直立倾斜试验诊断血管迷走性晕厥的监护及护理

直立倾斜试验诊断血管迷走性晕厥的监护及护理大连医科大学附属第一医院（１１６０１１）郝艳香张直立倾斜试验（ＨＵＴ）国外起始于６０年代末、７０年代初。国内自１９９２年始使用静点异丙肾上腺素诱发晕厥，主要探讨血管迷走性晕厥的发病机制。诊断及影响倾斜试验的...     

舌下含服硝酸甘油和静脉滴异丙肾上腺素倾斜试验的对比研究

目的：评价舌下含服硝酸甘油倾斜试验（GTTT）的安全性和对血管迷走性晕厥（VVS）的诊断价值。方法：67例血管迷走性晕厥患者及20例无晕厥史的健康人行基础试验（BTTT）,BTTT阴性者连续2天随机作异丙肾上腺素倾斜试验（ITTT）和GTTT。结果晕厥组BTTT阳性20例,阴性反应的47例中GTTT阳性30例,ITTT阳性31例,对照组BTTT、GTTT和ITTT分别有1、1和2例阳性,ITTT和GTTT的敏感性和特异性分别为68．9％对63．8％和89．4％对94．7％。结论GTTT中诊断VVS安全而有效的方法,其敏感性和特异性与ITTT相似,患者有较好的耐受性。     

舌下含化硝酸甘油倾斜试验诊断血管迷走性晕厥的可行性

目的：评价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，并对其诱发血管迷走性晕厥的原因进行探讨。方法：选择2002—10／2004-01邢台市人民医院心内科门诊及住院部就诊的不明原因的晕厥患者23例为晕厥组，男9例，女14例，平均年龄（31&;#177;14）岁。同期选择本院无晕厥或晕厥前兆发作的健康人13名为对照组。男5名，女8名，平均年龄（33~11）岁。纳入对象对本实验均知情同意。①倾斜试验方法：所有受试者首先进行基础倾斜试验，阴性者平卧休息10min后随机接受舌下含化硝酸甘油倾斜试验或静脉滴注异丙肾上腺素倾斜试验，其中舌下含化硝酸甘油倾斜试验及静脉滴注异丙肾上腺素倾斜试验间隔时间为1周，进行交叉给药试验。②血浆中的肾上腺素和去甲肾上腺素水平测定：在舌下含化硝酸甘油倾斜试验中，分别于平卧位、晕厥发作或终止试验时各取静脉血3mL，分别取血浆采用高效液相色谱和电化学检测法测定血浆中的肾上腺素和去甲肾上腺素水平。③统计学分析：计量资料比较用t检验，计数资料用X^2检验。阳性反应与性别、年龄．晕厥次数、病程使用二项分类Logistic回归（前进法）分析。结果：①敏感性和特异性：基础倾斜试验中，晕厥组23例患者中有3例发生晕厥，在舌下含化硝酸甘油倾斜试验中，晕厥组阳性者11例，敏感性60．9％，对照组有2名用药后出现阳性反应，特异性为84．6％。在静脉滴注异丙肾上腺素倾斜试验中，晕厥组10例患者发生阳性反应，敏感性56．5％。对照组阳性者1名，特异性为92．3％。以上两组试验敏感性、特异性差异不明显（P〉0．05）。②出现阳性反应时间：在舌下含化硝酸甘油倾斜试验为用药后（6．99&;#177;3．30）min，在静脉滴注异丙肾上腺素倾斜试验中为用药后（6．47&;#177;2．51）min，两组试验结果差异不明显（P〉0．05）。⑧二项分类Logistic回归（前进法）得出回归方程分析发现患者年龄越大，阳性反应越低（OR=0．873，P=0．016），即年龄为保护因素，年龄每增加1岁，晕厥风险降低12．7％。（少血浆儿茶酚胺水平测定结果：在舌下含化硝酸甘油倾斜试验中，与平卧位相比，阳性组患者晕厥时血浆肾上腺素水平明显高于阴性组和对照组（P〈0．05），而血浆去甲肾上腺素水平的增高，阳性组、阴性组和对照组差异不明显（P〉0．05）。结论：①舌下含化硝酸甘油倾斜试验倾斜后观察20min，既节约时间又不影响其敏感度和特异性。②年龄越大，阳性反应率越低。③采用0．3mg硝酸甘油做倾斜试验，其敏感性、特异性良好，与异丙肾上腺素相近，副作用少。④血浆肾上腺素水平增高可能是硝酸甘油倾斜试验诱发血管迷走性晕厥的原因。     

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。     

舌下含服硝酸甘油和静脉滴注异丙肾上腺素倾斜试验的对比研究

目的评价舌下含服硝酸甘油倾斜试验(GTTT)的安全性和对血管迷走性晕厥(VVS)的诊断价值.方法 67例血管迷走性晕厥患者及20例无晕厥史的健康人行基础倾斜试验(BTTT),BTTT阴性者连续2天随机作异丙肾上腺素倾斜试验(ITTT)和GTTT.结果晕厥组BTTT阳性20例,阴性反应的47例中GTTT阳性30例,ITTT阳性31例;对照组BTTT、GTTT和ITTT分别有1、1和2例阳性,ITTT和GTTT的敏感性和特异性分别为68.9%对63.8%和89.4%对94.7%.结论 GTTT是诊断VVS安全而有效的方法,其敏感性和特异性与ITTT相似,患者有较好的耐受性.     

倾斜试验致低血压性休克8例分析

近年来 ,倾斜试验 (ＨＵＴ )逐渐成为诊断血管迷走性晕厥(ＶＶＳ)的重要手段。ＨＵＴ是基于正常人突然改变体位导致静脉容积增加 ,心排出量减少 ,主动脉弓及颈动脉窦压力感受器张力减弱 ,迷走神经传入张力消失 ,交感神经传出信号增加 ,通过心率加快代偿 ,以增加心排出量[1] 。本组 8例不明原因的晕厥的病人在接受多阶段异丙肾上腺素倾斜试验 (ＭＩＴＴＴ)过程中 ,静脉输注异丙肾上腺素时出现心率减慢、血压下降、面色苍白、出冷汗、烦躁不安、意识淡漠等休克表现。现报告如下 :1　临床资料与方法1.1　一般资料　 8例不明原因的晕厥病人均来…     

舌下含化硝酸甘油倾斜试验诊断血管迷走性晕厥的可行性

目的:评价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,并对其诱发血管迷走性晕厥的原因进行探讨。方法:选择2002-10/2004-01邢台市人民医院心内科门诊及住院部就诊的不明原因的晕厥患者23例为晕厥组,男9例,女14例,平均年龄(31±14)岁。同期选择本院无晕厥或晕厥前兆发作的健康人13名为对照组,男5名,女8名,平均年龄(33±11)岁。纳入对象对本实验均知情同意。①倾斜试验方法:所有受试者首先进行基础倾斜试验,阴性者平卧休息10min后随机接受舌下含化硝酸甘油倾斜试验或静脉滴注异丙肾上腺素倾斜试验,其中舌下含化硝酸甘油倾斜试验及静脉滴注异丙肾上腺素倾斜试验间隔时间为1周,进行交叉给药试验。②血浆中的肾上腺素和去甲肾上腺素水平测定:在舌下含化硝酸甘油倾斜试验中,分别于平卧位、晕厥发作或终止试验时各取静脉血3mL,分别取血浆采用高效液相色谱和电化学检测法测定血浆中的肾上腺素和去甲肾上腺素水平。③统计学分析:计量资料比较用t检验,计数资料用χ2检验。阳性反应与性别、年龄、晕厥次数、病程使用二项分类Logistic回归(前进法)分析。结果:①敏感性和特异性:基础倾斜试验中,晕厥组23例患者中有3例发生晕厥,在舌下含化硝酸甘油倾斜试验中,晕厥组阳性者11例,敏感性60.9%,对照组有2名用药后出现阳性反应,特异性为84.6%。在静脉滴注异丙肾上腺素倾斜试验中,晕厥组10例患者发生阳性反应,敏感性56.5%。对照组阳性者1名,特异性为92.3%。以上两组试验敏感性、特异性差异不明显(P>0.05)。②出现阳性反应时间:在舌下含化硝酸甘油倾斜试验为用药后(6.99±3.30)min,在静脉滴注异丙肾上腺素倾斜试验中为用药后(6.47±2.51)min,两组试验结果差异不明显(P>0.05)。③二项分类Logistic回归(前进法)得出回归方程分析发现患者年龄越大,阳性反应越低(OR=0.873,P=0.016),即年龄为保护因素,年龄每增加1岁,晕厥风险降低12.7%。④血浆儿茶酚胺水平测定结果:在舌下含化硝酸甘油倾斜试验中,与平卧位相比,阳性组患者晕厥时血浆肾上腺素水平明显高于阴性组和对照组(P<0.05),而血浆去甲肾上腺素水平的增高,阳性组、阴性组和对照组差异不明显(P>0.05)。结论:①舌下含化硝酸甘油倾斜试验倾斜后观察20min,既节约时间又不影响其敏感度和特异性。②年龄越大,阳性反应率越低。③采用0.3mg硝酸甘油做倾斜试验,其敏感性、特异性良好,与异丙肾上腺素相近,副作用少。④血浆肾上腺素水平增高可能是硝酸甘油倾斜试验诱发血管迷走性晕厥的原因。     

舌含硝酸甘油直立倾斜试验对血管迷走性晕厥诊断价值探讨(附97例分析)

直立倾斜试验(Head up tilt testing，Hut)对血管迷走性晕厥(Vasovagal syncope，VVS)的诊断价值基本得到肯定。但基础的直立倾斜试验诱发率偏低30％～40％，采用静滴异丙肾上腺素诱发VVS，国内外均有报道，由于异丙肾上腺素所引起的心绞痛，室性心律失常等。我院采用舌下含化酸甘油代替静脉滴注异丙肾上腺素诱发VVS，其敏感性为77％，特异性为93％，现报告如下：     

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。     

直立倾斜试验在血管性晕厥中的诊断价值

晕厥在临床上是比较常见的一种急症。其预后随病因不同而相关悬殊。属心源性者随时有摔死可能，应及时紧急处理，而多数晕厥发作并非心源性，其预后相对较好，应及时判明原因解除戒备，二者处理原因不大相同，按以往常规方式诊断，仍有50％的患者不能明确。直立倾斜试验（HUT）国外起始于60年代末，对诊断及鉴别诊断血管性晕厥有重要价值[1]，是目前国内外所公认的唯一检查方法。本文采用特异性及敏感性较高的静滴异丙肾上腺素重复试验，并观察两者在患者组及正常组中的心率、收缩压、舒张压变化，以探讨有关血管过走性晕厥的诊治问题。1…     

Sensitivity and Specificity of the Tilt Table Test in Young Patients with Unexplained Syncope

The usefulness of the head-up tilt testing (HUT) has heen previously addressed in diagnosing vasovagal neuroregulatory syncope in the teenage population. However, data concerning sensitivity and specificity is deficient due to the lack of control groups. We compared the response to HUT in young patients referred because of syncope or near syncope (n = 44, mean age 16 ± 3 years SD) to healthy young volunteers with a normal physical examination and no previous history of syncope (n = 18, mean age 16 ± 2 years) and io determine the sensitivity and specificity of HUT. The graded tilt protocol was performed at 15°, 30°, and 45° (each for 2 min), and then 60° for 20 minutes. Cuff blood pressure was measured every minute and lead IIECG was continuously monitored. Results; 25 of the 44 patients (57%) developed a vasovagaJ response or became symptomatic after 13.8 ± 5.7 minutes of HUT. Three of the 18 volunteers (17%) had a vasovagal response and became symptomatic after 9 ± 3 minutes of HUT. There was no statistical difference among the four groups (with and without tilt induced vasovagal response) in terms of age and baseline hemodynamic data. The sensitivity of 20 minutes HUT was 57% and its specificity was 83%. The presyncopal hemodynamic response in patients with history of syncope that was characterized by a significant decrease in systolic blood pressure and lack of increase of diastolic blood pressure as compared with baseline and with other groups. Gonclusions: 20 minutes at 60° HUT has a high specificity for the diagnosis of vasovagal syncope. Its limited sensitivity is counterbalanced by the advantage of limiting the incidence of false-positive results in patients without the vasovagal syndrome.     

Tolerance to Lower Body Negative Pressure Exposure: Comparison Between Patients with Neurocardiogenic Syncope and Controls

Lower body negative pressure exposure (LBNPE) produces hemodynamic modifications similar to those produced by head-up tilt test (HUT). Patients with vasovagal syncope are more susceptible to HUT than healthy persons. The supine position during LBNPE would facilitate the simultaneous performance of complementary methods. The aim of this study was to compare tolerance to LBNPE between a group of patients with vasovagal syncope and a group of healthy volunteers. Eleven patients with vasovagal syncope and positive HUT and 13 healthy volunteers without prior history of syncope and negative HUT were included. The following protocol was used: −10 mmHg, 1 minute; −20 mmHg, 1 minute; −30 mmHg, 3 minutes, and −40, −50, −60, and −70 mmHg, 5 minutes for each stage. Tolerance was expressed as: maximum tolerated negative pressure (Max NP), maximum tolerated time (Max T), and Σ P × T, where P = pressure and T = time. Syncope or presyncope during the test was considered positive LBNPE. LBNPE was positive at −50 or −60 mmHg in 8 of 11 patients (73%). One healthy volunteer had presyncope after 5 minutes at −70 mmHg. Tolerance, as expressed by any of the three parameters, was significantly higher for the healthy volunteers (Max NP: −59.1 ± 7.9 vs −70, P < 0.01; Max T: 19.1 ± 4.2 vs 24.4 ± 0.3, P < 0.01; Σ P × T: 836.3 ± 269.5 vs 1214.6 ± 18, P < 0.01). We conclude that patients with neurocardiogenic syncope have a significantly lower tolerance to LBNPE than subjects with no previous history of syncope.     

Is Absolute Hypovolemia a Risk Factor for Vasovagal Response to Head-Up Tilt?

To test the hypothesis that hypovolemia is associated with an increased incidence of vasovagal syncope during head-up tilt (HUT) 45 patients with history of syncope or presyncope were studied. Blood volume (radio-iodinated serum albumin) was determined, then subjects underwent a graded HUT (from 15°–60° HUT) with cuff blood pressure and ECG monitoring. All patients were kept on their own medications during evaluation. Thirty patients (12 male, 18 female, mean age 50 ± 19 [SD] years) had hypovolemia, defined as blood volume < 90% of lab normal for corresponding sex, while 15 patients (7 male, 8 female, mean age 52 ± 21 years) were normovolemic with blood volume ranging from 91%-110% of sex-matched normal subjects. The normovolemic patients served as controls. During HUT, a vasovagal response was elicited in 5 of the 30 hypovolemics and in 4 of the 15 normovoiemic (16.7% and 26.7%, respectively, P = NS). In those who developed vasovagal response, the changes of heart rate and blood pressure during HUT were not significantly different between hypovolemics and normovolemics, neither at the endpoint (vasovagal response) nor immediately before the development of the vasovagal response. In patienis with nonvasovagal events, four types of hemodynamic responses to tilt were observed; normal blood pressure response associated with normal heart rate increase, normal blood pressure response in association with accentuated increase in heart rate, orthostatic hypotension with normal acceleration of heart rate, and orthostatic hypotension with accelerated increase in heart rate. The percent distribution of these responses were 44%, 20%. 0%, and 36% in the 25 nonvasovagal hypovoiemics versus 73%, 0%, 18%, and 9% in the 11 nonvasovagal normovolemics. The results demonstrate that supine total blood volume does not predict the occurrence of vasovagal response to HUT. However, accentuated orthostatic tachycardia was more prevalent in hypovolemics as compared to normovolemics with nonvasovagal response to tilt.     

Neurohormonal Profile Before and After β-Blockade in Patients with Neurocardiogenic Syncope

Our objective was to evaluate the effects of beta-blockers on the neurohormonal profile, particularly vasopressin (VP) release, in vasovagal syncope and to gain further insight on the pathophysiology of this syndrome. Patients (< or =75 years) with no cardiovascular, neurological disorders, or contraindications to the use of isoproterenol or beta-blockers and being explored for unexplained syncope were included. An 80 degrees HUT was performed under identical conditions. After a 25-min period of passive tilt, isoproterenol was infused at a rate of 1-5 microg/mn if required. Two groups matched for age and sex were considered: a HUT-positive and a HUT-negative group. The HUT-positive group was then given beta-blockers, subsequently reassessed, and divided into two subgroups: alpha beta-blocker nonresponder group and a beta-blocker responder group. Blood samples for assays of norepinephrine (NE), epinephrine (E), and VP were taken at baseline and the end of the procedure. In all, 44 subjects entered the study, 22 in each group. The HUT-positive group exhibited an obvious lesser increase in plasma NE and a clear-cut rise in plasma E and VP compared to the HUT-negative group (P < 0.05). Even though no patient in the HUT-positive group reported recurrent symptoms under treatment, the second HUT could distinguish two subgroups: a beta-blocker nonresponder group (n = 12) whose HUT remained positive and a beta-blocker responder group (n = 10) whose HUT was normalized. The time course of plasma E and VP during the second HUT was similar to that for the HUT-positive and HUT-negative groups. In conclusion, the efficacy of beta-blockers is associated not only with a reduction of the sympathoadrenal stimulation seen in vasovagal syncope but also with a lower release of VP suggesting that low-pressure baroreceptors might be involved in VP release.     

Reproducibility of Head Upright Tilt Table Test Results in Patients with Syncope

Head upright tilt table testing is a promising technique for the evaluation and management of vasovagal (neuroregulatory) syncope. In order to determine the day-to-day reproducibility of results using this technique we performed head upright tilt table testing (with or without graded isoproterenol infusion) in 21 patients (12 males, 9 females, mean age 34 ± 19.1 years). During the first tilt study a total of 14 patients experienced syncope (six during baseline tilt, mean tilt time 15.8 ± 7 minutes, eight following tilt with graded isoproterenol infusion, mean tilt time 17.7 ± 9 minutes) while seven were negative. During the second tilt study (performed 3–7 days following the first study) the results of the first study were duplicated in 19 patients (90%) (six during baseline tilt, mean time 17.5 ± 8 minutes, eight following graded isoproterenol infusion, mean time 15.9 ± 7 minutes), however the level of provocation required to provoke syncope differed from that needed in the initial test in five patients (24%). We conclude that the results of head upright tilt table testing with graded isoproterenol infusions can be duplicated in 90% of patients, although some day-to-day variability exists in the degree of provocation necessary to elicit a positive response.     

Predictors of Positive Head-Up Tilt Test in Patients with Suspected Neurocardiogenic Syncope or Presyncope

OH, J.H., et al .: Predictors of Positive Head-Up Tilt Test in Patients with Suspected Neurocardiogenic Syncope or Presyncope. Neurocardiogenic syncope is the most common cause of syncope in patients who present in outpatient clinics. Head-up tilt test (HUT) has been widely used to diagnose neurocardiogenic syncope. However, the HUT does not always produce a positive response in patients with suspected neurocardiogenic syncope. The aim of the present study was to assess the clinical history and characteristics of patients with suspected neurocardiogenic syncope or presyncope who undertook HUT, and to identify prognostic factors of a positive HUT response. During the first phase of HUT, patients were tilted to a 70-degree angle for 30 minutes. If the first phase produced a negative response, the second phase was subsequently performed involving intravenous isoproterenol administration. Of 711 patients, 423 (59.5%) patients showed a positive HUT response. In contrast to previous studies, this study showed that the vasodepressive type (76.6%) was the most common pattern of positive response, and that the rate of positive response during the first phase was low (7.1%). By multivariate analysis, the occurrence of junctional rhythm was found to be a predictor of an impending positive response in HUT   (P < 0.001)   . The shorter time interval between the last episode and HUT was also a predictor of positive response   (P = 0.0015)   . Younger age   (P = 0.0003)   and a history of physical injury during a syncopal episode   (P = 0.019)   were found to be associated with a positive response in the first phase of HUT. (PACE 2003; 26[Pt. I]:593–598)     

Holter Monitoring vs Tilt Testing in the Investigation of Suspected Vasovagal Syncope

The aim of this study was to compare the diagnostic yield of 48-hour Holter monitoring with head-up tilt (HUT) test in patients presenting with blackouts suggestive of vasovagal syncope. One hundred and eighteen consecutive patients, 68 women, aged (mean [SD])   50 ± 20  years   (range 16–88 years), underwent 48-hour Holter monitoring and 60° HUT test within 3 months. Endpoints were symptom-ECG correlation during Holter monitoring and positive HUT test. Syncope occurred in 3 (3%) patients during Holter monitoring, the rhythm being sinus tachycardia in all. Presyncope was reported in 22 (19%), the rhythm being sinus tachycardia in 6, persistent atrial fibrillation in 2, and normal sinus rhythm in the remainder. Asymptomatic arrhythmias were recorded in 103 (87%) patients. Positive HUT tests occurred in 39 (33%), the pattern being mixed (VASIS type 1) in 14 (36%), cardioinhibitory (VASIS type 2) in 3 (8%), and vasodepressor (VASIS type 3) in 22 (56%). Change in patient management occurred in 3 (3%) patients following Holter monitoring and 39 (33%) patients following HUT test. Holter monitoring produces a low yield of clinically useful information in the investigation of suspected vasovagal syncope. An HUT test should be considered the primary investigation of choice in such patients. (PACE 2003; 26[Pt. I]:1523–1527)     

The Use of Head-Upright Tilt Table Testing in the Evaluation and Management of Syncope in Children and Adolescents

Recurrent syncope in an otherwise healthy child or adolescent is a common anxiety provoking disorder. Vasovagally mediated hypotension and bradycardia are believed common, yet difficult to diagnose, causes of syncope in this age group. Upright tilt table testing has been suggested as a potential method to test for vasovagal episodes. This study evaluated the utility of this technique in the evaluation and management of recurrent syncope in children and adolescents. Thirty patients with recurrent unexplained syncope were evaluated by use of an upright tilt table test for 30 minutes, with or without an infusion of isoproterenol (1 to 3 micrograms/min given intravenously), in an attempt to produce hypotension, bradycardia, or both. There were 15 males and 15 females, mean age 14 +/- 6 years. Each of the tilt positive patients received therapy with either fluorohydrocortisone, beta blockers, or transdermal scopolamine. Syncope occurred in six patients (20%) during the base line tilt and in 15 patients (50%) during isoproterenol infusion (total positives 70%). All initially positive patients were rendered tilt negative by therapy. Over a mean follow-up period of 20 months, no further episodes have occurred. We conclude that tilt table testing is a useful and effective test in the evaluation of unexplained syncope in childhood.     

Head-Up Tilt Test in Patients with High Pretest Likelihood of Neurally Mediated Syncope: An Approximation to the "Real Sensitivity" of this Testing

This study was designed to examine the "true sensitivity" of a specific head-up tilt (HUT) testing protocol using clinical findings. The HUT protocol used 45 minutes at 60 degrees for the baseline portion and intermittent boluses of 2, 4, and 6 micrograms of isoproterenol in the second phase. Eighty-eight patients (40 men and 48 women; mean age of 33.8 +/- 16 years) with recurrent syncope and high pretest likelihood of neurally mediated syncope were included. The following were considerated as high pretest likelihood criteria: (1) at least two syncopal episodes; (2) no structural heart disease and normal baseline ECG; (3) age < 65 years; (4) a typical history of neurally mediated syncope, triggering factors plus premonitory signs; and (5) short duration of symptoms and fast recovery without neurological sequelae. Fifty-four patients (61%) had a positive tilt test (34/88 baseline [39%] and 20/50 with isoproterenol [40%]). The shorter time interval between the last syncopal episode and baseline HUT test was the only predictor for a positive response (P < 0.003). Conversely, this time interval was not predictor of positive responses during isoproterenol-tilt testing. In conclusion: (1) we claim a "sensitivity" for this combined protocol of 61%; and (2) our results indicate that patients with syncope of unknown origin must be tilted nearest as possible to the last syncope to increase the positive responses of HUT test.     

An association between anxiety and neurocardiogenic syncope during head-up tilt table testing

To study the association between anxiety and neurocardiogenic syncope as determined by head-up tilt table testing (HUT) in men and women with presyncope or syncope, patients with unexplained syncope or presyncope undergoing HUT were asked to complete the Burns Anxiety Inventory (BAI), a validated inventory of 33 questions with responses graded from 0 to 3. HUT consisted of a 30-minute tilt to 60 degrees, which if negative, was repeated with an isoproterenol infusion. A positive HUT was defined as symptomatic hypotension and/or bradycardia. Of the 66 patients who completed the BAI and underwent HUT, 33 were men and 33 were women. The mean age was 57 +/- 18 years (17-91 years). Patients with a positive HUT had a higher BAI score than those with a negative HUT (22 +/- 12 vs 14 +/- 13, P = 0.017). This association was stronger in women with a BAI score of 24 +/- 11 in those with a positive HUT versus 13 +/- 8 in those with a negative HUT (P = 0.005). In contrast, the mean BAI score for men with a positive HUT was 19 +/- 13, as compared to 15 +/- 16 for a negative HUT (P = 0.5). In conclusion, the present study demonstrates a statistical association between anxiety (as determined by BAI) and HUT result. Gender-based analysis revealed a more statistically significant relationship between anxiety and HUT outcome for women as compared to men.