Coefficient of variation of heart rate and blood pressure in rapid identification of children with suspected orthostatic intolerance / 中华儿科杂志

Objective: To investigate the clinical value of coefficient of variation of heart rate and blood pressure in rapid identification of children with suspected orthostatic intolerance(OI). Methods: This was a retrospective study. The medical records of 379 children with OI were collected, who were admitted to the Department of Pediatrics of Qilu Hospital of Shandong University from January 2015 to January 2020. Another 20 out-patient children without syncope or syncope aura were selected as control. According to the results of standing test and head-up tilt test (HUTT), all the patients with OI were divided into the following 4 groups: vasovagal syncope (VVS) group, postural tachycardia syndrome (POTS) group, POTS combined with VVS (POTS+VVS) group and HUTT negative group. Then, coefficient of variation of systolic pressure (SBPCV), coefficient of variation of diastolic pressure (DBPCV) and coefficient of variation of heart rate (HRCV) in standing test and HUTT were calculated. Kruskal-Wallis test was used for comparison among the five groups, and Dunnett's T3 method for comparison between two groups. Paired t test was used to compare the coefficient of variation between supine and erect position and tilt position in each group. The predictive values of HRCV,SBPCV and DBPCV for negative HUTT were evaluated by receiver operating characteristic (ROC) curve. Results: Among the 379 children, there were 79 in HUTT negative group, 208 in VVS group, 52 in POTS group, and 40 in POTS+VVS group. The SBPCV of supine-erect position of the control group, HUTT negative group, VVS group, POTS group, POTS+VVS group were (3.8±1.0)%, (5.3±2.2)%, (6.6±3.4)%, (5.9±3.6)%, (6.9±2.8)%, respectively. Similarly, the SBPCV of supine, erect and head-up tilt position were (4.5±0.8)%, (6.0±1.9)%, (7.1±2.6)%, (6.0±2.1)%, (7.3±2.5)%; the DBPCV of supine-erect position were (7.3±1.2)%, (9.1±3.7)%, (9.1±4.9)%, (9.1±4.8)%, (11.6±4.6)%; the DBPCV of supine, erect and tilt position were (7.4±1.1)%, (9.4±2.9)%, (10.1±3.8)%, (9.2±3.3)%, (11.0±4.7)%; the HRCV of supine-erect position were (7.6±2.6)%, (12.9±3.7)%, (16.2±4.3)%, (21.2±5.9)%, (24.9±5.3)%; and the HRCV of supine, erect and tilt position were (8.1±1.6)%, (10.1±2.7)%, (14.1±4.3)%, (15.6±3.7)%, (18.9±4.0)%, respectively. All the indexes showed significant differences among the five groups (χ2=21.91, 25.47, 19.82, 14.65, 104.52, 92.51, all P<0.05). ROC curve analysis showed that when the SBPCV and HRCV of supine-erect position reached 4.4% and 10.5%, the area under the curve of ROC were 0.713 and 0.877, the sensitivity of predicting negative HUTT were 58.2% and 78.5%, and the specificity were 80.0% and 95.0%, respectively. Conclusions: Coefficient of variation of heart rate and blood pressure may serve as potential diagnostic indexes in evaluating autonomic function of OI patients. SBPCV ≥ 4.4% or HRCV ≥ 10.5% of supine-erect position could be an indication of HUTT.

Syncope in patients with cardiac pacemakers

Abstract Introduction: It is challenging to diagnose syncope in patients with pacemakers. Because these patients have increased morbidity and mortality risks, they require immediate attention to determine the causes in order to provide appropriate treatment. This study aimed to investigate the causes and predictive factors of syncope as well as the methods used to diagnose syncope in cardiac pacemaker patients. Methods: Patients with pacemakers implanted owing to sinus node disease or atrioventricular block were evaluated with standardized questionnaires, endocavitary electrograms, and other tests based on the suspected causes of syncope. Mann-Whitney U tests were used to analyze continuous variables and Chi-squared or Fisher's exact tests were used for categorical variables. Logistic regression was used for multivariate analyses. Statistical significance was P<0.05. Results: The study included 95 patients with pacemakers: 47 experienced syncope in the last 12 months and 48 did not. Of the 100 documented episodes of syncope, 48.9% were vasovagal syncopes, 17% had cardiac-related causes, 10.6% had unknown causes, and 8.5% had pacemaker failure. The multivariate analysis showed that a New York Heart Association (NYHA) Functional Class II was a significant factor for developing syncope (P<0.01). Conclusion: While the most common type of syncope in pacemaker patients was neurally mediated, it is important to perform detailed evaluations in this population as the causes of syncope can be life-threatening. The best diagnostic methods were stored electrogram analysis and the tilt table test. NYHA Functional Class II patients were found to have a higher risk for syncope.

Pediatric patients head-up-tilt-test with pharmacological challenge, it is safe? / Mesa inclinada en pacientes pediátricos con reto farmacológico, ¿es seguro?

Abstract Syncope in pediatrics represents an important cause of visits to the emergency units. For this reason, excluding a cardiac or malignant origin is essential at the time of the initial approach to determine what is the next step in management, or if they need to be referred to a pediatric cardiologist and/or electrophysiologist. Vasovagal syncope is the most frequent cause of syncope in pediatrics, in which a detailed clinical history is enough to make the diagnosis. If no diagnosis is concluded by the history, or if it is necessary to define the hemodynamic response of the patients, the head-up-tilt-test is indicated; this will trigger syncope due to an orthostatic stress caused by the angulated table (passive phase). If a negative response remains, it can be followed by a pharmacologic challenge to trigger the hemodynamic response, which is still controversial in pediatrics. The pharmacologic challenge increases the sensitivity with a slight reduction in test specificity. Although there is not a specific drug for the challenge in pediatric patients yet, the most commonly drugs used are nitrates and isoproterenol, the latter related to a great number of adverse effects. Sublingual administration of nitrates in the challenge has been proven to be ideal, effective, and safe in this specific age group. The aim of this article is to make a literature search to demonstrate the effectiveness and safety of the pharmacologic challenge during the head-up-tilt-test in pediatrics, emphasizing a study conducted at the National Institute of Cardiology with isosorbide dinitrate.

Resumen El síncope en edades pediátricas representa una causa importante en las visitas a unidades de urgencias, por lo que excluir un origen cardíaco o maligno es fundamental al momento del abordaje inicial para determinar la conducta a seguir o la necesidad de derivar al cardiólogo pediatra o electrofisiólogo. El síncope vasovagal (SVV) es la causa más frecuente de síncope en pediatría, para cuyo diagnóstico basta una historia clínica detallada. Cuando ésta no es suficiente para determinar el diagnóstico de síncope reflejo o es necesario definir el tipo de respuesta que lo origina, está indicada una prueba de mesa inclinada que produce un estrés ortostático por la angulación y ello desencadena un síncope (fase pasiva). En pruebas no concluyentes está indicado un reto farmacológico para precipitar la respuesta hemodinámica, pero aún es un tema de controversia en edades pediátricas. El reto farmacológico incrementa la sensibilidad de la prueba, con una ligera reducción de la especificidad. Si bien no existe todavía un medicamento específico para la población pediátrica, los más empleados son los nitratos y el isoproterenol, este último relacionado con un mayor número de efectos adversos. La administración sublingual de los nitratos utilizados ha demostrado ser ideal, efectiva y segura en los pacientes pediátricos. El objetivo del artículo es realizar una revisión de las publicaciones médicas que demuestran la efectividad y seguridad del reto farmacológico durante la prueba de mesa inclinada en pacientes pediátricos, con énfasis en un estudio conducido en el Instituto Nacional de Cardiología con dinitrato de isosorbida (DNIS).

Increased sympathetic cardiac autonomic modulation after two consecutive tilt tests in women with polycystic ovary syndrome / Aumento da modulação autonômica cardíaca simpática após dois testes de inclinação consecutivos em mulheres com síndrome dos ovários policísticos

Abstract Objective The present study aimed to analyze cardiac autonomic modulation via spectral and symbolic analysis of heart rate variability (HRV) in women with polycystic ovary syndrome (PCOS) who were subjected to two consecutive tilt tests. Methods A total of 64 women were selected and divided into 2 groups: control (without PCOS), and PCOS. Concentrations of follicle-stimulating hormone, luteinizing hormone, prolactin, estradiol, homocysteine, sex hormone-binding globulin, thyroid stimulating hormone, fasting insulin, testosterone, androstenedione, and 17-hydroxyprogesterone levels, triglycerides, free androgen index (FAI), and homeostasis assessment model (HOMA-IR) were assessed. Cardiac autonomic modulation was evaluated by spectral and symbolic analyses during two consecutive tilt tests (two moments) and supine moments before, between and after (three moments) the tilt tests. Results Women with PCOS had higher fasting insulin, HOMA-IR indexes, testosterone and FAI. Additionally, we observed that the PCOS group had greater sympathetic autonomic cardiac modulation in supine 2, tilt 1, and supine 3 moments compared with controls. Conclusion Women with PCOS had higher autonomic sympathetic cardiac modulation even after a second tilt test. No adaptation to this provocative test was observed. Spectral analysis was more sensitive for identifying differences between groups than the symbolic analysis.

Resumo Objetivo O presente estudo teve como objetivo analisar a modulação autonômica cardíaca por análise espectral e simbólica da variabilidade da frequência cardíaca (VFC) em mulheres com síndrome dos ovários policísticos (SOP) que foram submetidas a dois testes consecutivos de inclinação. Métodos Um total de 64 mulheres foram selecionadas e divididas em 2 grupos: controle (sem SOP) e SOP. Concentrações de hormônio folículo-estimulante, hormônio luteinizante, prolactina, estradiol, homocisteína, globulina de ligação a hormônios sexuais, hormônio estimulante da tireóide, insulina em jejum, testosterona e androstenediona e níveis de 17-hidroxiprogesterona, triglicerídeos, índice de andrógeno livre (FAI) e homeostase modelo de avaliação (HOMA-IR) foram avaliados. A modulação autonômica cardíaca foi avaliada por análises espectrais e simbólicas durante dois testes de inclinação consecutivos (dois momentos) e momentos supinos antes, entre e após (três momentos) os testes de inclinação. Resultados Mulheres com SOP apresentaram insulina em jejuM, índices HOMA-IR, testosterona e FAI mais altos. Além disso, observamos que o grupo PCOS apresentou maior modulação cardíaca autonômica simpática nos momentos supino 2, inclinado 1 e supino 3 em comparação aos controles. Conclusão Mulheres com SOP apresentaram modulação cardíaca simpática autonômica mais alta mesmo após um segundo teste de inclinação. Nenhuma adaptação a esse teste provocativo foi observada. A análise espectral foi mais sensível para identificar diferenças entre os grupos do que a análise simbólica.

Vasovagal syncope or postural orthostatic tachycardia syndrome in children with neurological symptoms at disease onset: a clinical analysis of 88 cases / 中国当代儿科杂志

OBJECTIVE@#To study the clinical features of vasovagal syncope (VVS) and postural orthostatic tachycardia syndrome (POTS) in children with neurological symptoms at disease onset.@*METHODS@#A retrospective analysis was performed on the medical data of 88 children with the initial symptoms of the nervous system, such as transient loss of consciousness, dizziness, headache, and convulsion, who were finally diagnosed with VVS or POTS.@*RESULTS@#Of the 88 children, there were 35 boys (40%) and 53 girls (60%), with an age of 4-15 years. The peak age of onset was between 10 and 13 years. All the children had the initial symptoms of transient loss of consciousness, dizziness, headache, and convulsion. Nervous system diseases were excluded by electroencephalography, cerebrospinal fluid examination, and cranial MRI. Of the 88 children, 53 (60%) were confirmed with VVS, and 35 (40%) with POTS, according to the results of head-up tilt test (HUTT). Five children with the initial symptom of transient loss of consciousness were misdiagnosed with epilepsy. Predisposing factors were determined for 59 children (67%), and prolonged standing was the most common factor, followed by change in body position and strenuous exercise. Premonitory symptoms were observed in 66 children (75%), among which chest discomfort was the most common symptom, followed by gastrointestinal symptoms (nausea, vomiting, and abdominal pain) and pale complexion. All 88 children received health education and exercise for autonomic nerve function, among whom 53 children with VVS were given oral rehydration salts and 35 children with POTS were given oral rehydration salts and metoprolol. All 88 children were followed up for 18 months, and the response rates to the above treatment at 3, 6, 12, and 18 months of follow-up were 87%, 93%, 93%, and 90% respectively.@*CONCLUSIONS@#In addition to nervous system diseases, functional cardiovascular diseases including VVS and POTS should be considered for children with the initial symptoms of transient loss of consciousness, dizziness, headache, and convulsion. HUTT can be used to make a confirmed diagnosis, and the early treatment can achieve a good outcome.

Efficiency of heart rate and heart rate difference at different time points during head-up tilt test in the diagnosis of postural tachycardia syndrome in children and adolescents / 中国当代儿科杂志

OBJECTIVE@#To study the efficiency of heart rate (HR) and heart rate difference (HRD) at different time points during head-up tilt test (HUTT) in the diagnosis of postural tachycardia syndrome (POTS) in children and adolescents.@*METHODS@#A total of 217 children and adolescents, aged 6-16 years, who were diagnosed with POTS were enrolled as the POTS group, and 73 healthy children and adolescents, matched for sex and age, were enrolled as the control group. The POTS group was further divided into ≤12 years old group with 127 children/adolescents and >12 years old group with 90 children/adolescents. The two groups were compared in terms of HR at baseline and at 5 and 10 minutes of HUTT (HR0, HR5, and HR10 respectively), difference between HR5/HR10 and HR0 (HRD5 and HRD10 respectively). The efficiency of HR5, HR10, HRD5 and HRD10 in the diagnosis of POTS was assessed.@*RESULTS@#Compared with the control group, the POTS group had significant increases in HR5, HR10, HRD5, and HRD10 (P12 years old subgroup (P<0.05), while the coincidence rate of HRD for the diagnosis of POTS was higher in the ≤12 years old subgroup (P<0.05). The combination of HR5, HR10, HRD5, and HRD10 for the diagnosis of POTS had a greater area under the curve (0.974; 95%CI: 0.949-0.989) than HR5, HR10, HRD5, or HRD10 alone, with a sensitivity of 87.80% and a specificity of 95.83%. The diagnostic efficacy of HRD for POTS was higher than that of HR (P<0.05).@*CONCLUSIONS@#HR and HRD at different time points during HUTT have a good value in the diagnosis of POTS in children and adolescents, and the accuracy of diagnosis varies with age and gender.

Síncope / Syncope

El síncope es una pérdida transitoria de conciencia y tono postural debido a hipoflujo sanguíneo cerebral que se recupera espontáneamente sin maniobras de RCP. En esta actualización se plantea el síncope vasovagal con sus diagnósticos diferenciales y posibles etiologías, fisiopatología y métodos de estudios. También se presenta la experiencia sobre este tema en nuestro hospital su estudio, tratamiento y diagnostico (tilt test) (AU)

Syncope is a transient loss of consciousness and postural tone due to cerebral blood hypoflow that recovers spontaneously without CPR maneuvers. This update discusses vasovagal syncope with its differential diagnoses and possible etiologies, pathophysiology, and diagnostic methods. Additionally, the experience on this topic of our hospital regarding investigations, treatment, and diagnosis is presented. (AU)

Polymorphisms in ß-adrenergic receptors are associated with increased risk to have a positive head-up tilt table test in patients with vasovagal syncope

Abstract Background Vasovagal syncope (VVS) is a frequent clinical condition in which a genetic background seems to be implicated. Considering that the adrenergic receptors (ARs) may play a role in VVS, the present study has as principal aim to determine if the α- and β-AR (ADRA and ADRB) gene polymorphisms are associated with an increased risk to have a positive head-up tilt table (HUTT) test in patients with VVS. Methods: Nine polymorphisms in the ADRA1A (rs1048101, rs1383914, rs574584, and rs573542), ADRB1 (rs1801252 and rs1801253), ADRB2 (rs1042713 and rs1042714), and ADRB3 (rs4994) genes were analyzed using the 5’ exonuclease TaqMan genotyping assay in a group of 134 patients with VVS. Results Under different models, the rs1801252 (OR = 8.63, 95% CI: 0.95-78.72, Precessive = 0.02), rs1042713 (OR = 1.94, 95% CI: 1.02-3.66, Padditive = 0.04), and rs4994 (OR = 2.46, 95% CI: 1.01-6.01, Pdominant = 0.042 and OR = 2.62, 95% CI: 1.04-6.63, Pover-dominant = 0.03) polymorphisms were associated with increased risk for a positive HUTT. All models were adjusted for statistically significant covariates. Conclusion These results suggest that some polymorphisms of the β-AR genes could contribute to a positive tilt test in patients with VVS.

Prediction of syncope with nonlinear dynamic analysis during head-up tilt in vasovagal syncope patients / 北京大学学报(医学版)

OBJECTIVE@#To quantify the relationship between cerebral blood flow velocity and peripheral blood pressure during hypotension period, aiming to predict the brain hypotension before symptomatic occurrence.@*METHODS@#Twenty vasovagal syncope (VVS) patients who had a previous clinical history were selected in groups and 20 pair-matched control subjects underwent 70° tilt-up test. The subjects remained supine for 30 minutes before recordings when Doppler probes, electrodes and Finapres device were prepared. After continuous baseline recordings for 10 min, the subjects underwent head up tilt (HUT) test (70°), and were standing upright for 30 minutes or until syncope was imminent. For ethical reasons, the subjects were turned back to supine position immediately after SBP dropped to ≥20 mmHg, when their consciousness persisted. The point of syncope was synchronized for all the subjects by the point SBP reached the minima. Their beat-to-beat blood pressures (BP) were recorded continuously and bilateral middle cerebral artery (MCA) flow velocities were obtained with two 2 MHz Doppler probes from a transcranial Doppler ultrasonography (TCD) system. A nonlinear dynamic method--multimodal pressure flow (MMPF) analysis was introduced to access cerebral autoregulation during different time intervals. We introduced a new indicator--syncope index (SI), which was extracted from blood flow velocity (BFV) signal to evaluate the variation of cerebral vascular tension, and could reflect the deepness of dicrotic notch in BFV signal.@*RESULTS@#Compared with the syncope index of the baseline value at the beginning of the tilt test, SI in VVS group showed significantly lower when the VVS occurred (0.16±0.10 vs.0.27±0.10,P<0.01),while there was no significant difference in syncope index between the control group at the end of the tilt test and the baseline value at the beginning of the tilt test. For those VVS patients, pulse index and resistance index had no significant change. Syncope index decreased significantly 3 minutes before the point of syncope (0.23±0.07 vs.0.29±0.07,P<0.01).@*CONCLUSION@#Dynamic regulation is exhausted when vasovagal syncope occurred. Tension decrease of small vessels could have some relationship with loss of the cerebral autoregulation capability. The proposed syncope index could be a useful parameter in predicting syncope of VVS patients since it decreased significantly up to 3 minutes earlier from the point of syncope.

La prueba de inclinación (Tilt Test). 20 años de experiencia en el diagnóstico del Síncope neurocardiogénico Tilt Test: 20 years of experience in the diagnosis of the neurocardiogenic syncope / Tilt Test: 20 years of experience in the diagnosis of the neurocardiogenic syncope

Objetivo: Valorar los resultados de las pruebas de inclinación realizadas en un lapso de 2 décadas. Métodos: Este es un estudio observacional, descriptivo y retrospectivo. Se analizaron los resultados de las Pruebas de Inclinación (PI) realizadas entre 1997 y 2018 en forma consecutiva por una sola persona, inicialmente en el Hospital Clínica Bíblica, posteriormente en el Instituto del Corazón y finalmente en los últimos 17 años en el Centro Cardiológico Integral. Resultados: Se realizaron un total de 2705 pruebas entre los años de 1997 y el 2018. El 60% fue del sexo femenino. Se hicieron 245 pruebas a menores de 20 años (17.3%), 996 pruebas a personas entre 20 y 40 años (36.8%), 969 pruebas a pa cientes entre los 40 y 60 años (35.8%) y a 271 pacientes mayores de 60 años (10%). Del total de la muestra evaluada, 2316 pacientes presentaron un resultado positivo para alguna de los diferentes tipos de respuesta en la prueba de inclinación, equivalente al 85.6%, mientras que 389 pacientes obtuvieron un resultado negativo (respuesta normal), equivalente al 14.4%. En la mayor cantidad de pacientes la positividad de la prueba se presentó en la fase II, 72.7% (1683 pacientes), el 27.3% (633 pacientes) la manifestaron en la fase I. Se presentó una respuesta vasodepresora en 1120 pacientes (48.2%), respuesta mixta en 727 pacientes (31.3%), respuesta cardioinhibidora en 304 casos (13.1%). Además, 69 pacientes pre sentaron una respuesta sugestiva (2.9%) y 104 pacientes tuvieron otros tipos de respuestas (4.5%). De estos últimos, 48% correspondió al síndrome de taquicardia postural ortostática (POTS), 17% a incompetencia cronotrópica, 19% a hipoten sión ortostática y 16% a disautonomía. Un total de 43 pacientes (1,6%) presentaron hipersensibilidad del seno carotídeo. Conclusiones: La PI en nuestro medio tiene una adecuada sensibilidad en el diagnóstico del Síncope Neurocardiológico (SNCG) en los diferentes grupos de edad, es un método seguro, fácil de realizar y accesible a la mayoría de las personas que la requieran

Tilt Test: 20 years of experience in the diagnosis of the neurocardiogenic syncope Objective: To evaluate the results of the tilt tests carried out during 2 decades. Methods: This is an observational, descriptive and retrospective study. We analyzed the results of the tilt tests conducted between 1997 and 2018 consecutively by a single person, initially at the "Hospital Clínica Bíblica", later at the "Instituto del Corazón" and finally in the last 17 years at the "Centro Cardiológico Integral". Results: A total of 2705 tests were carried out between 1997 and 2018. Sixty percent were female. There were 245 tests for people under 20 years (17.3%), 996 tests for people between 20 and 40 years (36.8%), 969 tests for patients between 40 and 60 years (35.8%) and 271 patients older than 60 years (10%). Of the total sample evaluated, 2316 patients presented a positive result for some of the different types of response in the tilt test, equivalent to 85.6%, while 389 patients obtained a negative result (normal response), equivalent to 14.4%. In the largest number of patients, the positivity of the test was presented in phase II, 72.7% (1683 patients), and 27.3% (633 patients) manifested it in phase I. A vasodepressant response was presented in 1120 patients (48.2%), mixed response in 727 patients (31.3%), cardioinhibitory response in 304 cases(13.1%). In addition, 69 patients presented a suggestive response (2.9%) and 104 patients had other types of responses (4.5%). Of the latter, 48% corresponded to orthostatic postural tachycardia syndrome (POTS), 17% to chronotropic incompetence, 19% to orthostatic hypotension and 16% to dysautonomia. A total of 43 patients (1.6%) presented hypersensitivity of the carotid sinus. Conclusions: Tilt test in our environment has an adequate sensitivity in the diagnosis of the neurocardiogenic syncope in different age groups, it is a safe method, easy to perform and accessible to most people who require it.

Cardiac and Musculoskeletal Responses to the Effects of Passive and Active Tilt Test in Healthy Subjects / Respostas Cardíacas e Musculoesqueléticas aos Efeitos do Tilt Test Passivo e Ativo em Indivíduos Saudáveis

Abstract Background: Maintenance of orthostatism requires the interaction of autonomic and muscle responses for an efficient postural control, to minimize body motion and facilitate venous return in a common type of syncope called neurocardiogenic syncope (NCS). Muscle activity in standing position may be registered by surface electromyography, and body sway confirmed by displacement of the center of pressure (COP) on a force platform. These peripheral variables reflect the role of muscles in the maintenance of orthostatism during the active tilt test, which, compared with muscle activity during the passive test (head-up tilt test), enables the analyses of electromyographic activity of these muscles that may anticipate the clinical effects of CNS during these tests. Objective: to evaluate and compare the effects of a standardized protocol of active and passive tests for CNS diagnosis associated with the effects of Valsalva maneuver (VM). Methods: twenty-thee clinically stable female volunteers were recruited to undergo both tests. EMG electrodes were placed on muscles involved in postural maintenance. During the active test, subjects stood on a force platform. In addition to electromyography and the platform, heart rate was recorded during all tests. Three VMs were performed during the tests. Results: progressive peripheral changes were observed along both tests, more evidently during the active test. Conclusion: the active test detected changes in muscle and cardiovascular responses, which were exacerbated by the VM.

Resumo Fundamento: A manutenção do ortostatismo requer interação das respostas autonômicas e musculares para um controle postural eficiente e minimizar oscilações do corpo e facilitar o retorno venoso frente a um tipo comum de síncope chamada neurocardiogênica (SNC). A atividade da musculatura na posição de pé pode ser documentada por meio da eletromiografia de superfície (EMG) e as oscilações do corpo confirmadas pelo deslocamento do centro de pressão (CP) sobre uma plataforma de força. Estas variáveis periféricas mostram o papel muscular na manutenção do ortostatismo durante o tilt test ativo bem como esta atividade muscular ser comparada durante o teste passivo, Head-Up Tilt test, na tentativa de verificar alterações na atividade eletromiográfica destes músculos que podem antecipar os efeitos clínicos da SNC durante estes testes. Objetivo: Avaliar e comparar os efeitos de um protocolo padronizado para testes ativo e passivo de detecção da SNC associado ao efeito da manobra de valsalva (MV). Métodos: 23 voluntárias mulheres clinicamente saudáveis foram recrutadas para realizar ambos os testes. Os eletrodos da EMG foram posicionados em músculos associados com a manutenção postural, além de durante o teste ativo os sujeitos realizarem a postura ortostática sobre uma plataforma de força. Foi registrado além da EMG e da plataforma, a frequência cardíaca durante todo o teste. Três MV foram realizadas durante os testes. Resultados: Alterações periféricas foram verificadas de maneira progressiva ao longo dos testes, sendo mais evidente durante o teste ativo. Conclusão: o teste ativo verificou mudanças mais evidentes nas respostas musculares e cardiovasculares, amplificadas pela MV.

Patterns of Orthostatic Blood Pressure Changes in Patients with Orthostatic Hypotension

BACKGROUND AND PURPOSE: The objective of this study was to determine the patterns of blood pressure (BP) changes during the head-up tilt (HUT) test, particularly in terms of its clinical significance for patients with orthostatic hypotension (OH). METHODS: OH was divided into four categories based on systolic BP changes occurring within the first 10 minutes of the HUT test: sustained orthostatic hypotension (SOH), progressive orthostatic hypotension (POH), orthostatic hypotension with partial recovery (OHPR), and transient orthostatic hypotension (TOH). RESULTS: In total, 151 patients were analyzed: 65 with SOH, 38 with POH, 21 with OHPR, and 27 with TOH. POH patients exhibited the greatest reduction in systolic BP after HUT and were also the most likely to develop symptoms requiring early termination of the HUT test (42.1%, p < 0.001). Additionally, SOH patients exhibited smaller heart-rate variation with deep breathing values (p=0.003) and Valsalva ratios (p=0.022) compared to POH patients. The sweat volume was greatest in OHPR patients. CONCLUSIONS: Clinical characteristics, including the findings of autonomic function tests, differed between the OH patient groups. This might reflect differences in the underlying pathophysiologic mechanisms. Determining the patterns of BP changes during the HUT test may facilitate the development of effective management strategies in patients with OH.

Síncope único o muy poco frecuente en 104 casos / Single or very isolated syncope in 104 cases

Resumen Introducción: Es frecuente de encontrar personas enviadas para realizar la prueba de Tilt Test (TT), que sufrieron un solo síncope aislado o que ocurre muy ocasionalmente durante su vida. En este trabajo nos preguntamos en qué se diferencian estas personas de las que nunca tienen síncopes. Métodos: Realizamos el examen de TT en 104 pacientes que sufrieron sólo uno o como máximo 5 síncopes por cualquier causa durante su vida. Intentamos explicar cómo actúan los diferentes factores predisponentes para provocar el síncope. Resultados: Encontramos diferencias en factores predisponentes del síncope, entre nuestros pacientes y los controles en factores como: la herencia, la hipermovilidad articular, el encharcamiento venoso durante el TT, la ingesta de alimentos, el uso de fármacos, el estrés y la emoción. Conclusiones: En el síncope único o muy ocasional, deben conjugarse en la persona dos factores. Lo explicamos: Estos pacientes tienen una predisposición orgánica (herencia -hipermovilidad articular- falla en los baroreflejos, algunas enfermedades neurológicas, etc.) a presentar síncopes. Pero los síncopes no ocurrirán a menos que se agregue simultáneamente un factor ambiental, que actúa como un desencadenante (estadía larga de pie, estrés, dolor y emoción, deshidratación, drogas, comida abundante, etc.), es por eso que en estos pacientes los síncopes son tan raros.

Introduction: It is frequent meeting people sent to perform a tilt test suffering from a single or such isolated syncope that occur very occasionally during the patient's life. We ask ourselves how these people differ from those who never have syncopes. Methods: We performed tilt test in 104 patients who suffer a single or maximum 5 syncopes from any cause during their lifetimes. We try to explain how different predisposing factors act to provoke syncope. Results: We found differences between cases and controls in inheritance of syncopes, joint hypermobility, venous pooling during tilt test, food intake, use of drugs, stress and emotion as a trigger for syncope. Conclusions: Patients with single or occasional syncope have an organic predisposition (inheritance - joint hypermobility - failure in the baroreflexes, some neurological diseases, etc.) to present syncopes, but syncopes do not occur unless it is added simultaneously an environmental factor, which acts as a trigger (prolonged standing up - stress, pain and emotion - dehydration - drugs - abundant food, etc.) that is why these episodes are so rare.

Orthostatic Hypotension and Cognitive Function in Parkinson's Disease

BACKGROUND: Although orthostatic hypotension (OH) and cognitive impairment (CI) are common non-motor symptoms of Parkinson's disease (PD), the relationship between OH and CI remains to be clarified. This study was aimed to investigate the relationship between OH and CI in PD. METHODS: We recruited 192 patients who were diagnosed as PD based on the UK Brain Bank diagnostic criteria. The Hoehn & Yahr stages were ranged I to III and patients underwent extensive clinical evaluation, including brain magnetic resonance imaging (MRI) for cerebral white matter hyperintensity (WMH), tilt table test, the Korean version of Montreal Cognitive Assessments and the Korean version of Mini-Mental Status Examination in one month from the first clinic visit. The participants were divided into two groups according to the presence of OH (OH+ vs. OH−) and cognitive function (cognitive normal, CN vs. CI), respectively. RESULTS: Significant relationship between OH and cognitive function (p=0.04) was found in our patients. The patients with OH+ had higher risk of CI by 2.6 times than that of OH+ patients. Maximum heart rate change during tilt table test was correlated with cognitive function and white matter changes, whereas blood pressure change during tilt table test showed no correlation with those parameters. CONCLUSIONS: There was significant relationship between OH and CI in PD. Therefore, PD patients with either symptom may need periodic evaluation and proper management for OH and cognitive functions.

Evaluation of Adrenergic Function: Tilt-Table and Valsalva Test / 대한평형의학회지

Orthostatic dizziness is a common dizziness syndrome characterized by nonvertiginous lightheadedness when patients rise to stand from a sitting or supine position. Orthostatic dizziness is commonly believed to derive from orthostatic hypotension (OH) or postural tachycardia syndrome (POTS). Tilt-table test and Valsalva maneuver are standardized methods for evaluating of adrenergic autonomic function and essential for diagnosis of OH and POTS. We described the guidelines and interpretations of the tilt-table test and Valsalva maneuver.

Etiology and Clinical Characteristics of Pediatric Dizziness / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Dizziness is not uncommon in children. The etiology of dizziness varies according to different studies due to different methods of examination or characteristics of the dizziness center. To assess meaningful causes of dizziness in children, a multidisciplinary approach would be needed. The purpose of this study was to analyze the main pathologies associated with vertigo and dizziness in children, paying particular attention to recent diagnostic advances with a multidisciplinary approach. SUBJECTS AND METHOD: A total of 73 children, aged between 4-18 years, who visited the Pediatric Dizziness Clinic of the University Hospital from January 2016 to June 2016 were included in this study. Medical records were reviewed retrospectively. All of the subjects were examined by history, questionnaires, physical examinations, electrocardiogram, hematologic tests, brain MRI scan, audiogram and vestibular function tests. Patients who had orthostatic symptoms additionally underwent a tilt table test, and in selective cases, a caloric and vestibular evoked myogenic potential tests as well. RESULTS: Vestibular migraine (VM) and benign paroxysmal vertigo of childhood (BPVC) were found in 35.6% and 27.4% of the children with dizziness, respectively. The incidence of orthostatic hypotension and postural orthostatic tachycardia syndrome were 12.3% each, both of which are higher than other previous reports. Other causes were Meniere's disease, benign paroxysmal positional vertigo, vestibular neuritis and so on. CONCLUSION: VM and BPVC were the most common causes of pediatric dizziness. Also, the incidence of orthostatic dizziness was rather high in pediatric population. The evaluation of dizziness in children should include a thorough check of history (questionnaire), neurotological examination, vestibular function tests and a tilt table test.

Taquicardia ventricular polimórfica durante teste de inclinação na doença de Chagas / Polymorphic ventricular tachycardia during tilt testing in Chagas disease

Paciente do sexo masculino, de 62 anos de idade, com megacólon chagásico sem manifestações cardíacas, apresentou evento sincopal sem pródromos, sendo submetido a Holter de 24 horas, ecocardiografia, teste ergométrico e cineangiocoronariografia, que se mostraram normais. O estudo eletrofisiológico mostrou ausência de distúrbios de condução e de indução de taquiarritmias. Durante a fase basal do teste de inclinação, o paciente apresentou taquicardia ventricular polimórfica. Foi realizado implante de cardioversor-desfibrilador implantável. Na evolução, apresentou deterioração da função ventricular com início de terapêutica específica. Após sete anos de acompanhamento, observaram-se três episódios de taquicardia ventricular polimórfica adequadamente revertidos pelo cardioversor-desfibrilador implantável

A 62 year-old man with Chagasic megacolon without cardiac manifestations developed a syncope without prodrome and was submitted to 24-hour Holter monitoring, echocardiogram, exercise test and coronary angiography. Electrophysiology tests showed there was no conduction and tachyarrhythmia induction disorders. During the baseline phase of the tilt test, the patient presented a polymorphic ventricular tachycardia. An implantable cardioverter defibrillator was implanted. At the follow-up, the patient presented left ventricular deterioration and specific therapy was started. After seven years of follow-up, three episodes of polymorphic ventricular tachycardia were observed and were successfully converted

Cardiovascular Autonomic Dysfunction in Patients with Drug-Induced Parkinsonism

BACKGROUND AND PURPOSE: Recent studies have shown that several nonmotor symptoms differ between Parkinson's disease (PD) and drug-induced parkinsonism (DIP). However, there have been no reports on cardiovascular autonomic function in DIP, and so this study investigated whether cardiovascular autonomic function differs between PD and DIP patients. METHODS: This study consecutively enrolled 20 DIP patients, 99 drug-naïve PD patients, and 25 age-matched healthy controls who underwent head-up tilt-table testing and 24-h ambulatory blood pressure monitoring. RESULTS: Orthostatic hypotension was more frequent in patients with PD or DIP than in healthy controls. In DIP, orthostatic hypotension was associated with the underlying psychiatric diseases and neuroleptics use, whereas prokinetics were not related to orthostatic hypotension. The supine blood pressure, nighttime blood pressure, and nocturnal blood pressure dipping did not differ significantly between the DIP and control groups. Supine hypertension and nocturnal hypertension were more frequent in PD patients than in controls. CONCLUSIONS: The included DIP patients frequently exhibited orthostatic hypotension that was associated with the underlying diseases as well as the nature of and exposure time to the offending drugs. Clinicians should individualize the manifestations of DIP according to underlying diseases as well as the action mechanism of and exposure time to each offending drug.