No abstract available.
Syncope*

No abstract available.
Syncope*

No abstract available.
Syncope, Vasovagal*

No abstract available.
Syncope* ; Urination*

BACKGROUND: Oral beta-blocker is initially used to prevent the symptons in patients with vasovagal syncope or presyncope. But, beta-blocker treatment may actually cause worsening of symptoms in some patients. The purpose of the present study was to evaluate the efficacy of oral beta-blocker in preventing symptoms during repeat head-up tilt test in patients who had a positive response in initial head-up tilt test. METHOD: Patients. Among the 150 patients with unexplained syncope or presyncope who underwent head-up tilt from October 1994 to January 1996, forty-three patients, who were taking beta-blocker and underwent repeat head-up tilted test, were included in this study. Initial head-up tilt test. Each patients was tilted to the 70 degree upright position for 30 minutes. If the test was negative in the baseline tilt, intravenous isoproterenol was started at 1 (micro)g/min and then increased by 1 (micro)g/min every three minutes to al maximum of 5 (micro)g/min while maintaining 70 degree upright position. Repeat head-up tilt test. The test was repeated while each patients was taking atinolol. The repeat test was continued until reaching at the stage where each patient had a positive response in initial test. RESULTS: 1) In initial head-up tilt test, most (91%) of a positive response occured during isoproterenol provocation. 2) In repeat head-up tilt test on atenolol, thirty-four patients(79%) had a negative response. But nine patients(21%) still had a positive response. 3) Nonresponsive group showed younger age and shorter time period to a positive response in initial head-up tilt test than responsive group. CONCLUSION: It may be useful to assess the effectiveness of beta-blocker by repeat head-up tilt before deciding long term treatment, especially younger age group.
Adult* ; Atenolol ; Humans ; Isoproterenol ; Syncope* ; Syncope, Vasovagal*

No abstract available.
Bradycardia ; Infarction ; Syncope

No abstract available.
Diagnosis* ; Syncope, Vasovagal*

No abstract available.
Heart Arrest* ; Syncope*

Endocarditis ; Humans ; Syncope

PURPOSE: This study aimed to evaluate the autonomic imbalance in syncope by comparing the baseline heart rate variability (HRV) between healthy children and those with vasovagal syncope. METHODS: To characterize the autonomic profile in children experiencing vasovagal syncope, we evaluated the HRV of 23 patients aged 7-18 years and 20 healthy children. These children were divided into preadolescent (<12 years) and adolescent groups. The following time-domain indices were calculated: root mean square of the successive differences (RMSSD); standard deviation of all average R-R intervals (SDNN); and frequency domain indices including high frequency (HF), low frequency (LF), normalized high frequency, normalized low frequency, and low frequency to high frequency ratio (LF/HF). RESULTS: HRV values were significantly different between healthy children and those with syncope. Student t test indicated significantly higher SNDD values (60.46 ms vs. 37.42 ms, P=0.003) and RMSSD (57.90 ms vs. 26.92 ms, P=0.000) in the patient group than in the control group. In the patient group, RMSSD (80.41 ms vs. 45.89 ms, P=0.015) and normalized HF (61.18 ms vs. 43.19 ms, P=0.022) were significantly higher in adolescents, whereas normalized LF (38.81 ms vs. 56.76 ms, P=0.022) and LF/HF ratio (0.76 vs. 1.89, P=0.041) were significantly lower in adolescents. In contrast, the control group did not have significant differences in HRV values between adolescents and preadolescents. CONCLUSION: The results of this study indicated that children with syncope had a decreased sympathetic tone and increased vagal tone compared to healthy children. Additionally, more severe autonomic imbalances possibly occur in adolescents than in preadolescents.
Adolescent* ; Child* ; Heart Rate* ; Humans ; Syncope ; Syncope, Vasovagal*