性反应发生时间明显延长,差异有统计学意义[7(5,10)min vs 6(5,9)min,P=0.007]。结论在基础试验阳性患者中,女性阳性反应发生时间较男性延迟,男性随着年龄的增长,阳性反应发生时间逐渐延迟。而在激发试验阳性患者中,仅发现男性患者出现阳性反应的时间比女性延迟,与其他因素无关。     

对拟诊血管迷走性晕厥患者进行直立倾斜试验的时程

目的 探讨直立倾斜试验的不同阶段诱导出阳性反应的合适时程.方法 回顾性分析因临床拟诊血管迷走性晕厥而进行直立倾斜试验的773例患者检查资料.直立倾斜试验分为30 min的倾斜位(70°)基础试验阶段和20 min的药物(硝酸甘油0.2 mg舌下含化)激发阶段.结果 直立倾斜试验阳性率为55.2%,其中43例(10.1%)患者阳性反应出现在基础试验阶段,384例(89.9%)出现在药物激发阶段.在基础试验阶段,阳性反应中2例(4.7%)发生在倾斜位7.5 min以后;随着时间延长,阳性反应比例逐渐增加,9例(20.9%)在22.5 min达到最高,之后逐渐下降;93%的阳性反应发生在倾斜位10～25 min内.在硝酸甘油激发阶段,阳性反应发生率在服药后迅速上升,35.7%在10 min达到最高,之后迅速下降;96.1%的阳性患者发生阳性反应在服药后的15 min内.结论 直立倾斜试验的倾斜位时间至少25 min,而药物激发阶段时间至少15 min,继续增加时间并不能明显提高阳性率.

Abstract：

Objective To investigate the time course of positive head-up tilt test (HUTT) for patients with suspected vasovagal syncope.Methods Consecutive patients referred to the syncope unit of our center for recurrent unexplained syncope were included. The HUTT consisted of a 30 minute passive basic phase and a 20 minute sublingual nitroglycerin provocation phase if syncope did not develop during the passive phase.Results Positive HUTT was observed in 427 out of 773 consecutive patients (55.2%) patients including 43 patients (10.1%) during the passive basic phase and 384 patients (89.9%) during the nitroglycerin provocation phase. During the basic phase, the positive Hutt developed at 7.5 minute (n=2) and peaked at 22.5 th minute (20.9%, n=9) and then decreased gradually. Most positive reactions (93.0%, n=40) occurred between the 10 and 25 minutes during the basic phase. During the nitroglycerin provocation phase, the percentage of positive reactions increased rapidly after sublingual nitroglycerin, peaked at the 10th minute (35.7%, n=137) and decreased thereafter. Most positive reactions (96.1%, n=369) occurred within the first 15 minutes of provocation phase.Conclusion The appropriate duration for HUTT test could be modified to a 25 minutes passive basic phase plus 15 minutes nitroglycerin provocation phase.     

两步法直立倾斜试验的适宜倾斜时程

目的探讨两步法直立倾斜试验出现阳性反应的适宜倾斜时程。方法采用两步法直立倾斜试验,即先对816例受检者施行基础直立倾斜试验(BHUTT),再对其阴性患者施行舌下含化硝酸甘油激发直立倾斜试验(NHUTT)。对上述阳性病例的倾斜时程资料进行回顾性分析。结果 BHUTT的阳性率为16.54%(135/816);其中,0～10 min时程阳性率1.35%;11～25 min时程阳性率13.24%;26～30 min时程阳性率1.96%;>30 min者为0。BHUTT阳性结果全部包含在0～30 min之间。对681例BHUTT阴性者作NHUTT检查,阳性率为45.96%(375/816),占BHUTT阴性者的55.07%(375/681);其中,0～10 min时程阳性率33.46%;11～20 min时程阳性率12.50%;NHUTT阳性结果全部包含在0～20 min之间。结论采用两步法直立倾斜试验,基础试验的适宜时程为30 min,硝酸甘油激发试验的适宜时程为20 min,继续增加倾斜时间并不能提高阳性率。     

基础直立倾斜试验与舌下含服硝酸甘油直立倾斜试验诊断血管迷走性晕厥的价值

目的:探讨基础直立倾斜试验(HUT)与舌下含服硝酸甘油直立倾斜试验(SNHUT)对血管迷走性晕厥(VVS)的诊断价值。方法:对我院2011年至2012年共61例不明原因晕厥,并高度怀疑VVS的患者(晕厥组)进行直立倾斜试验,。并以22例健康者作为健康对照组。结果:晕厥组61例患者中倾斜试验阳性57例,阳性率达到93.44%。其中HUT阳性16例(26.23%),SNHUT阳性41例(67.21%)。22例健康对照组也同样进行这两试验,其中HUT阳性1例(4.54%),SNHUT阳性3例(13.63%)。晕厥组SNHUT阳性率高于HUT的,但无显著差异(χ2=0.175,P=0.683)。结论:直立倾斜试验是目前诊断血管迷走性晕厥的一种无创,重复性强,容易被患者所接受的较好方法。配合舌下含服硝酸甘油直立倾斜试验可提高试验的阳性率。     

直立倾斜试验对原因不明晕厥患者诊断价值及美托洛尔疗效

本研究用自制的倾斜板，对２４例原因不明晕厥患者（排除心、脑和药物等因素），进行检查。２１例诱发出症状，其中８例在基础状态下（占全组２４例的３３．３％）；１３例在用异丙肾上腺素静脉滴注时（占全组的５４．２％）。阳性反应表现为３种类型：①心脏抑制型１例；②血管抑制型２例；③混合型１８例。阳性病例给予美托洛尔５０ｍｇ，每日２次，其中６例６天后行直立倾斜试验未诱发出症状。所以，直立倾斜试验对原因不明晕厥患者的诊断是一种有效的方法。美托洛尔可用来防治直立倾斜试验诱发的晕厥。     

直立倾斜试验阳性患者晕厥类型及其相关因素

目的分析直立倾斜试验阳性患者晕厥类型及相关因素。方法对151例接受住院治疗的不明原因晕厥患者行基础直立倾斜试验及硝酸甘油诱发试验,观察倾斜试验过程中临床表现与血流动力学变化并进行相关性分析。结果阳性反应80例（52.9%）,其中基础倾斜试验阳性14例（17.5%）,硝酸甘油激发66例（82.5%）;1型（混合型）45例（56.2%）,2A型（心脏抑制不伴有心脏停搏）18例（22.5%）,2B型（心脏抑制伴有心脏停搏）5例（6.0%）。3型（单纯血管减压）8例（10%）,另外,根据血流动力学变化特点分为3组,分别是典型、不典型血管迷走神经性晕厥、直立不能耐受。其中典型阳性34例、占总阳性的42.5%,不典型46例（57.5%）,直立不能耐受组13例,3组在年龄上有显著差异（P<0.01）。典型血管迷走神经性晕厥患者病史较长（平均10年）,自主神经反应不良6年,直立不能耐受1年,3组在晕厥病史上有显著性差异（P<0.01）。结论倾斜试验中年轻患者多为典型的血管迷走性晕厥,较易诱发。     

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。     

直立倾斜试验的复合型反应

目的 对同一次直立倾斜试验（Head-up Tilt Test, HUTT）中的合并不同血流动力学反应的复合型反应进行总结分析。方法 226例晕厥或头晕或走路不稳患者在安静环境空腹进行HUTT持续监测心电和血压,观察其血压、心率变化及症状。结果 226例进行HUTT的患者中血管迷走性反应（Vasovagal Response,VVR）阳性91例,体位性心动过速（Postural Tachycardia Syndrome, POTS）30例,直立性低血压（Orthostatic Hypotension, OH）67例。POTS合并VVR(P-CFR)23例,OH合并VVR(O-CFR)15例,单纯VVR(Only-VVR)53例。结论 直立倾斜试验存在不同类型血流动力学反应的复合型反应,需要对不同阶段HUTT细致观察。     

直立不耐受的诊疗进展

直立不耐受是由直立位引发的一系列症状组成的综合征, 患者表现为失去维持直立状态的能力。直立不耐受可分为直立性低血压、直立性心动过速综合征、血管迷走性晕厥。有学者认为直立性高血压亦属于此范畴。直立不耐受的最大危害在于引发跌倒, 造成躯体损伤和心理问题。现对直立不耐受的诊疗进展进行综述, 期望有助于提高临床诊断的规范性和治疗的有效性。     

直立倾斜试验阳性反应患者心律失常分析

目的探讨直立倾斜试验(HUTT)阳性反应患者心律失常发生的特点。方法对2000年9月至2005年7月在中南大学湘雅第二医院晕厥专科门诊就诊或住院的不明原因晕厥或接近晕厥患者进行HUTT检查(所有患者均签署知情同意书)。分析HUTT过程中心律失常发生情况。采用SPSS10.0统计软件进行统计学处理。结果127例HUTT阳性反应患者中122例(96.06%)患者出现心律失常。107例(84.25%)发生快速性心律失常,并在儿童及舌下含服硝酸甘油倾斜试验(SNHUT)中发生率高(P<0.01),无性别差异(P>0.05)。快速性心律失常以窦性心动过速(98.13%,105/107)多见,其中99例(94.29%)患者在心率达最快后5min内,平均(1.73±1.72)min发生阳性反应。58例(45.67%)患者发生缓慢性心律失常,窦性心动过缓多见(91.38%,53/58),常合并交界性逸搏心律、交界性逸搏和窦性停搏。10例窦性停搏患者平均停搏时间为(12.68±17.94)s。缓慢性心律失常患者基础心率偏慢,且在成人及基础直立倾斜试验(BHUT)过程中发生率高(P<0.05或P<0.01),而男女性别差异无显著性(P>0.05)。结论(1)HUTT过程中心率突然明显增快时应警惕阳性反应的发生。(2)缓慢性心律失常在成人及BHUT中发生率较高,常见类型有窦性心动过缓、窦性停搏、交界性逸搏心律、交界性逸搏等,发生缓慢性心律失常患者的基础心率偏慢。     

Beat-to-beat analysis of pressure wave morphology for pre-symptomatic detection of orthostatic intolerance during head-up tilt

OBJECTIVES: The aim of this study was to noninvasively define the hemodynamic profile characterizing the early response to tilting. BACKGROUND: The mechanisms causing orthostatic intolerance have not been fully elucidated. Usually, patients undergoing tilt test are studied in a time-consuming way. Moreover, the test can cause discomfort to the patient and even be potentially hazardous. METHODS: Nineteen orthostatic intolerant patients (OIP), compared with 22 healthy subjects (HS), performed head-up tilt test while their arterial pressure waveform was noninvasively recorded. We elaborated data using the Pressure Recording Analytical Method to obtain hemodynamic parameters, then analyzing the variables by discriminant analysis. RESULTS: Compared with HS, OIP showed lower stroke volume index (SVI) values even in baseline conditions associated with higher values of systemic vascular resistance (SVR) and heart rate (HR). From the third minute of the tilted position and until symptoms appeared, patients exhibited lower values of blood pressure (BP) and SVI and higher HR values but no difference in SVR. At termination, patients showed a further significant reduction in BP and SVI and a persistent increase in HR. CONCLUSIONS: This investigation underlines: 1) the possibility of beat-to-beat monitoring of hemodynamic changes during tilting; 2) the cardiovascular profile of OIP at rest, characterized by lower SVI and higher SVR and HR; 3) the maladaptive response to postural challenge of OIP mainly identifiable in impaired vascular regulation; and 4) the possibility of detecting parameters that enable prompt identification of the positive response to tiltingin these patients, thus guiding the duration of the test.     

Reproducibility of circulatory changes to head-up tilt in healthy elderly subjects

OBJECTIVE: to assess the reproducibility of the cardiovascular responses to head-up tilt including cardiac output, stroke volume and peripheral resistance, in healthy older subjects using non-invasive methods. PARTICIPANTS: twenty-five healthy community-dwelling volunteers with a mean age of 69+/-3 years. METHODS: the subjects underwent head-up tilt table testing on two occasions at an interval of 6 weeks. Pulse interval and blood pressure data were collected, on a beat-to-beat basis using a non-invasive monitor (Finapres, Ohmeda), during 70 degrees head-up tilt table testing and stored for analysis. ANALYSIS: the pulse interval and blood pressure data for the group were pooled and the relative changes in cardiac output, stroke volume and peripheral resistance were calculated using pulse contour analysis. RESULTS:the systolic blood pressure, pulse interval, cardiac output and stroke volume fell immediately after tilt with a rise in peripheral resistance. These responses were similar, though the baseline systolic blood pressure levels were lower at the second visit (P=0.06). CONCLUSION: these non-invasively assessed cardiovascular responses to head-up tilt in healthy older subjects show little variation between visits. The reproducibility of the responses in subjects with syncope and autonomic failure warrants further investigation.     

Isoproterenol test and head-up tilt test for diagnosis of vasovagal syncope in elderly patients

The elderly can be affected by vasovagal syncope, but they often do not have preceding symptoms. The head-up tilt test (HTT) is successfully used in half of the patients in which the diagnosis is difficult. In young people the association with the isoproterenol test improves the sensitivity of the HTT. In the elderly the effect of such an association is still debated, therefore, the present study was aimed at evaluating the usefulness of the association between the two tests in old subjects to unmask the vasovagal nature of some syncopes of unknown origin. Twenty-four patients with negative HTT (18 males and 6 females; mean age 65 years) 10 with and 14 without organic heart disease were studied. The test protocol consisted of a continuous intravenous infusion of isoproterenol in successive stages starting from a dosage of 1 gamma/min for 5 min in supine position and then for 10 min in passive upright position at 80 (1st stage) up to maximum of 5 gamma/min (5th stage). The results obtained were: 12 patients (50%) had a positive test (reproduction of syncope) with a vasodepressor response in 6 of them and a mixed response in 6 patients. The mean time to syncope was during the 4th min of the 4th stage of treatment. The heart rate increase was 36% between the initial and peak values achieved during the test in patients with a positive test, and 10.5% in patients with negative test (p < 0.05). These results indicate that the isoproterenol test seems to increase the sensitivity of HTT in elderly patients with syncope of unknown origin.     

Cerebral blood flow during supine rest and the first minute of head-up tilt in patients with orthostatic intolerance.

AIM: To assess the cerebral blood flow velocity during the first minute of head-up tilt in patients with postural tachycardia syndrome (POTS) or neurally-mediated reflex syncope compared with patients with dizziness. METHODS: We evaluated 120 patients selected from 470 patients who underwent head-up tilt testing: 40 with POTS, 40 with typical neurally-mediated reflex syncope and 40 who complained of dizziness with no history of loss of consciousness and a negative head-up tilt test (with and without isosorbide). Transcranial Doppler sonography of the middle cerebral artery, heart rate and brachial blood pressure were recorded during a 70 degrees head-up tilt test. RESULTS: During both baseline in supine position and the first minute of upright tilt, patients with postural tachycardia syndrome showed higher heart rate and cerebral blood flow velocity than patients with dizziness and patients with neurally-mediated reflex syncope (P < 0.05, ANOVA), but no significant difference was observed on the Gosling's pulsatility index. CONCLUSION: Patients with POTS have an autonomic dysfunction that is not triggered by upright posture but is accentuated by it.     

直立倾斜试验对老年不明原因晕厥患者的诊断价值

目的：探讨直立倾斜试验对老年不明原因晕厥患者的诊断价值。方法：对140例老年不明原因晕厥患者在安静环境下进行直立倾斜试验．持续监测心率和血压变化。结果：140例老年不明原因晕厥患者在直立倾斜试验中,阳性反应80例（男43例．女37例）。其中血管抑制型39例（男21例,女18例）,心脏抑制剂9例（男4例,女5例）,混合刑32例（男18例,女14例）。血管抑制型患者晕厥时与晕厥前相比,血压从（122±14／69±15）mm—Hg下降到（82±15／45±10）mmHg（P〈0．01）;心脏抑制剂患者晕厥前心率为（95±17）次／min．晕厥时下降至（51土8）次／min（P〈0．01）;混合型患者晕厥前心率为（110±21）次／min。晕厥时下降至（63±21）次／min（P〈0．01）,血压从（115±18／65±18）mmHg下降到（83±19／46±10）mmHg（P〈0．01）。结论：直立倾斜试验是诊断老年不明原因晕厥的有效方法,血管抑制型是其最常见的类型．其阳性率和血流动力学模式分布在性别上无显著性差异。     

Reduced plasma renin activity in elderly subjects in response to vasovagal hypotension and head-up tilt

The sympathoadrenal and renin-angiotensin systems play an important role in the cardiovascular responses induced by head-up tilt. In young people, hypotension and postural changes induced by tilt produce significant increases in plasma renin activity. The response of plasma renin activity to prolonged tilt and subsequent vasovagal hypotension has not been assessed in the elderly. Seventeen elderly subjects (10 with carotid sinus syndrome and seven age-matched controls) were studied during 45 minutes of recumbency and 120 minutes of head-up tilt to 40 degrees. Intra-arterial systolic blood pressure and heart rate were monitored continuously and plasma renin activity was measured at frequent intervals. Ten subjects developed vasovagal syncope during tilt (at 32 +/- 18 min). Systolic blood pressure and heart rate fell by 70 +/- 20 mmHg and 20 +/- 7 beats . min-1 (P less than 0.001 and P less than 0.01, respectively). Plasma renin activity did not change in syncopal subjects and remained unchanged up to 60 min after syncope. In seven subjects who completed 120 min of tilt without symptoms, heart rate rose during tilt but plasma renin activity remained unchanged. Plasma renin activity is not influenced by marked hypotension or prolonged head-up tilt in the elderly.     

Predicting outcomes on head-up tilt based on orthostatic hypotension patterns

OBJECTIVE: To assess the frequency of different orthostatic hypotension (OH) patterns in patients having supine hypertension with OH ('SHOH') versus patients with OH and normal supine blood pressure ('OH alone'); and to relate OH patterns with outcomes on head-up tilt. METHODS: Consecutive patients with nonspecific dizziness were studied with a 10-min supine, 30-min head-up tilt test. Supine hypertension was diagnosed when supine systolic blood pressure (SBP) was at least 140 mmHg and/or supine diastolic blood pressure was at least 90 mmHg. OH was defined as SBP reduction of at least 20 mmHg within 3 min of tilt. OH patterns were identified corresponding to SBP time-curves during the initial 5 min of tilt: progressive, sustained and transient patterns. RESULTS: Among 400 patients tested, 31 had 'SHOH' and 39 had 'OH alone'. Frequencies of OH patterns were similar in both groups. The progressive OH pattern predicted symptomatic hypotension, leading to early tilt termination in all 'SHOH' and 88% of 'OH alone' patients. In comparison, tilt was early terminated in 33-48% of patients with sustained OH, transient OH and without OH. Early tilt termination was unrelated to age, gender, magnitude of supine SBP, pulse pressure and nadir SBP within 5 min tilt. CONCLUSIONS: Five minutes of postural challenge permitted assessing OH patterns. Outcome on protracted tilt was related to OH patterns, the worse outcome being likened to progressive OH, both in patients with 'SHOH' and in patients with 'OH alone'. Future studies will show whether OH patterns may serve as guidance for blood pressure therapy in selected patients.     

Reproducibility of head-up tilt test in patients with syncope

As the head-up tilt test (HUT) is employed to verify the efficacy of undertaking a treatment, we prospectively evaluated the reproducibility of positive and negative results, as well as that of the response type in 64 consecutive patients (mean age 34.6 ± 22.9 years) with syncope of unknown cause. Two HUTs (60 min, 75° ), separated by an interval of 9.77 ± 8.21 days, were performed on each patient. Positive responses were reproduced in the second HUT in 54.5% of the patients. A greater reproducibility (84.3%) was observed for negative responses. Of the 31 patients with a negative first test, 5 had a positive response during the second HUT. Using a multivariate analysis, no clinical variable correlated with the reproducibility of positive or negative results. Likewise, neither arterial pressure nor heart rate observed during the test were correlated with reproducibility. Of 18 patients who reproduced positive responses, 12 (66.6%) did so with the same response modality. In three patients with documented monomorphic sustained ventricular tachycardia, which was hemodynamically well tolerated, and in one patient with temporal spike wave activity in the electroencephalogram, HUT was also positive. It was concluded that the low reproducibility of HUT limits its usefulness as a tool for evaluating treatment efficacy. The variability of the type of response suggests a common mechanism leading to cardioinhibitory and vasodepressor reactions. A positive result in only the second study shows the rationale of performing two tests when the first one is negative.     

直立倾斜试验阳性反应出现后的心律失常特征

目的 探讨直立倾斜试验(HUTT)阳性反应出现后患者心律失常发生的特征.方法 分析2001年3月至2009年8月在基础直立倾斜试验(BHUT)或舌下含化硝酸甘油倾斜试验(SNHUT)阳性反应出现后发生心律失常的169例患者资料,男性57例,女性112例,年龄6～65(23.1±14.8)岁,儿童(<18岁)86例,成人(≥18岁)83例.结果 心律失常发生在BHUT和SNHUT阳性反应后的患者分别为75例(44.38%)、94例(55.62%).常见类型为窦性心动过缓(143例,84.62%)、交界性逸搏心律(55例,32.54%)、窦性停搏(26例,15.38%),其中窦性心动过缓在成人更多见(P<0.01),窦性停搏和交界性逸搏心律的发生无年龄、性别和试验方式差别;心律失常与晕厥或接近晕厥的临床表现几乎同时出现者为77例(45.56%)、滞后出现者92例(54.44%),并且前者多发生在BHUT中,后者多发生在SNHUT中(P<0.05);心律失常与血压下降几乎同时出现者为84例(53.50%),滞后出现者73例(46.50%),且前者多发生在BHUT中,后者多发生在SNHUT中(P<0.01).结论 (1)HUTT阳性反应发生后常见心律失常为窦性心动过缓、交界性逸搏心律和窦性停搏,窦性停搏的发生无年龄、性别和试验方式的差别,试验操作中需提高警惕;(2)BHUT中,心律失常多与晕厥或接近晕厥的表现、血压的下降同时发生;SNHUT中,心律失常多发生于晕厥或接近晕厥的表现和血压下降之后,可能与硝酸甘油药理作用有关.