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1.
Eur Arch Otorhinolaryngol ; 279(12): 5939-5943, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35916924

RESUMO

INTRODUCTION: Flexible endoscopic procedures (FEP) using a working channel allowed otolaryngologists to perform more procedures on the pharynx and the larynx under local anesthesia. The purpose of this work is to demonstrate the feasibility and safety of this technique by studying the adverse effects of this practice in an office-based setting. METHODS: This is a monocentric retrospective cohort study. We searched the database using the French procedural code for FEP performed in an outpatient setting between January 2005 and December 2020. Data regarding the patient's characteristics, indications, and periprocedural complications were extracted. RESULTS: In total, we included 231 patients with a total of 308 FEP: 36% biopsy, 20% hyaluronic acid injection (including 3.5% at the level of the cavum), 20% injection of other substances (in descending order: botulinum toxin, cidofovir, physiological serum, cortisone), 20% exploration for an occult tumor, 3% samples for microbiological analysis, 1% other procedures. Of the 308 FEP included in this study, 24 patients (10.3%) had complications corresponding to 7.8% of the procedures performed. During the procedures, reported complications include minor laryngeal bleeding (n = 5), vasovagal syncope (n = 5), laryngospasm (n = 1) or nausea (n = 3), dysphagia (n = 3), and voice disorders (n = 3). Post-procedural complications were hypertensive crisis (n = 1), asthma attack (n = 1), pneumonia (n = 1), laryngitis (n = 1). Using the Clavien-Dindo classification system, these complications could be defined as grade I (laryngeal bleeding, vasovagal syncope, laryngospasm, dysphagia, nausea, voice disorders, and laryngitis) and grade II (hypertensive crisis, asthma attack, pneumonia) in 9.1% and 1.2% of cases, respectively. Most of these complications were self-limiting, while asthma attacks, pneumonia, laryngitis, and voice disorders required a medical intervention. All complications were managed without sequelae. There was no serious complication grade (no grade III, IV or V). CONCLUSIONS: FEP, which is now well standardized in our institution, makes it possible to carry out a wide range of interventions with little morbidity. These results are in line with those of literature but this technique remains out of nomenclature in France. Our experience led to the development of an evidence-based standard of care that can serve as a framework for practitioners on a nationwide level, while the work to establish official guidelines by the French society of phoniatrics and laryngology is in progress.


Assuntos
Asma , Transtornos de Deglutição , Laringismo , Laringite , Laringe , Síncope Vasovagal , Distúrbios da Voz , Humanos , Anestesia Local , Faringe , Estudos Retrospectivos , Laringite/patologia , Laringismo/etiologia , Laringismo/patologia , Síncope Vasovagal/patologia , Laringe/patologia , Distúrbios da Voz/patologia , Náusea/patologia
2.
Turk J Pediatr ; 61(1): 52-58, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31559722

RESUMO

Lin J, Zhao H, Ma L, Jiao F. Body mass index is decreased in children and adolescents with postural tachycardia syndrome. Turk J Pediatr 2019; 61: 52-58. Our intent was to explore the predictive value of body mass index (BMI) in differentiating between vasovagal syncope (VVS) and postural tachycardia syndrome (POTS) in children and adolescents. A total of 111 children and adolescents with POTS and 154 children and adolescents with VVS were included in our study. The control group included 82 healthy children and adolescents. Height and weight were measured in all participants. The headup tilt test was performed in participants in all groups (POTS, VVS, and control). BMI was significantly lower in children and adolescents with POTS (18.3±3.4) than in children and adolescents with VVS (20.3±4.2) and the control group (20.5±2.9). The receiver operating characteristic curve was performed to determine the predictive value of BMI differentiation between POTS and VVS and showed that a BMI of 19.30 was the cutoff value for the probability of distinction. However, the results (BMI of 19.30) produced unsatisfactory sensitivity (57.1%) and specificity (28.8%) rates of correctly discriminating between patients with POTS and patients with VVS. Children and adolescents with POTS have a lower BMI compared with healthy peers or children and adolescents with VVS.


Assuntos
Índice de Massa Corporal , Síndrome da Taquicardia Postural Ortostática/diagnóstico , Síncope Vasovagal/diagnóstico , Adolescente , Estudos de Casos e Controles , Criança , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Síndrome da Taquicardia Postural Ortostática/patologia , Síndrome da Taquicardia Postural Ortostática/fisiopatologia , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade , Síncope Vasovagal/patologia , Síncope Vasovagal/fisiopatologia , Teste da Mesa Inclinada
3.
Diabetes Res Clin Pract ; 151: 152-162, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31004672

RESUMO

STUDY HYPOTHESIS: Cardiac autonomic dysfunction might lead to higher vaso vagal syncope (VVS) recurrence rate in type 2 diabetes mellitus (T2DM) patients vs. non diabetics patients. BACKGROUND: VVS recurrence might be due to alterations of autonomic system function, as assessed by heart rate variability (HRV). To date, in this study we investigated the correlation between HRV alterations and VVS recurrence at 12 months of follow up in T2DM vs. non T2DM patients. MATERIALS AND METHODS: In a prospective multicenter study we studied a propensity score matching (PSM) analysis of 121 T2DM vs. 121 non T2DM patients affected by VVS. RESULTS: T2DM vs. non T2DM patients had at baseline a higher rate of HRV dysfunction, and this was linked to higher rate of VVS recurrence at 12 months of follow up (p < 0.05). Blood pressure alterations and lower LF/HF ratio were linked to higher rate of all cause syncope recurrence, and of vasodepressor, cardio inhibitory, and mixed syncope recurrence (p < 0.05). Anti hypertensive drug therapies increased the number of vasodepressor and mixed syncope events (p < 0.05); alterations of heart rate increased syncope recurrence and mixed syncope recurrence events (p < 0.05). Finally, T2DM was linked to higher rate of VVS recurrence, and specifically of vasodepressor and mixed VVS recurrence (p < 0.05). CONCLUSIONS: T2DM patients have alterations of the autonomic nervous system, as result of cardiac autonomic neuropathy. However, T2DM diagnosis and autonomic dysfunction assessed by HRV alterations predicted VVS recurrence.


Assuntos
Diabetes Mellitus Tipo 2/complicações , Cardiopatias/complicações , Síncope Vasovagal/etiologia , Teste da Mesa Inclinada/métodos , Diabetes Mellitus Tipo 2/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Síncope Vasovagal/patologia
4.
Circulation ; 136(5): e123-e135, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28280230

RESUMO

OBJECTIVES: To determine, using systematic review of the biomedical literature, whether pacing reduces risk of recurrent syncope and relevant clinical outcomes among adult patients with reflex-mediated syncope. METHODS: MEDLINE (through PubMed), EMBASE, and the Cochrane Central Register of Controlled Trials (through October 7, 2015) were searched for randomized trials and observational studies examining pacing and syncope, and the bibliographies of known systematic reviews were also examined. Studies were rejected for poor-quality study methods and for the lack of the population, intervention, comparator, or outcome(s) of interest. RESULTS: Of 3188 citations reviewed, 10 studies met the inclusion criteria for systematic review, including a total of 676 patients. These included 9 randomized trials and 1 observational study. Of the 10 studies, 4 addressed patients with carotid sinus hypersensitivity, and the remaining 6 addressed vasovagal syncope. Among the 6 open-label (unblinded) studies, we found that pacing was associated with a 70% reduction in recurrent syncope (relative risk [RR]: 0.30; 95% confidence interval [CI]: 0.15-0.60). When the 2 analyzable studies with double-blinded methodology were considered separately, there was no clear benefit (RR: 0.73; 95% CI: 0.25-2.1), but confidence intervals were wide. The strongest evidence was from the randomized, double-blinded ISSUE-3 (Third International Study on Syncope of Uncertain Etiology) trial, which demonstrated a benefit of pacing among patients with recurrent syncope and asystole documented by implantable loop recorder. CONCLUSIONS: There are limited data with substantive evidence of outcome ascertainment bias, and only 2 studies with a double-blinded study design have been conducted. The evidence does not support the use of pacing for reflex-mediated syncope beyond patients with recurrent vasovagal syncope and asystole documented by implantable loop recorder.


Assuntos
Reflexo , Síncope/terapia , American Heart Association , Humanos , Marca-Passo Artificial , Guias de Prática Clínica como Assunto , Síncope/patologia , Síncope Vasovagal/patologia , Síncope Vasovagal/terapia , Estados Unidos
5.
Vox Sang ; 111(2): 135-43, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27167612

RESUMO

BACKGROUND AND OBJECTIVES: Vein visualization technology (VVT) devices use near-infrared light to assist location of peripheral veins. The current study investigated the impact of VVT on donor experience and collection success for young blood donors at the Australian Red Cross Blood Service. MATERIALS AND METHODS: The study in donors aged 18 to 30 years used a two intervention to one control randomized trial design with 285 new and 587 returning donors recruited at two sites. Donors reported presyncopal symptoms, phlebotomy pain, anxiety and intentions to redonate along with other measures. Participating phlebotomists rated usefulness of the technology. Flow rates, collection volumes and other donation information were taken from routine data. RESULTS: No significant differences were found between control and intervention groups on presyncopal symptoms, phlebotomy pain, anxiety, intentions to redonate, flow rates, collection volumes or vasovagal reactions (all P's > 0·05). Phlebotomist ratings of VVT were significantly more positive when they had less than 5 years of experience (P < 0·01) or when the vein was not visible to the naked eye (P < 0·01). CONCLUSIONS: Results suggest that VVT does not improve the donation experience for younger blood donors. Staff reports indicate that VVT may have some utility for assisting with difficult phlebotomies.


Assuntos
Ansiedade , Doadores de Sangue/psicologia , Intenção , Síncope Vasovagal/patologia , Adolescente , Adulto , Austrália , Feminino , Humanos , Raios Infravermelhos , Masculino , Dor/etiologia , Flebotomia , Adulto Jovem
6.
Brain Dev ; 38(6): 609-12, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26740075

RESUMO

A 3-year-old boy with a dorsally exophytic tumor arising from the rostral medulla presented with a chief complaint of a change in his emotional behavior, most notably anxiety and paroxysmal crying often followed by syncope. Magnetic resonance imaging revealed that the tumor pushed on the dorsal surface of the medulla and displaced the medulla anteriorly, and also displaced the cerebellar vermis upward and slightly posteriorly. Tissue from a partial resection was diagnosed as a pilocytic astrocytoma. The symptoms did not improved after surgery, but did improve clinically after chemotherapy with vincristine and carboplatin, at which time MR showed a reduction in tumor size. We diagnosed the paroxysmal crying as 'pathological crying' and the syncope with increased anxiety as 'emotional vasovagal syncope'. This case stresses the importance of recognition of this rare presentation as an indication of a medullary tumor.


Assuntos
Astrocitoma/diagnóstico , Neoplasias do Tronco Encefálico/diagnóstico , Choro , Síncope Vasovagal/diagnóstico , Astrocitoma/patologia , Astrocitoma/fisiopatologia , Astrocitoma/terapia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiopatologia , Neoplasias do Tronco Encefálico/patologia , Neoplasias do Tronco Encefálico/fisiopatologia , Neoplasias do Tronco Encefálico/terapia , Pré-Escolar , Terapia Combinada , Choro/fisiologia , Diagnóstico Diferencial , Eletroencefalografia , Humanos , Imageamento por Ressonância Magnética , Masculino , Síncope Vasovagal/patologia , Síncope Vasovagal/fisiopatologia , Síncope Vasovagal/terapia
7.
PLoS One ; 10(4): e0120788, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25860977

RESUMO

The objective of this study was to clarify the effects of disease on neurally mediated syncope (NMS) during an acute stress reaction. We analyzed the mechanism of the molecular interaction and the polymorphisms of the alpha-2 adrenoreceptor (α2B-AR) gene as the potential psychiatric cause of incentive stress. We focused on the following three genotypes of the repeat polymorphism site at Glu 301-303 in the α2B-AR gene: Glu12/12, Glu12/9, and Glu9/9. On the basis of our clinical research, NMS is likely to occur in people with the Glu12/9 heterotype. To verify this, we assessed this relationship with the interaction of Gi protein and adenylate cyclase by in silico analysis of the Glu12/9 heterotype. By measuring the difference in the dissociation time of the Gi-α subunit twice, we found that the Glu12/9 heterotype suppressed the action of adenylate cyclase longer than the Glu homotypes. As this difference in the Glu repeat number effect is thought to be one of the causes of NMS, we investigated the evolutionary significance of the Glu repeat number. Glu8 was originally repeated in simians, while the Glu12 repeats occurred over time during the evolution of bipedalism in humans. Taken with the Glu12 numbers, NMS would likely become a defensive measure to prevent significant blood flow to the human brain.


Assuntos
Receptores Adrenérgicos alfa 2/genética , Síncope Vasovagal/patologia , Alelos , Animais , Sequência de Bases , DNA/análise , DNA/isolamento & purificação , DNA Mitocondrial/análise , DNA Mitocondrial/classificação , Epinefrina/sangue , Evolução Molecular , Feminino , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Frequência do Gene , Genótipo , Humanos , Masculino , Norepinefrina/sangue , Filogenia , Polimorfismo de Nucleotídeo Único , Primatas/genética , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Receptores Adrenérgicos alfa 2/química , Receptores Adrenérgicos alfa 2/metabolismo , Síncope Vasovagal/metabolismo , Termodinâmica
8.
Chin Med J (Engl) ; 127(21): 3690-4, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25382320

RESUMO

BACKGROUND: Orthostatic intolerance (OI) is a common disease at pediatric period which has a serious impact on physical and mental health of children. The purpose of this study was to investigate the effect of related factors on the prognosis of children with OI. METHODS: The subjects were 170 children with OI, including 71 males (41.8%) and 99 females (58.2%) with age from 6 to 17 (12.0±2.6) years. The effect of related factors on the prognosis of children was studied by using univariate analysis. Then, the impact of children's age, symptom score, duration, disease subtype, and treatment on patient's prognosis was studied via analysis of COX proportional conversion model. RESULTS: Among 170 cases, 48 were diagnosed with vasovagal syncope, including 28 cases of vasoinhibitory type, 16 cases of mixed type, and 4 cases of cardioinhibitory type; 115 cases were diagnosed with postural tachycardia syndrome and 7 cases with orthostatic hypotension. By using univariate analysis of Cox regression, the results showed that symptom score had a marked impact on the time of symptoms improvement of children after taking medication (P < 0.05), while other univariates had no impact (P > 0.05). Multivariate analysis using Cox proportional hazards regression model showed that the symptom score at diagnosis had a significant effect on holding time of symptoms improvement of children after taking medication (P < 0.05). Kaplan-Meier curve showed that symptom-free survival was higher in children with symptom score equal to 1 than children with symptom score equal to or greater than 2 during follow-up (P < 0.05). CONCLUSION: Symptom score is an important factor affecting the time of symptom improvement after treatment for children with OI.


Assuntos
Intolerância Ortostática/diagnóstico , Adolescente , Criança , Feminino , Humanos , Masculino , Metoprolol/uso terapêutico , Midodrina/uso terapêutico , Intolerância Ortostática/tratamento farmacológico , Intolerância Ortostática/mortalidade , Intolerância Ortostática/patologia , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Águas Salinas/uso terapêutico , Síncope Vasovagal/diagnóstico , Síncope Vasovagal/tratamento farmacológico , Síncope Vasovagal/mortalidade , Síncope Vasovagal/patologia
9.
Clin Interv Aging ; 9: 333-8, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24600213

RESUMO

BACKGROUND: The incidence of syncope increases in individuals over the age of 70 years, but data about this condition in the elderly are limited. Little is known about tilt testing (TT), carotid sinus massage (CSM), or supine and upright blood pressure measurement related to age or about patients with complex diagnoses, for example, those with a double diagnosis, ie, positivity in two of these three tests. METHODS: A total of 873 consecutive patients of mean age 66.5±18 years underwent TT, CSM, and blood pressure measurement in the supine and upright positions according to the European Society of Cardiology guidelines on syncope.1 Neuroautonomic evaluation was performed if the first-line evaluation (clinical history, physical examination, electrocardiogram) was suggestive of neurally mediated syncope, or if the first-line evaluation was suggestive of cardiac syncope but this diagnosis was excluded after specific diagnostic tests according to European Society of Cardiology guidelines on syncope, or if certain or suspected diagnostic criteria were not present after the first-line evaluation. RESULTS: A diagnosis was reached in 64.3% of cases. TT was diagnostic in 50.4% of cases, CSM was diagnostic in 11.8% of cases, and orthostatic hypotension was present in 19.9% of cases. Predictors of a positive tilt test were prodromal symptoms and typical situational syncope. Increased age and a pathologic electrocardiogram were predictors of carotid sinus syndrome. Varicose veins and alpha-receptor blockers, nitrates, and benzodiazepines were associated with orthostatic hypotension. Twenty-three percent of the patients had a complex diagnosis. The most frequent association was between vasovagal syncope and orthostatic hypotension (15.8%); 42.9% of patients aged 80 years or older had a complex diagnosis, for which age was the strongest predictor. CONCLUSION: Neuroautonomic evaluation is useful in older patients with unexplained syncope after the initial evaluation. A complex neurally mediated diagnosis is frequent in older people. Our results suggest that complete neuroautonomic evaluation should be done particularly in older patients.


Assuntos
Síncope/diagnóstico , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Protocolos Clínicos , Eletrocardiografia , Feminino , Coração/inervação , Coração/fisiopatologia , Humanos , Masculino , Síncope/etiologia , Síncope/patologia , Síncope Vasovagal/diagnóstico , Síncope Vasovagal/patologia , Teste da Mesa Inclinada
10.
AJNR Am J Neuroradiol ; 35(1): 113-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23828108

RESUMO

BACKGROUND AND PURPOSE: Alterations in the central autonomic network are hypothesized to play a role in the pathophysiologic mechanism underlying neurocardiogenic syncope; however, few data are available regarding the structural changes of the brain in this condition. We used voxel-based morphometry and regional volumetry to identify possible neuroanatomic correlates. MATERIALS AND METHODS: We prospectively studied 32 patients with neurocardiogenic syncope with a positive response to the head-up tilt test and 32 controls who had no history of syncope. We used voxel-based morphometry to compare GM volumes between patients and controls. In addition, regional volumes of structures known to be included in the central autonomic network were measured and compared between the groups. Correlation analyses were also performed between clinical variables and anatomic data. RESULTS: Voxel-based morphometry showed a significant GM volume reduction in the right insular cortex in patients with neurocardiogenic syncope compared with controls (corrected P = .033). Regional volumetry showed a significant reduction of right insular volumes in patients compared with controls (P = .002, MANCOVA). Smaller right insular volumes in patients with neurocardiogenic syncope were related to larger drops in systolic (P = .020) and diastolic (P = .003) blood pressures during the head-up tilt test. CONCLUSIONS: We observed a novel finding of right insular atrophy in patients with neurocardiogenic syncope with a positive response to the head-up tilt test, implicating the role of right insular dysfunction in the pathophysiologic mechanism underlying neurocardiogenic syncope. Our findings further support the hypothesis that right insular dysfunction may cause a decrease in sympathetic activity and a reciprocal increase in parasympathetic activity, leading to syncope.


Assuntos
Córtex Cerebral/patologia , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Imageamento por Ressonância Magnética/métodos , Neurônios/patologia , Síncope Vasovagal/patologia , Adolescente , Adulto , Atrofia/patologia , Criança , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto Jovem
11.
Kardiologiia ; 51(3): 74-80, 2011.
Artigo em Russo | MEDLINE | ID: mdl-21627618

RESUMO

Vasovagal syncope and carotid sinus syndrome are common conditions in young and elderly people, respectively, mostly with benign prognosis. Nevertheless, severe or "malignant" syncopal attacks in some patients may be associated with life-threatening injury. Unfortunately, up to now almost all drug trials have failed to demonstrate any benefit in preventing syncope and interventional approach (pacemaker) may be appropriate. This article contains literature review and discussion of indications for pacing in vasovagal syncope and carotid sinus syndrome.


Assuntos
Estimulação Cardíaca Artificial , Seio Carotídeo , Marca-Passo Artificial/normas , Seleção de Pacientes , Síncope Vasovagal , Barorreflexo/efeitos dos fármacos , Estimulação Cardíaca Artificial/métodos , Estimulação Cardíaca Artificial/normas , Fármacos Cardiovasculares/uso terapêutico , Seio Carotídeo/efeitos dos fármacos , Seio Carotídeo/patologia , Seio Carotídeo/fisiopatologia , Humanos , Pressorreceptores/patologia , Pressorreceptores/fisiopatologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Recidiva , Síncope Vasovagal/etiologia , Síncope Vasovagal/patologia , Síncope Vasovagal/fisiopatologia , Síncope Vasovagal/terapia , Falha de Tratamento
12.
Int J Cardiol ; 142(1): 38-43, 2010 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-19176256

RESUMO

BACKGROUND: During the development of neurocardiogenic syncope (NCS) postural dependant venous blood pooling sets off a cascade of autonomic reflexes. This causes an initial rise in sympathetic tone, which is followed by an overshoot parasympathetic activation resulting in systemic vasodilatation and/or sinus bradycardia. However, other factors like associated hyperventilation or changes in blood gas content may also contribute to syncope. Hyperoxic cardiac chemoreflex sensitivity (CHRS) is an autonomic functional test that describes the heart rate decrease in response to increases in blood oxygen content. The purpose of this study was to investigate whether CHRS is altered in NCS. METHODS AND RESULTS: CHRS was compared in 16 NCS patients (49+/-4 yr old) vs. 16 age and gender matched controls (53+/-2 yr old). NCS was verified by clinical syncope and positive head-up tilt testing. The hyperoxic CHRS was measured by determination of the venous partial pressure of oxygen and heart rate before and after 5 min of pure oxygen inhalation. The difference of the R-R intervals before and after oxygen inhalation divided by the difference in the oxygen pressures were calculated as hyperoxic chemoreflex sensitivity [ms/mm Hg]. CHRS in the control group was 7.1+/-1.1 ms/mm Hg. By contrast, CHRS in NCS patients was significantly lower (2.8+/-1.0 ms/mm Hg; p<0.05). CONCLUSION: Neurocardiogenic syncope is associated with decreased hyperoxic cardiac chemoreflex sensitivity possibly reflecting impaired deactivation of arterial chemoreceptors. The clinical and pathophysiologic importance of chemosensor function in neurocardiogenic syncope needs to be investigated in more detail.


Assuntos
Células Quimiorreceptoras/fisiologia , Hiperóxia/diagnóstico , Hiperóxia/fisiopatologia , Síncope Vasovagal/diagnóstico , Síncope Vasovagal/fisiopatologia , Células Quimiorreceptoras/patologia , Feminino , Humanos , Hiperóxia/patologia , Masculino , Pessoa de Meia-Idade , Síncope Vasovagal/patologia , Teste da Mesa Inclinada/métodos
14.
Prog Cardiovasc Dis ; 50(1): 49-80, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17631437

RESUMO

Whatever the pathogenesis of syncope is, the ultimate common cause leading to loss of consciousness is insufficient cerebral perfusion with a critical reduction of blood flow to the reticular activating system. Brain circulation has an autoregulation system that keeps cerebral blood flow constant over a wide range of systemic blood pressures. Normally, if blood pressure decreases, autoregulation reacts with a reduction in cerebral vascular resistance, in an attempt to prevent cerebral hypoperfusion. However, in some cases, particularly in neurally mediated syncope, it can also be harmful, being actively implicated in a paradox reflex that induces an increase in cerebrovascular resistance and contributes to the critical reduction of cerebral blood flow. This review outlines the anatomic structures involved in cerebral autoregulation, its mechanisms, in normal and pathologic conditions, and the noninvasive neuroimaging techniques used in the study of cerebral circulation and autoregulation. An emphasis is placed on the description of autoregulation pathophysiology in orthostatic and neurally mediated syncope.


Assuntos
Doenças Cardiovasculares/complicações , Artérias Cerebrais/fisiopatologia , Circulação Cerebrovascular , Síncope/fisiopatologia , Animais , Sistema Nervoso Autônomo/fisiopatologia , Doenças Cardiovasculares/patologia , Doenças Cardiovasculares/fisiopatologia , Artérias Cerebrais/inervação , Artérias Cerebrais/patologia , Circulação Colateral , Diagnóstico por Imagem/métodos , Homeostase , Humanos , Síncope/etiologia , Síncope/patologia , Síncope Vasovagal/patologia , Síncope Vasovagal/fisiopatologia
15.
Curr Opin Pediatr ; 16(4): 350-6, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15273492

RESUMO

PURPOSE OF REVIEW: Syncope is a common symptom in adolescents. The vast majority of cases are the result of benign neurocardiogenic syncope, without associated risk of sudden death. This paper reviews the mainstays of diagnosis and treatment for syncopal episodes, differentiation of syncope from life-threatening arrhythmia and aborted sudden cardiac death, and the patient populations at highest risk for cardiac symptoms and cardiac disease. RECENT FINDINGS: A detailed history (including past medical history and family history that focus on cardiac disease) combined with dynamic physical examination and electrocardiogram identifies the vast majority of adolescents with significant heart disease. Further diagnostic modalities have limited utility. Reassurance and supportive measures remain the treatment of choice, although drug therapy can sometimes be helpful, even if data are limited. Divergent approaches to the screening of the young competitive athlete exist. Particular attention is required in adolescents and young adults with exercise-associated syncope, eating disorders, chronic fatigue syndrome, or history of congenital heart disease. Their symptoms may be either more serious or challenging to manage. SUMMARY: Syncope in the adolescent patient is very common; true cardiac disease is not. The traditional diagnostic screen of history and physical combined with an electrocardiogram will identify the overwhelming majority of patients with significant disease. Patients with abnormalities on this initial office evaluation, history of cardiac disease, or complicating medical illness may benefit from referral to a cardiologist. Even within this patient subset, many will prove to have benign disease.


Assuntos
Síncope/diagnóstico , Adolescente , Cardiomiopatia Hipertrófica/complicações , Morte Súbita Cardíaca/etiologia , Transtornos da Alimentação e da Ingestão de Alimentos/complicações , Coração/fisiopatologia , Cardiopatias Congênitas/complicações , Humanos , Síndrome do QT Longo/complicações , Síncope/enfermagem , Síncope/fisiopatologia , Síncope Vasovagal/diagnóstico , Síncope Vasovagal/enfermagem , Síncope Vasovagal/patologia , Síncope Vasovagal/fisiopatologia
16.
J Electrocardiol ; 35(4): 303-6, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12395356

RESUMO

Fluid shifts in vasovagal syncope may be reflected in electrocardiographic P-wave duration. We examined the effect of head-upright tilt-table testing (HUT) on P-wave duration among patients with positive or negative HUT. P-wave duration was measured at baseline and several post-HUT time points. In patients with a positive HUT, the test was immediately discontinued. P-wave duration measurements obtained at the completion of the test or when symptoms occurred were compared to baseline measurements. The P-wave duration among patients with a positive HUT was significantly reduced at the onset of symptoms as compared to baseline (-14.0 ms, P = .0054) and 2-minute tilt measurements (-11.3 ms, P = .0246). P-wave duration measurements were not reduced in patients experiencing a negative HUT at any follow-up time. We showed a significant reduction in P-wave duration among patients experiencing positive HUT that suggests a dynamic relationship between atrial volume and P-wave duration.


Assuntos
Síncope Vasovagal/diagnóstico , Teste da Mesa Inclinada , Adulto , Idoso , Eletrocardiografia , Feminino , Sistema de Condução Cardíaco/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Síncope Vasovagal/patologia , Fatores de Tempo
17.
Phys Med Biol ; 45(11): 3403-12, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11098913

RESUMO

Entropy measures of RR interval variability during daily activity over a 24h period were compared in 30 patients with a positive head-up tilt (HUT) test and 30 patients with a negative HUT test who had a history of alleged neurocardiogenic syncope. Two different entropies, approximate entropy (ApEn) and entropy of symbolic dynamics (SymEn), were employed. In patients showing a positive HUT test, the entropies were significantly decreased when compared with the patients with a negative HUT test. In addition, SymEn in the patients with a negative HUT test was significantly lower than in the normal controls. Discriminant analysis using SymEn could correctly identify 89.3% (520/582) of the 1 h RR interval data of the patients with a positive HUT test regardless of the time of day. Baseline entropies of heart rate dynamics during daily activity were found to be significantly lower in patients with alleged neurocardiogenic syncope and a positive HUT test than in those with the same history but with a negative HUT test. The decreased entropy of symbolic heart rate dynamics may be of predictive value of a positive HUT test in patients with alleged neurocardiogenic syncope.


Assuntos
Entropia , Frequência Cardíaca , Síncope Vasovagal/patologia , Adulto , Estudos de Casos e Controles , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Fatores de Tempo
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