Compression Garment Reduces Orthostatic Tachycardia and Symptoms in Patients With Postural Orthostatic Tachycardia Syndrome

BackgroundPostural orthostatic tachycardia syndrome (POTS) is a chronic form of orthostatic intolerance associated with a significant symptom burden. Compression garments are a frequently prescribed treatment, but the effectiveness of waist-high compression has not been evaluated in adults with POTS.ObjectivesThis study evaluated compression garments as a treatment for POTS using a head-up tilt test (HUT), and a noninflatable core and lower body compression garment.MethodsThirty participants completed 10-min HUT with each of 4 compression conditions in a randomized crossover design. The conditions were no compression (NONE), lower leg compression (LEG), abdominal/thigh compression (ABDO), and full abdominal/leg compression (FULL). Heart rate, beat-to-beat blood pressure, and Vanderbilt Orthostatic Symptom Score ratings were measured during each HUT.ResultsThe compression garment reduced heart rate (NONE: 109 ± 19 beats/min; LEG: 103 ± 16 beats/min; ABDO: 97 ± 15 beats/min; FULL: 92 ± 14 beats/min; p < 0.001) and improved symptoms (p < 0.001) during HUT in a dose-dependent manner. During HUT, stroke volume and systolic blood pressure were better maintained with FULL and ABDO compression compared with LEG and NONE compression.ConclusionsAbdominal and lower body compression reduced heart rate and improved symptoms during HUT in adult patients with POTS. These effects were driven by improved stroke volume with compression. Abdominal compression alone might also provide a clinical benefit if full lower body compression is not well tolerated. (Hemodynamic Effects of Compression in POTS; NCT03484273)     

不明原因晕厥患者直立倾斜试验反应特点

目的探讨不明原因晕厥(UPS)患者直立倾斜试验(HUTT)的反应特点。方法2005-01～2006-09在我院就诊或住院的UPS或接近晕厥患者170例,男性64例,女性106例,年龄3～70岁,平均(23.18±15.40)岁,其中儿童(<18岁)88例。比较HUTT阳性与阴性患者的特点,调查阳性患者反应类型与性别、年龄的关系及不同类型阳性反应患者HUTT期间血流动力学的变化。结果①对HUTT结果有显著影响的因素为年龄和HUTT期间的心电图变化。②血管抑制型和混合型在男女性别间比较差异无统计学意义(P>0.05),但在成人(≥18岁)和儿童(<18岁)组间比较差异有统计学意义(P<0.05),血管抑制型和心脏抑制型多见于儿童。③HUTT阳性者心律失常事件发生率较阴性者高,常见窦性心律不齐、窦性心动过缓、窦性心动过速、交界性心律和逸搏。④基础倾斜试验(BHUT)晕厥发作平均时间为(21.61±10.64)min,舌下含服硝酸甘油倾斜试验(SNHUT)晕厥发作平均时间为舌下含服硝酸甘油后(5.58±2.68)min。结论①儿童较成人易于发生阳性反应,以血管抑制型和心脏抑制型居多。②HUTT期间出现心电图变化者阳性反应发生的可能性增加,尤其是窦性心律不齐和窦性心动过缓出现时要警惕阳性反应的发生。     

Age of first faint in patients with vasovagal syncope

INTRODUCTION: Understanding whether vasovagal syncope is a lifelong disorder might shed insight into its physiology and affect management strategies. Accordingly, we determined the age of the first syncopal spell in adult patients who sought care for syncope. METHODS AND RESULTS: Patients were 42 +/- 18 years old with 64% women. They had had a median 8 syncope spells (interquartile range [IQR]: 4, 20) with a median frequency of 1.0 syncopal spells per year. The range of syncopal spells was 1-3,375, and the range of duration of history of syncope was 0.003-70 years. The first syncopal spell occurred at ages 0-81 in a skewed distribution, with a marked mode age of 13 years, a median age of 18 years (IQR 12, 37), and a mean age of 26 +/- 20 years. The distributions were statistically indistinguishable across countries (P = 0.50), among Canadian regions (P = 0.69), and between the studies (P = 0.49). The same modal values were seen in males and females, and in patients <40 and > or =40 years old. However, patients > or =40 years had median ages of onset older than patients <40 years (36 +/- 23 vs 17 +/- 8 years). Patients had a recalled history of syncopal spells of median duration of 10 years (IQR: 2, 23), with a range of 0.003-70 years. An age of onset <44 years was 86% accurate for vasovagal syncope. CONCLUSION: The most common age at which vasovagal syncope first presents is 13 years, and patients remain at risk of syncope for many years. Lifelong coping strategies may be desirable.     

Impact of age and blood pressure on the lower arterial pressure limit for maintenance of consciousness during passive upright posture in healthy vasovagal fainters: preliminary observations.

Maintenance of consciousness importantly depends on systemic arterial blood pressure (BP) remaining above the lower pressure limit for cerebrovascular autoregulation. This study evaluated the impact of age and baseline arterial blood pressure (BP) on the BP recorded at onset of syncope in otherwise healthy individuals undergoing passive head-up tilt (HUT) testing for suspected vasovagal syncope. Since hypertension is thought to shift the lower autoregulation point to higher values, and since older healthy patients tend to have higher BP than younger individuals, we hypothesized that even among healthy individuals HUT-induced syncope would occur at higher BP in older compared with younger subjects. Three groups of otherwise healthy individuals who had positive HUT were identified: Group 1: <25 years, n=17; Group 2: 25-59 years, n=18; and Group 3: > or =60 years, n=7. As expected, baseline arterial systolic blood pressure of patients > or =60 years (162+/-37 mmHg) was significantly higher than in the other two groups (Group 1: <25 years, 116+/-15 mmHg; Group 2: 25-59 years, 128+/-12 mmHg). Further, the > or =60 age group tolerated upright posture for a longer period before syncope than did younger patients. However, despite a trend for BP at syncope to increase with age, differences were small (Group 3: > or =60 years, 61+/-15 mmHg, Group 2: 25-59 years, 58+/-6 mmHg, and Group 1: 54+/-16 mmHg) and were not statistically significant. Thus, in generally healthy individuals, age and baseline BP has only a minor effect on the lower limit of BP necessary for maintenance of consciousness. On the other hand, higher baseline BP provides older individuals a greater blood pressure 'reserve' for maintenance of consciousness compared with younger subjects.     

Usefulness of midodrine in patients with severely symptomatic neurocardiogenic syncope: a randomized control study

INTRODUCTION: The efficacy of midodrine for the management of patients with neurocardiogenic syncope was assessed prospectively in a randomized control study. METHODS AND RESULTS: Patients who had at least monthly occurrences of syncope and a positive tilt-table test were included in the study. A total of 61 patients were randomly allocated to treatment either with midodrine or with fluid, salt tablets, and counseling. Midodrine was given at a starting dose of 5 mg three times a day and increased up to a dose of 15 mg three times a day when required. Midodrine was given during the daytime every 6 hours. Thirty-one patients were assigned to treatment with midodrine; the other 30 patients were advised to increase their fluid intake and were instructed to recognize their prodromes and abort the progression to syncope. Patients were followed-up for at least 6 months. A quality-of-life questionnaire was administered at the time of randomization and 6 months after. At the 6-month follow-up, 25 (81%) of 31 midodrine-treated patients and 4 (13%) of the 30 fluid-therapy patients had remained asymptomatic (P < 0.001). One patient had to discontinue taking midodrine due to severe side effects and another six patients experienced minor side effects that did not require drug discontinuation. CONCLUSION: Midodrine appeared to provide a significant benefit in patients with neurocardiogenic syncope. To prevent recurrence of symptoms, dose adjustments were required in about one third of patients.     

心脏抑制型血管迷走性晕厥患者倾斜试验阳性的重复性观察

目的　总结心脏抑制型血管迷走性晕厥倾斜试验阳性重复性。方法　对 46例首次倾斜试验阳性并表现为心脏抑制型血管迷走性晕厥的患者在 1或 3 d相同的时间进行重复倾斜试验。结果　39例诱发出晕厥或晕厥前症状 ,倾斜试验阳性 ,其阳性重复性为 84.4% ,其中 ,30例表现为心脏抑制型 ,6例表现为混合型 ,3例表现为血管减压型。结论　心脏抑制型血管迷走性晕厥患者倾斜试验阳性的类型可以发生变化     

QT间期离散度对儿童及青少年心脏抑制型血管迷走性晕厥的诊断效能及预后估测价值

目的:探讨QT间期离散度(QT interval dispersion,QTd)对儿童及青少年心脏抑制型血管迷走性晕厥(cardioinhibitory vasovagal syncope,VVS-CI)的诊断效能及预后估测价值。方法:选择2010年7月至2020年1月因晕厥或晕厥先兆在中南大学湘雅二医院儿童晕厥专科门诊首次就诊或住院、明确诊断为VVS-CI的儿童及青少年80例为VVS-CI组,匹配同期在本院进行健康体检的儿童及青少年80例为对照组。测量两组基础状态下12导联心电图QT间期。结果:(1)两组比较:VVS-CI组较对照组心率降低( P<0.05),最大QT间期(maximum QT interval,QTmax)、最小QT间期(minimum QT interval,QTmin)、QTd、校正最大QT间期(corrected maximum QT interval,QTcmax)、校正QT间期离散度(corrected QT interval dispersion,QTcd)延长( P<0.05)。随访84(45,127)d,无反应组较有反应组QTmax、QTd、QTcmax、校正最小QT间期(corrected minimum QT interval,QTcmin)、QTcd延长( P<0.05)。(2)诊断效能:QTmax、QTmin、QTd、QTcmax、QTcd对儿童及青少年VVS-CI有诊断价值( P<0.001)。QTd的曲线下面积(area under the curve,AUC)最大(0.914),最佳截断值为28.50 ms,诊断VVS-CI的敏感度为86.30%,特异度为84.95%。(3)预后估测价值:QTmax、QTd、QTcmax、QTcmin、QTcd对儿童及青少年VVS-CI预后有估测价值( P<0.05或0.01)。QTd的AUC最大(0.906),最佳截断值为34.50 ms,预测对VVS-CI干预有反应的敏感度为90.00%,特异度为82.35%。 结论:心电图QTd对儿童及青少年VVS-CI的诊断及预后有较好的估测价值。     

Usefulness and safety of shortened head-up tilt testing potentiated with sublingual glyceryl trinitrate in older patients with recurrent unexplained syncope

OBJECTIVES: To evaluate the sensitivity and tolerability of shortened, glyceryl trinitrate (GTN)-potentiated, head-up tilt test (HUT) in patients older and younger than 65 with unexplained syncope and to compare the specificity of GTN-potentiated HUT (GTN-HUT) in older and younger controls. DESIGN: Methodological study. SETTING: Syncope units in secondary and tertiary hospitals. PARTICIPANTS: Three hundred twenty-four consecutive patients with unexplained syncope (100 aged > or =65 (mean age +/- standard deviation 73 +/- 6; 35 men) and 224 aged <65 (41 +/- 15; 111 men)) and 64 controls (29 aged > or =65 (73 +/- 6; 13 men) and 35 aged <65 (42 +/- 13; 16 men)). INTERVENTION: Patients and controls were tilted upright to 60 degrees for 20 minutes. If syncope did not occur, sublingual GTN (400 microg) was administered and 60 degrees HUT was continued for 15 minutes. Responses were classified as positive, negative, or exaggerated (slow decrease in blood pressure with a slight decrease in heart rate after GTN). MEASUREMENTS: Electrocardiogram and arterial pressure were monitored continuously. RESULTS: GTN-HUT was positive in 60% and 66% (NS), negative in 29% and 33% (NS), and exaggerated in 11% and 1% (P <.001) of older and younger patients, respectively. In older and younger controls, the GTN-HUT was negative in 70% and 86% and exaggerated in 28% and 9% of cases, respectively, (P <.05). The overall specificity (considering as negative also the exaggerated responses) was 97% in older and 94% in younger subjects. No patient or control experienced serious side effects. CONCLUSION: The shortened GTN-HUT provides satisfactory positivity rate and specificity in older patients. This test may be considered as a diagnostic tool in assessing recurrent unexplained syncope in older patients.     

Clinical efficacy of propantheline bromide in neurocardiogenic syncope: Pharmacodynamic implications

Summary The pharmacological response with tilt-table testing predicts long-term efficacy in neurocardiogenic syncope. However, beta-blockers for neurocardiogenic syncope are often not tolerated or are ineffective. Since cholinergic tone is important in the efferent part of the neurocardiogenic reflex, we investigated the pharmacodynamics and efficacy of propantheline bromide in preventing neurocardiogenic syncope. We studied 16 patients (11 males) with a mean age of 48.8 (± 15.1) years with presyncope or syncope and who had positive baseline tilt-table studies at a mean of 15.8 (± 10.3) minutes into the upright 60° tilt. They were given propantheline bromide orally, an anticholinergic agent, at a dose of 64.3 (± 21.8) mg/day for 7 days, and tilt-table testing was repeated 1 hour after readministration of propantheline bromide, 30 mg orally. After propantheline bromide treatment, 13 of 16 patients (81%) had no inducible presyncope or syncope on repeat tilt-table testing. In this group of responders, the mean minimum heart rate during upright tilt-table testing increased from 43.2 (± 77.3) beats/min to 77.3 (± 17.2) beats/min after propantheline bromide (p<0.005). More significantly, the minimum mean arterial blood pressure increased from 42.2 (± 25) mmHg to 81.3 (± 16.7) mmHg (p<0.0005) during upright tilt. At a follow-up of 15.2 (± 7.4) months, in the responder group (12 patients with long-term follow-up), the average dose of propantheline bromide was 32.5 (± 23.8) mg/day, which was significantly reduced from the initial dose (p<0.05). A clinical recurrence of symptoms occurred in only 4 out of 12 patients on propantheline bromide (33%), none of which were directly attributable to drug failure. It was concluded from this study that propantheline bromide is highly effective in preventing neurocardiogenic syncope. In addition, propantheline bromide's effectiveness is more than would be expected by prevention of cardioinhibition in neurocardiogenic syncope and would support a role for direct cholinergic control of vascular tone.This work was presented in part at the American Heart Association 67th Scientific Sessions, Dallas, Texas, November 14, 1994.     

肾素—血管紧张素系统在血管迷走性晕厥中的作用

本研究采用直立倾斜80°的方法观察了14例（21～52岁）有反复晕厥史的血管迷走性晕厥患者及10例（25～51岁）无晕厥史的健康对照者。分别在平卧位、倾斜位即刻、2、5、10、15、20、25分钟或晕厥发作时采静脉血测血浆肾素活性（PRA）、血浆血管紧张江Ⅱ（AⅡ）及醛固酮（ALD）的浓度。结果显示，患者在发生晕厥时（n＝9），血压显著下降，PRA、AⅡ、ALD浓度迅速增加，显著高于未发生晕厥的患者（n＝5）及正常对照（n＝10）。研究表明，循环肾素（R）、AⅡ和ALD都迅速参与体循环的调节作用，但它们的增高不是引起晕厥的直接原因，而是对血压下降的代偿性反应。