Head-up tilt test is useful for exploring neurally mediated syncope. Adenosine is an ATP derivative implicated in cardiovascular disturbances that occur during head-up tilt test. The aim of the present study was to investigate the impact of hyperoxia on adenosine plasma level and on hemodynamic changes induced by head-up tilt testing.Seventeen healthy male volunteers (mean age 35 ± 11 years) we...

Aim: We aimed to detect the utility of head up tilt test with video electroencephalography (EEG) in children with unexplained, recurrent loss of consciousness episodes. Method: Video EEG were recorded during the head up tilt test. The test was terminated if syncope or presyncope with 30% decrease in heart rate and/or systolic blood pressure occurred. Regarding encephalography, average amplitude...

PURPOSE Some patients with neurally mediated reflex syncope may be misdiagnosed as epilepsy because myoclonic jerky movements are observed during syncope. The seizure-like activities during the head-up tilt test (HUT) have been rarely reported. The purpose of this study was to assess the characteristics of these seizure-like activities and evaluate whether there are differences in the clinical ...

To confirm the usefulness of head-up tilt test (HUT) in neurocardiogenic syncope (NCS) with complicating clinical features, retrospective analysis were done on 12 selected children. The age at onset was 12.7 +/- 1.9 (mean +/- SD) years. Associated clinical features were postoperative congenital heart disease (PO CHD) in 3, coexistent arrhythmia in 8 (persistent ventricular arrhythmia during exe...

the supine position for 10 minutes. The test consisted of 2 Introduction The head-up tilt test (HUTT) is a useful diagnostic tool for evaluating suspected neurocardiogenic syncope. Pharmacologic provocation with isoproterenol, adenosine, or nitroglycerin (NTG) is frequently used to facilitate the induction of syncope during HUTT. Studies have reported the occurrence of ventricular arrhythmias d...

Syncope is defined as a sudden temporary loss of consciousness and postural tone that is associated with spontaneous recovery. Vasovagal or neurocardiogenic syncope is a common and usually benign cause of syncope. The mechanism may be cardioinhibitory, vasodepressor, or both. Diagnosis is usually made by a typical patient history with a definite trigger. Although vasovagal syncope is considered...

BACKGROUND Previous reports that used head-up tilt testing and adenosine administration have suggested that adenosine may be an important endogenous mediator that may trigger a vasovagal response in susceptible patients. However, little is known regarding endogenous adenosine plasma levels (APLs) during vasovagal syncope provoked by tilt testing. The aim of this study was to determine whether A...

tk;1Passive head-up tilt and exercise result in specific changes in the spectral characteristics of heart rate (HR) variability as a result of reduced vagal and enhanced sympathetic outflow. Recently analytic methods based on nonlinear system theory have been developed to characterize the nonlinear features in HR dynamics. This study was designed to assess the changes in the fractal and complex...

PURPOSE The aim of the study was to randomly compare clomipramine, used as a challenge-agent during head-up tilt test, with isoproterenol, used in the conventional test, in patients with vasovagal syndrome. SUBJECTS AND METHODS The serotonergic re-uptake inhibitor clomipramine was infused (5mg in 5min) at the start of head-up tilt test (Clom-HUT) in 126 patients (mean age 41+/-16 years) with ...