PURPOSE: Initial orthostatic hypotension is typically associated with active standing and normal autonomic function. Some adolescents in the present study displayed initial orthostatic hypotension during passive tilting, and we hypothesized that this condition was due to abnormal autonomic function. METHODS: The present study compared autonomic functioning in two groups of adolescents: patients with a diagnosis of initial orthostatic hypotension according to the tilt table test and patients with typical symptoms of initial orthostatic hypotension but normal tilt table test results. RESULTS: Significantly higher total composite autonomic severity scores and considerably higher adrenergic index were noted in the tilt table tested group. CONCLUSION: Initial orthostatic hypotension is possibly associated with autonomic dysfunction, especially abnormal vasoconstrictive ability, in individuals diagnosed with a tilt table test. Clinicians should take note of autonomic function when performing diagnoses of initial orthostatic hypotension using the tilt table test.
Adolescent ; Humans ; Hypotension, Orthostatic ; Tilt-Table Test

Aged ; Humans ; Syncope, Vasovagal ; Tilt-Table Test

The causes of a transient loss of consciousness (TLOC) are divided into syncope, epileptic seizures, cerebrovascular diseases and functional disorders such as hyperventilation (HV) syndrome, psychogenic pseudosyncope. The differential diagnosis of TLOC is may be difficult due to lack of history, misleading features, or confusion over the definition of syncope. We have experienced a rare case of HV syncope that TLOC developed after HV from mental stress, and differentiated by head-up tilt table test with transcranial doppler.
Diagnosis, Differential ; Epilepsy ; Humans ; Hyperventilation* ; Syncope* ; Tilt-Table Test* ; Unconsciousness

Child ; Humans ; Syncope, Vasovagal/therapy* ; Tilt-Table Test

Child ; Humans ; Postural Orthostatic Tachycardia Syndrome ; diagnosis ; Tilt-Table Test

BACKGROUND AND OBJECTIVES: The head-up tilt test (HUT) is widely used for the diagnosis of vasovagal syncope. To improve the sensitivity of the test, provocation with isoproterenol is frequently used. The aim of this study was to evaluate the values of isosorbide dinitrate spray as a provocation drug in the HUT. SUBJECTS AND METHODS: Two hundred patients, undergoing baseline HUT (60 degrees for 20 minutes) for suspected vasovagal syncope or presyncope and unexplained dizziness, were enrolled. If the baseline HUT was negative, isosorbide dinitrate (2.5 mg) spray was applied sublingually (group I, n=93), or isoproterenol (3 microgram/min) infused (group II, n=93), in a randomized fashion. The values of isosorbide dinitrate and isoproterenol were compared in those patients that developed a positive vasovagal response or who completed the drug-provocative HUT. RESULTS: Syncope was similarly reproduced in both groups (47.7 vs. 41.9%, p>0.05). Type I responses were most common in both groups, and types I and II responses were more common in group I than group II (78.0 vs. 55.6% and 12.2 vs. 5.6%, p<0.05, respectively). The average time to a positive response was longer in group I than group II (8.5+/-3.4 vs. 6.1+/-3.6 minutes, p<0.01). The sensitivity and specificity of the drug-provocative HUT were significantly higher in group I than group II (73.5 and 87.5% vs. 58.5 and 71.1%; respectively, p<0.01). The incidence of minor adverse effects were similar in both groups, but serious cardiac side effects were significantly more common in group II than group I (4.3 vs. 0%, p<0.05). CONCLUSION: Sublingual isosorbide dinitrate spray may be used as a simple, effective and well tolerated provocative drug during HUT.
Diagnosis ; Dizziness ; Humans ; Incidence ; Isoproterenol* ; Isosorbide Dinitrate ; Sensitivity and Specificity ; Syncope ; Syncope, Vasovagal ; Tilt-Table Test

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.
Blood Pressure* ; Humans ; Hypotension, Orthostatic* ; Orthostatic Intolerance ; Respiration ; Sweat ; Tilt-Table Test

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 (P<0.05). The coincidence rate of HR or HRD for the diagnosis of POTS in males was higher than that in females at 5 minutes of HUTT (P<0.05), while the coincidence rate of HR or HRD for the diagnosis of POTS in males was lower than that in females at 10 minutes of HUTT (P<0.05). The coincidence rate of HR for the diagnosis of POTS was higher in the >12 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.
Adolescent ; Blood Pressure ; Child ; Female ; Heart Rate ; Humans ; Male ; Postural Orthostatic Tachycardia Syndrome ; Tilt-Table Test

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.
Diagnosis ; Dizziness ; Humans ; Hypotension, Orthostatic ; Postural Orthostatic Tachycardia Syndrome ; Supine Position ; Tilt-Table Test ; Valsalva Maneuver

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.
Blood Pressure ; Heart Rate ; Humans ; Nonlinear Dynamics ; Syncope ; Syncope, Vasovagal ; Tilt-Table Test