Baseline heart rate variability in children and adolescents with vasovagal syncope.
10.3345/kjp.2014.57.4.193
- Author:
Sun Hee SHIM
1
;
Sun Young PARK
;
Se Na MOON
;
Jin Hee OH
;
Jae Young LEE
;
Hyun Hee KIM
;
Ji Whan HAN
;
Soon Ju LEE
Author Information
1. Department of Pediatrics, The Catholic University of Korea, Bucheon St. Mary's Hospital, Bucheon, Korea.
- Publication Type:Original Article
- Keywords:
Vasovagal syncope;
Heart rate;
Child;
Adolescent
- MeSH:
Adolescent*;
Child*;
Heart Rate*;
Humans;
Syncope;
Syncope, Vasovagal*
- From:Korean Journal of Pediatrics
2014;57(4):193-198
- CountryRepublic of Korea
- Language:English
-
Abstract:
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.
