Inappropriate early hypotension in adolescents: a form of chronic orthostatic intolerance with defective dependent vasoconstriction.

Instantaneous orthostatic hypotension (INOH) has been reported in children and adolescents as a new entity of orthostatic intolerance in children who underwent rapid standing as an orthostatic stress test. Children with INOH were discovered among patients presenting with symptoms of chronic orthostatic intolerance, which is often related to orthostatic tachycardia. We used head-up tilt table testing at 70 degrees to investigate children presenting with symptoms of chronic orthostatic intolerance. We compared 24 patients aged 12-17 y, with chronic orthostatic intolerance and symptoms for >or=3 mo, with 13 healthy normal control patients. We recorded continuous heart rate, blood pressure, and respiratory rate and used venous occlusion strain gauge plethysmography to measure calf and forearm blood flow while supine and calf blood flow during head-up tilt. Patients with chronic orthostatic intolerance fulfilled criteria for the postural orthostatic tachycardia syndrome. Postural orthostatic tachycardia syndrome patients were divided into two groups by the occurrence of INOH. Supine forearm and calf arterial resistance was decreased in patients with INOH (n = 8) compared with postural orthostatic tachycardia syndrome patients without INOH (n = 16) and compared with control (n = 13). Resting calf venous pressure was elevated, suggesting excess venous filling because of vasodilation. During early head-up tilt, calf blood flow increased markedly in INOH, less in No-INOH, postural orthostatic tachycardia syndrome patients and least in control patients. Flow was temporally related to calf swelling and negatively correlated to hypotension. The data suggest that INOH occurs in patients with chronic orthostatic intolerance and orthostatic tachycardia and is related to rapid caudal blood flow when upright because of a vasoconstrictor defect.     

Physiologic neurocirculatory patterns in the head-up tilt test in children with orthostatic intolerance

Background: Orthostatic intolerance (OI) is a common clinical manifestation in clinical pediatrics. The head‐up tilt (HUT) table test is considered the standard of orthostatic assessment, but the physiologic neurocirculatory profile during HUT has not been fully realized in children with OI. The present study, therefore, was designed to investigate the physiologic patterns that occur during HUT in children with OI. Methods: Ninety children (56 girls; mean age, 11.6 ± 2.3 years) with OI underwent HUT under quiet circumstances. Blood pressure and heart rate were monitored simultaneously. Results: Forty‐nine children with OI (54.4%) had vasovagal response with HUT testing; 33 (36.7%), vasodepressor response; six (6.7%), cardioinhibitory response; and 10 (11.1%), mixed response. Twenty‐eight children (31.1%) had postural orthostatic tachycardia; one (1.1%), orthostatic hypotension (OH); and 12 (13.3%), normal physiologic response. Patterns of cerebral syncope response and chronotropic incompetence were not observed. Conclusions: Classical vasovagal response was the major physiologic pattern seen in children with OI during HUT testing, and postural orthostatic tachycardia response ranked second.     

Orthostatic intolerance in adolescent chronic fatigue syndrome

OBJECTIVES: To demonstrate the association between orthostatic intolerance and the chronic fatigue syndrome (CFS) in adolescents and to delineate the form that orthostatic intolerance takes in these children. STUDY DESIGN: We investigated the heart rate and blood pressure (BP) responses to head-up tilt (HUT) in 26 adolescents aged 11 to 19 years with CFS compared with responses in adolescents referred for the evaluation of simple faint and to responses in 13 normal healthy control children of similar age. RESULTS: A total of 4/13 of the controls and 18/26 simple faint patients experienced typical faints with an abrupt decrease in BP and heart rate associated with loss of consciousness. One CFS patient had a normal HUT. A total of 25/26 CFS patients experienced severe orthostatic symptoms associated with syncope in 7/25, orthostatic tachycardia with hypotension in 15/25, and orthostatic tachycardia without significant hypotension in 3/25. Acrocyanosis, cool extremities, and edema indicated venous pooling in 18/25. None of the control or simple faint patients experienced comparable acral or tachycardic findings. CONCLUSIONS: We conclude that chronic fatigue syndrome is highly related to orthostatic intolerance in adolescents. The orthostatic intolerance of CFS often has heart rate and BP responses similar to responses in the syndrome of orthostatic tachycardia suggesting that a partial autonomic defect may contribute to symptomatology in these patients.     

儿童体位性心动过速综合征的临床特征及随访研究

目的　探讨儿童体位性心动过速综合征 (POTS)的临床特征、诊断标准及治疗方案。方法　以符合诊断标准的 28例POTS患儿为研究对象,分析年龄分布、病程及基础血流动力学指标,同时观察其各种临床表现的发生频率及诊治效果。结果　诊断为POTS的患儿 28例,占 88例不明原因晕厥或起立后头晕就诊患儿的 32%,其中男 11例,女 17例。男∶女约为 1∶1.5。年龄 6~16岁,平均为(11.6±2.2)岁,其中 6~10岁 5例,占 18%, 10~16岁(包括 10岁)23例,占 82%。病程为 1个月~6年,平均(13.3±19.6)个月,半数以上在 6个月以内;最常见的临床表现为起立后出现头晕或眩晕、晕厥、胸闷、头痛、心悸、面色改变、视物模糊、倦怠、晨起不适等直立不耐受或直立调节障碍症状, 14例伴有恶心或呕吐等消化道症状;在直立试验(先安静平卧 10min,然后直立 10min)或直立倾斜试验(HUT)过程中,POTS患儿最常见的异常表现为在直立或倾斜后 10min内,心率增加≥35次 /min,部分患儿心率最大值≥120次 /min,出现异常表现的时间平均为 5min左右;但仅有 10例的患儿在直立后即出现异常表现, 18例患儿需要HUT确定诊断。12例POTS患儿曾被误诊为癫痫或心肌炎,误诊率达 43%。经过生活指导治疗及药物治疗的综合治疗后,大多数患儿症状可缓解或消失。结论　POTS常见     

Transient orthostatic hypotension is common in adolescents

OBJECTIVES: We hypothesized that transient hypotension associated with the symptom of lightheadedness with standing is a common phenomenon in healthy adolescents but may be mistaken for orthostatic intolerance. STUDY DESIGN: We studied 23 healthy adolescents, combining upright tilt to 70 degrees and to 35 degrees (in 12 patients) with continuous heart rate and blood pressure (BP) measurements. We measured peripheral blood flow and venous pressure in the arms and legs by using venous plethysmography. RESULTS: Healthy subjects with normal vasoconstrictive responses to sustained upright tilt uniformly have a transient fall in BP during 70 degrees upright tilt that varies from almost undetectable to large decreases in BP easily exceeding the 20-mm Hg threshold for orthostatic hypotension. Large decreases are associated with short-lived symptoms of lightheadedness and are most marked in those with the largest calf blood flow. The higher the flow, the lower the BP falls. There is appropriate reflex tachycardia. CONCLUSIONS: We conclude that transient orthostatic hypotension is common in many healthy adolescents, especially after prolonged recumbency, and is related to dependent vascular tone.     

Impaired postural cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance

OBJECTIVES: To measure postural changes in cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance. STUDY DESIGN: We studied 28 patients (age, 10 to 22 years) and 20 healthy control subjects (age, 6 to 27 years). Cerebral oxygenated hemoglobin (oxy-Hb) and deoxygenated Hb were noninvasively and continuously measured with near infrared spectroscopy during active standing. Beat-to-beat arterial pressure was monitored by Finapres. RESULTS: Orthostatic intolerance determined by cardiovascular responses to standing was observed in 16 of 28 patients: instantaneous orthostatic hypotension in 8, delayed orthostatic hypotension in 2, and postural orthostatic tachycardia in 6. A rapid recovery of oxy-Hb by near infrared spectroscopy at the onset of active standing was not found in 15 of 16 patients with chronic fatigue and orthostatic intolerance and in 6 of 12 patients with chronic fatigue without orthostatic intolerance but only in 2 of 20 control subjects. Thirteen of 16 patients with orthostatic intolerance showed prolonged reduction in oxy-Hb during standing. CONCLUSIONS: Impaired cerebral hemodynamics in patients with chronic fatigue syndrome and postural orthostatic tachycardia suggest a link between impaired cerebral oxygenation and chronic fatigue. However, this cannot explain the symptoms in patients meeting the criteria of chronic fatigue without orthostatic intolerance.     

Pharmacokinetics of pyridostigmine in a child with postural tachycardia syndrome

Pyridostigmine has been proposed for the treatment of postural orthostatic tachycardia syndrome in adults at a dose of 60 mg twice daily, but no dosing recommendation exists for children. With the approval of our local ethics board, we tested the pharmacokinetics of pyridostigmine in 6 children with myasthenia and a pediatric index patient with severe postural orthostatic tachycardia syndrome whose condition failed all conventional therapy and who had developed significant postural hypertension. Pyridostigmine was quantified by using a validated, semiautomated, and specific high-performance liquid chromatography/tandem mass spectrometry assay in combination with online column-switching extraction and turbo electrospray ionization. The patient with postural orthostatic tachycardia syndrome showed a dose-dependent favorable response to oral pyridostigmine. Pharmacokinetic evaluation revealed a short half-life of 2.29 hours, similar to the 2.0 +/- 0.63 hours in the patients with myasthenia. The patient with postural orthostatic tachycardia syndrome has subsequently been treated at a dose of 45 mg in the morning, 30 mg at lunchtime, and 15 mg at bedtime; after 9 months, there has been persistent positive effect and without additional blood pressure medication. No major adverse effects occurred. Pyridostigmine has been a safe and effective treatment modality for this child with postural orthostatic tachycardia syndrome. The short half-life suggests that dosing 3 times per day is preferable.     

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??Pediatric functional cardiovascular diseases involve a series of dysfunctions which can affect children’s physical and mental health. They include vasovagal syncope??postural tachycardia syndrome??orthostatic hypotension??orthostatic hypertension and beta-adrenoceptor hyperfunction??etc. Since the above-mentioned diseases have various therapeutic response??with the research progress of the disease mechanisms and prognosis??great progress has been made in individualized management of pediatric functional cardiovascular diseases. In the future??great attention should be paid to the individualized diagnosis and treatment of the diseases so as to improve the diagnostic and therapeutic technology.     

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目的探讨儿童体位性心动过速综合征(POTS)的临床特点。方法2008年5月至2009年10月于北京大学第一医院儿科门诊就诊,经直立试验或直立倾斜试验确诊POTS的患儿109例(POTS组),平均年龄(11.79±2.55)岁;20名健康儿童为对照组,平均年龄(11.55±3.65)岁。对每例POTS患儿详细询问病史并进行体格检查,对比分析两组儿童在生活习惯、家族史及体质特征方面特点,总结POTS组患儿发病的临床特征。结果与对照组相比,POTS组患儿在性别比例、年龄、身高、体重、平卧心率、平均动脉压方面差异无统计学意义。POTS患儿主要症状以晕厥多见(52.3%),42.2%症状发作频繁(就诊时>10次),主要症状发生季节以夏秋季多见(42.1%),发作持续时间多在1min以内(29%)。83.5%患儿发作前有诱因,发作诱因以持久站立为多见(50.5%),发作前多伴有先兆症状(78.0%),其中以头晕、黑矇、大汗、面色苍白最为常见。18例(16.5%)患儿有伴随症状,32例(29.4%)发作后仍有不适,以乏力最常见(24例)。90例(82.6%)患儿无既往疾病史,30例(27.6%)有直立不耐受家族史,46例(...     

Episodic hypertension in postural orthostatic tachycardia syndrome

We report the case of a 17-year-old woman who presented to the emergency department on several occasions due to palpitations, tachycardia, syncope, short spells of dizziness and light-headedness with complete spontaneous recovery, and hypertension. The patient had been evaluated by several specialists, and multiple complementary examinations had revealed no abnormalities that could explain the symptoms. Due to suspicion of orthostatic intolerance or postural orthostatic tachycardia syndrome with hypertension, the patient underwent a 60-degree tilt table test, which confirmed the diagnosis. The patient was successfully treated with bisoprolol. The physiopathological mechanisms, diagnosis, and treatment of this syndrome are reviewed.     

儿童体位性心动过速综合征合并血管迷走性晕厥的诊断探讨

目的：探讨儿童体位性心动过速综合征（POTS）合并血管迷走性晕厥（VVS）的诊断。方法：回顾性地复习2007年1月至2010年12月经直立倾斜试验（HUT）诊断为POTS的57例儿童的临床资料,其中男29例,女28例,年龄5～16(12.2±1.9)岁。结果：57例POTS儿童中,在可以耐受倾斜体位的前提下,通过延长HUT时间,24例(42%)经HUT诊断合并VVS,其中血管抑制型20例,混合型3例,心脏抑制型1例。合并VVS儿童平均年龄（13.0±1.4岁）大于未合并VVS的POTS儿童（11.5±2.1岁）,差异有统计学意义（P0.05）。结论：部分POTS儿童合并VVS,在可以耐受倾斜体位的前提下,延长HUT时间有利于防止VVS漏诊。与未合并VVS的POTS儿童比较,合并VVS儿童年龄较大,但性别、临床症状无明显差异。     

Japanese clinical guidelines for juvenile orthostatic dysregulation version 1

This clinical practice guideline provides recommendations for the assessment, diagnosis and treatment of school-aged children and juveniles with orthostatic dysregulation (OD), usually named orthostatic intolerance in USA and Europe. This guideline is intended for use by primary care clinicians working in primary care settings. The guideline contains the following recommendations for diagnosis of OD: (i) initial evaluation composed of including and excluding criteria, the assessment of no evidence of other disease including cardiac disease and so on; (ii) a new orthostatic test to determine four different subsets: instantaneous orthostatic hypotension, postural tachycardia syndrome, neurally mediated syncope and delayed orthostatic hypotension; (iii) evaluation of severity; and (iv) judgment of psychosocial background with the use of rating scales. The guideline also contains the following recommendations for treatment of OD on the basis of the result of an orthostatic test in addition to psychosocial assessment: (i) guidance and education for parents and children; (ii) non-pharmacological treatments; (iii) contact with school personnel; (iv) use of adrenoceptor stimulants and other medications; (v) strategies of psychosocial intervention; and (vi) psychotherapy. This clinical practice guideline is not intended as a sole source of guidance in the evaluation of children with OD. Rather, it is designed to assist primary care clinicians by providing a framework for decision making of diagnosis and treatments.     

以神经系统症状起病的儿童血管迷走性晕厥或体位性心动过速综合征88例临床分析

目的 探讨以神经系统症状起病的儿童血管迷走性晕厥（VVS）及体位性心动过速综合征（POTS）的临床特点，为该类疾病早期识别提供依据。方法 回顾性分析88例以一过性意识丧失、头晕、头痛及抽搐等神经系统症状为首发症状，最终确诊为VVS或POTS的患儿的临床资料。结果 88例患儿中，男性35例（40%），女性53例（60%），年龄4~15岁，发病高峰年龄10~13岁。88例患儿皆以一过性意识丧失、头晕、头痛及抽搐为首发症状，经脑电图、脑脊液及头颅磁共振等检查，排除了神经系统疾病，经直立倾斜试验（HUTT）最终确诊为VVS 53例（60%），POTS 35例（40%）。有5例以一过性意识丧失为首发症状的患儿被误诊为癫痫。59例（67%）患儿发病前可追溯到诱因，常见诱因依次为长时间站立、体位变化及剧烈运动。66例（75%）有发作先兆症状，常见的先兆症状依次为胸闷、消化道症状（恶心、呕吐及腹痛）及面色苍白。88例患儿均接受了健康教育、自主神经功能锻炼，53例VVS患儿予口服补液盐治疗，35例POTS患儿予口服补液盐联合美托洛尔治疗。对88例患儿进行为期18个月的随访，随访3、6、12、18个月时的治疗有效率分别为87%、93%、93%、90%。结论 以一过性意识丧失、头晕、头痛及抽搐为首发症状的患儿除了考虑神经系统疾病外，需警惕VVS及POTS等功能性心血管疾病，进一步HUTT检查可明确诊断；明确诊断后早期治疗可取得较好的疗效。     

A matched case control study of orthostatic intolerance in children/adolescents with chronic fatigue syndrome

This study aimed to define cardiovascular and heart rate variability (HRV) changes following head-up tilt (HUT) in children/adolescents with chronic fatigue syndrome (CFS) in comparison to age- and gender-matched controls. Twenty-six children/adolescents with CFS (11-19 y) and controls underwent 70-degree HUT for a maximum of 30 min, but returned to horizontal earlier at the participant's request with symptoms of orthostatic intolerance (OI) that included lightheadedness. Using electrocardiography and beat-beat finger blood pressure, a positive tilt was defined as OI with 1) neurally mediated hypotension (NMH); bradycardia (HR <75% of baseline), and hypotension [systolic pressure (SysP) drops >25 mm Hg)] or 2) postural orthostatic tachycardia syndrome (POTS); HR increase >30 bpm, or HR >120 bpm (with/without hypotension). Thirteen CFS and five controls exhibited OI generating a sensitivity and specificity for HUT of 50.0% and 80.8%, respectively. POTS without hypotension occurred in seven CFS subjects but no controls. POTS with hypotension and NMH occurred in both. Predominant sympathetic components to HRV on HUT were measured in CFS tilt-positive subjects. In conclusion, CFS subjects were more susceptible to OI than controls, the cardiovascular response predominantly manifest as POTS without hypotension, a response unique to CFS suggesting further investigation is warranted with respect to the pathophysiologic mechanisms involved.     

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目的探讨鉴别血管迷走性晕厥(VVS)及体位性心动过速综合征(POTS)的临床依据。方法 2009年4月至2011年4月于北京大学第一医院儿科门诊就诊并确诊为VVS的儿童40例,年龄6～18岁,平均(11.8±2.9)岁;POTS儿童165例,年龄5～19岁,平均(11.4±2.7)岁。评价与检查手段包括临床表现、家族史、生活习惯、直立试验以及直立倾斜试验。结果 VVS和POTS在儿童时期的共同特征包括学龄期及青春期多发、女孩稍多于男孩、发作季节以夏秋季多见、多数患儿有诱因和发作先兆、发作后仍有不适、平卧后症状可缓解。在VVS儿童中以晕厥为主要表现者明显多于POTS(P<0.001),在POTS儿童中,以头晕为表现的患儿明显多于VVS(P<0.001)。VVS患儿中父方有直立不耐受家族史者明显多于POTS患儿(P<0.05)。结论直立倾斜试验是鉴别VVS与POTS的重要客观检查手段。晕厥及头晕的发生频率对于临床鉴别诊断VVS与POTS具有参考价值。     

Autonomic nervous system dysfunction in adolescents with postural orthostatic tachycardia syndrome and chronic fatigue syndrome is characterized by attenuated vagal baroreflex and potentiated sympathetic vasomotion

The objective was to determine the nature of autonomic and vasomotor changes in adolescent patients with orthostatic tachycardia associated with the chronic fatigue syndrome (CFS) and the postural orthostatic tachycardia syndrome (POTS). Continuous electrocardiography and arterial tonometry was used to investigate the heart rate and blood pressure responses before and 3-5 min after head-up tilt in 22 adolescents with POTS and 14 adolescents with CFS, compared with control subjects comprising 10 healthy adolescents and 20 patients with simple faint. Heart rate and blood pressure variability, determined baroreceptor function using transfer function analysis, and measured cardiac vagal and adrenergic autonomic responses were calculated using timed breathing and the quantitative Valsalva maneuver. Two of 10 healthy controls and 14 of 20 simple faint patients experienced vasovagal syncope during head-up tilt. By design, all CFS and POTS patients experienced orthostatic tachycardia, often associated with hypotension. R-R interval and heart rate variability were decreased in CFS and POTS patients compared with control subjects and remained decreased with head-up tilt. Low-frequency (0.05-0.15 Hz) blood pressure variability reflecting vasomotion was increased in CFS and POTS patients compared with control subjects and increased further with head-up tilt. This was associated with depressed baroreflex transfer indicating baroreceptor attenuation through defective vagal efferent response. Only the sympathetic response remained. Heart rate variability declined progressively from normal healthy control subjects through syncope to POTS to CFS patients. Timed breathing and Valsalva maneuver were most often normal in CFS and POTS patients, although abnormalities in select individuals were found. Heart rate and blood pressure regulation in POTS and CFS patients are similar and indicate attenuated efferent vagal baroreflex associated with increased vasomotor tone. Loss of beat-to-beat heart rate control may contribute to a destabilized blood pressure resulting in orthostatic intolerance. The dysautonomia of orthostatic intolerance in POTS and in chronic fatigue are similar.     

Bladder diverticulum: clinicopathologic spectrum in pediatric patients

ABSTRACT Urinary bladder diverticula are a relatively rare finding in both the adult and pediatric population. Their presence in the adult population has long been associated with the development of urothelial carcinoma within the lesion. Our goal is to analyze a relatively large pediatric patient population with urinary bladder diverticula to expand the body of knowledge on the associated clinical symptomatology, congenital syndromes associated with the entity, and treatment methods and to further investigate if there is any reason to suspect malignant transformation within the pediatric population. A search for pediatric patients (0-19?years of age) from 1990 to 2011 revealed 47 patients with 60 diverticula within the specified age range. Clinical records and histologic slides for all cases were pulled for review, and statistical analysis was performed on the results. The most common findings were vesicoureteral reflux (68%), recurrent urinary tract infection (55%), and hydronephrosis (40%). Fourteen of 47 (30%) patients had an associated congenital syndrome/malformation. Diverticular size range was 0.5-10?cm with a mean of 2.56?cm. No patient was found to have overt malignancy or dysplastic changes within the diverticula or bladder at the time of pathologic evaluation. High association with recognizable clinical symptoms and additional urinary tract abnormalities leads to early identification and treatment. A sizable percentage of those found to have bladder diverticula within the pediatric population will have a congenital syndrome. No association with malignancy is seen within pediatric bladder diverticula; it is an extremely unlikely event in these young patients.     

The relation between hyperventilation and pediatric syncope

OBJECTIVE: The objective was to evaluate prospectively the role of hyperventilation in the development of neurocardiogenic syncope in children during head-upright tilt testing (HUTT).Study design: Tilt testing was performed in 34 children (mean age 10.6 years) with clinical suspicion of syncope. Respiratory rate and end-tidal carbon dioxide pressure were continuously monitored during HUTT. RESULTS: Tilt test was negative in 12 cases; 3 (25%) patients of this group exhibited hyperventilation any time during the test. In the remaining 22 cases the HUTT was positive, and 15 (68.2%) patients of this group exhibited hyperventilation at the onset of clinical symptoms and during syncope. In the positive HUTT group, the mean time elapsed from the tilt to the onset of syncope and the mean time elapsed from the onset of clinical symptoms to syncope (latency time) were significantly longer for patients who hyperventilated than for those who did not hyperventilate, (21.8 vs 11.5 minutes) (P =.002) and (78 vs 51 seconds) (P =.04), respectively. CONCLUSIONS: Spontaneous hyperventilation could play a relevant role in the pathophysiology of pediatric neurocardiogenic syncope, and it could point out a specific subtype of response to orthostatic stress in susceptible patients. We suggest the inclusion of capnography in tilt-test protocols could improve the assessment of syncope in children.     

Clinical and electrophysiological characteristics in children with atrioventricular nodal reentrant tachycardia

Atrioventricular (AV) nodal reentrant tachycardia is one of the most common supraventricular tachycardias in childhood. However, information about AV nodal reentrant tachycardia in childhood is limited, especially about the variant and multiple forms. The purpose of this retrospective study was to investigate the clinical and electrophysiological characteristics in pediatric patients with AV nodal reentrant tachycardia. Forty-eight pediatric patients with AV nodal reentrant tachycardia were included (ages 11-18 years; 25 males and 23 females). The age of onset and duration of symptoms were significantly younger and shorter in pediatric patients, respectively. A higher incidence of antegrade dual AV nodal pathways was found in adult patients than pediatric patients (72.9 vs 52.1% p = 0.003). Both antegrade and retrograde slow pathway functions were better in pediatric than adult patients. There was no significant difference between children and adults in the occurrence of variant and multiple forms of AV nodal reentrant tachycardia. This study demonstrated that pediatric patients have different electrophysiologic characteristics from those of adult patients.