ABSTRACT
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.
Subject(s)
Humans , Male , Female , Adult , Young Adult , Receptors, Adrenergic, beta/genetics , Tilt-Table Test , Syncope, Vasovagal/diagnosis , Polymorphism, Genetic , Syncope, Vasovagal/genetics , GenotypeABSTRACT
Objective To evaluate diagnostic value of head upright tilt testing (HUTT) on orthostatic hypotension (OH) in patients with senile hypertension,and explore its efficacy and safety.Methods One hundred and sixty-six patients with senile hypertension were selected,and the patients were divided into 2 groups according to HUTT:experiment group (completed HUTT,86 cases) and control group (unfinished HUTT,80 cases).The blood pressure change was observed.The detection rate of OH and incidence of unexpected event were compared between 2 groups.Results The detection rate of OH in experiment group was 31.4％ (27/86),in control group was 17.5％ (14/80),and there was statistical difference (P ＜ 0.05).The incidence of unexpected event in experiment group was 0,in control group was 6.2％ (5/80),including 3 patients with dizziness amaurosis,unstable presyncope symptoms and fall,and 2 cases with syncope and sudden fall.There was statistical difference in incidence of unexpected event between 2 groups (P ＜ 0.05).Conclusions The use of HUTT in patients with senile hypertension can significantly improve the detection rate of OH,but also significantly reduce the incidence of unexpected event.The method is safe,effective,worthy of clinical promotion.
ABSTRACT
Head-up tilt test (HUTT) is an important method of diagnosing the syncope in children.It includes baseline HUTT (BHUTT),and sublingual nitroglycerin-provocated HUTT (SNHUTT).Physiological monitor is used to monitor the heart rate and blood pressure changes.At the same time,clinical pictures are recorded.According to clinical manifestations,heart rate and blood pressure of the children in HUTT,the corresponding symptoms including vasovagal syncope,postural orthostatic tachycardia syndrome and orthostatic hypotension can be diagnosed.During the test,it is necessary to monitor the hemodynamic changes and the informed consent should be obtained from parents.
ABSTRACT
PURPOSE--In order to identify neurally mediated syncope, head-up tilt testing was performed in patients with recurrent unexplained syncope. METHODS--The tests were performed in 125 patients in the fasting state, between 8:30 and 11:30 a.m. The blood pressure and heart rate were continuously monitored during 20 minutes in the resting state, and then, positioned at 60 degrees angle, for up to 40 minutes. A group of 20 patients with first negative test was submitted to intravenous isoproterenol in bolus of 2 micrograms every 2 minutes until symptoms occur or at a total dose of 8 micrograms. The test was considered positive when systolic blood pressure decreased at least 30 mmHg and the patient experimented syncope or pre-syncope. RESULTS--In 52 patients the test was positive (41.6 per cent ), 63.5 per cent of which had hypotension exclusively; 7.7 per cent asystole; and 28.8 per cent had hypotension and bradycardia. Nine of the 20 patients submitted to isoproterenol test were positive (45 per cent ). All patients recovered spontaneously after returning to supine position. CONCLUSION--Head-up tilt testing is a safe and effective method for the identification of neurally mediated syncope
Objetivo - Identificar a possível etiologia neuralmente mediada, em portadores de síncope de origem indeterminada (SOI) submetidos ao teste de inclinação. Métodos - Cento e vinte e cinco portadores de SOI foram submetidos, entre abril de 1991 a outubro de 1992, ao teste de inclinação, realizado pela manhã, em jejum, com período de repouso de 20min em decúbito horizontal e 40min a 60o, com monitorização contínua da pressão arterial (PA) e da freqüência cardíaca (FC). O teste sensibilizado consistiu na administração de isoproterenol em doses de 2µg a cada 2min a 60o , até a dose máxima de 8µg ou até o aparecimento de sintomas présincopais ou síncope e foi aplicado em um grupo de 20 pacientes nos quais o 1º teste havia sido negativo. O critério de positividade foi a queda sintomática da pressão arterial sistólica maior que 30mmHg. Resultados - Cinqüenta e dois (41,6%) indivíduos apresentaram testes positivos, dos quais 63,5% apresentaram resposta exclusivamente vasodepressora (queda da PA sem modificação da FC), 7,7% cardio-inibitória (assistolia) e 28,8% resposta mista. Dos 20 pacientes submetidos ao teste sensibilizado, 9 (45%) apresentaram resultados positivos. Todos recuperaram-se espontaneamente com o retorno para o decúbito horizontal. Conclusão - O teste de inclinação é um método eficiente e seguro na identificação da etiologia neurocardiogênica das síncopes até então de origem indeterminada