No abstract available.
Syncope, Vasovagal*

No abstract available.
Diagnosis* ; Syncope, Vasovagal*

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*

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

PURPOSE: The purposes of this study were to determine short- and long-term fractal correlation behavior of heart rates during daily activity in patients with neurocardiogenic syncope. METHODS: Twenty five patients with histories of neurocardiogenic syncope episodes were included. Their analogue 24h ambulatory Holter electrocardiograms were analyzed. The tape was digitized and the digitized electrocardiograms were partioned into sections of one hour. Then their RR intervals were measured and 20,000 points of RRI were used. To quantify the fractal correlation behavior, we employed the detrended fluctuation analysis, and short-term(n16, alpha2) fractal scaling exponents were calculated. RESULTS: When compared to control, 24-hour average values of alpha1 and all alpha1 values at quarters of each day were significantly higher in patients with syncope. On the contrary, their 24-hour average value of alpha2 and all alpha2 values at quarters of each day were lower in patients with syncope. However, statistical significances were found in 24-hour average value of alpha2 and in alpha2 value at MN-6AM. CONCLUSION: In the syncope patients with neurocardiogenic syncope, short-term fractal scaling exponents of RR interval was significantly high throughout the day. Therefore, their RR intervals were smoother in the short term scale and had a tendency to continue in the same direction of increase or decrease, which may contribute to persistent decrease in heart rate during a syncopal attack.
Child* ; Electrocardiography ; Fractals* ; Heart Rate* ; Heart* ; Humans ; Syncope ; Syncope, Vasovagal*

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*

PURPOSE: Neurocardiogenic syncope (NCS) is the most frequent cause of fainting during adolescence. Inappropriate cardiovascular autonomic control may be responsible for this clinical event. The head-up tilt test has been considered a diagnostic standard, but it is cumbersome and has a high false-positive rate. We performed a study to evaluate whether P-wave dispersion (PWD) could be a useful electrocardiographic parameter of cardiac autonomic dysfunction in children with NCS. METHODS: Fifty-four patients with NCS (28 boys and 26 girls; mean age, 12.3±1.4 years) and 55 age- and sex-matched healthy controls were enrolled. PWD was obtained as the difference between maximum and minimum durations of the P wave on standard 12-lead electrocardiography in all patients and controls RESULTS: The value of PWD was significantly higher in the syncope group than in the control group (69.7±19.6 msec vs. 45.5±17.1 msec, respectively; P<0.001). The minimum duration of P wave was shorter in the syncope group than in the control group (43.8±16.8 msec vs. 53.5±10.7 msec, respectively; P<0.001). Left atrial volume was not different between the groups on transthoracic echocardiography. CONCLUSION: PWD on echocardiography could be used as a clinical parameter in patients with NCS.
Adolescent* ; Child ; Echocardiography ; Electrocardiography* ; Female ; Humans ; Syncope ; Syncope, Vasovagal*

Neurocardiogenic syncope is a relatively common cause of syncope and is diagnosed by head-up tilt test. A wide variety of medical treatment has been proposed, such as beta-blocker, vasoconstrictor, fludrocortisone, and serotonin re-uptake inhibitors. But there are some cases in which these therapies have failed to prevent syncope. Recent report has shown that tilt training is a very effective therapy for recurrent neurocardiogenic syncope. Thus, to determine whether tilt training could prevent symptoms in the patients with recurrent neurocardiogenic syncope, the following study was taken. Five patients diagnosed with neurocardiogenic syncope by head-up tilt test were included. After hospital admission, they were tilted daily until negative response occurred. Negative response was noted in four patients. But tilt training was stopped in one patient because of no response of tilt training. After hospital discharge, the four patients performed tilt training at home by leaning against wall. They were interviewed on the phone eight to eleven months later. They have not experienced any symptoms during the follow-up period. This is the first domestic report of tilt training in patients with neurocardiogenic syncope.
Fludrocortisone ; Follow-Up Studies ; Humans ; Serotonin ; Syncope ; Syncope, Vasovagal*

Causes of syncope are manifold. Hypersensitive carotid sinus reflex is a cause of syncope and other bradycardia symptoms. Rarely, maxillary neoplasms can cause carotid sinus syncope. The authors identified a case of carotid sinus syncope by maxillary neoplasm accompanied by vasovagal syncope.
Bradycardia ; Carotid Sinus ; Maxillary Neoplasms ; Reflex ; Syncope ; Syncope, Vasovagal

Animals ; Neurotransmitter Agents ; metabolism ; Rabbits ; Syncope, Vasovagal ; metabolism ; physiopathology