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Heart rate variability of children with mitral valve prolapse
1Department of Physiology, Faculty of Medicine, National University of Singapore, Singapore.
Insights
Children with mitral valve prolapse (MVP) exhibit reduced heart rate variability (HRV), indicating autonomic dysfunction. This suggests decreased parasympathetic activity and altered sympathovagal balance in pediatric MVP patients.
Area of Science:
- Pediatric Cardiology
- Autonomic Nervous System Function
- Cardiac Electrophysiology
Background:
- Adults with mitral valve prolapse (MVP) may experience autonomic dysfunction.
- Heart rate variability (HRV) is a key indicator of autonomic regulation.
- Understanding autonomic function in pediatric MVP is crucial for clinical management.
Purpose of the Study:
- To investigate heart rate variability (HRV) in children diagnosed with mitral valve prolapse (MVP).
- To compare HRV parameters between children with MVP and healthy controls.
- To explore potential differences in HRV based on symptoms, age, and sex in pediatric MVP.
Main Methods:
- Sixty-seven children with MVP (ages 6-18) and 37 age-matched controls underwent 24-hour Holter electrocardiogram (ECG) monitoring.
- ECG data were analyzed using time-domain and frequency-domain (spectral analysis) methods.
- Analysis included assessment of various HRV indices, including SDANN, high frequency (HF), and low frequency (LF) components.
Main Results:
- Children with MVP demonstrated significantly lower time-domain HRV indices (except SDANN) compared to controls.
- Reduced spectral power in both high frequency (HF) and low frequency (LF) components was observed in children with MVP.
- The low frequency to high frequency ratio (LF/HF) was significantly elevated in children with MVP, suggesting sympathovagal imbalance.
Conclusions:
- Children with MVP exhibit diminished HRV, indicative of autonomic dysfunction.
- Findings suggest decreased parasympathetic activity and a shift in sympathovagal balance in pediatric MVP.
- Sex differences in HRV were noted, with girls showing lower HRV than boys, potentially influenced by heart rate variations.
Abstract:
Studies have indicated that adult patients with mitral valve prolapse (MVP) may have autonomic dysfunction. The purpose of this study was to evaluate heart rate variability (HRV) in children with MVP. Sixty-seven children with MVP (ages 6 to 18 years; 30 boys and 37 girls) were consecutively studied and subdivided into those with or without symptoms. Thirty-seven normal age-matched children (17 boys and 20 girls) were studied as controls. The patients were further divided into 4 age subgroups. HRV was measured using a 24-hour Holter electrocardiogram (ECG) system (Laser SXP Holter Analysis System, Marquette Electronics, Milwaukee, WI). The ECGs were analyzed in both time domain and frequency domain (spectral analysis). Symptomatic and asymptomatic children with MVP were combined for analysis because they were not significantly different in terms of their HRV. All time-domain indices, with the exception of SDANN (SD of the mean of RR intervals in all 5-minute segments of the 24-hour ECG), were significantly lower in children with MVP than in controls. Children with MVP showed significantly lower spectral power of the high frequency (HF) and low frequency (LF) components when compared with controls. The ratio of LF to HF (LF/HF) was significantly higher in children with MVP. Similar differences were observed in the 4 age subgroups. Sex differences in HRV were observed when girls had lower HRV compared with boys. Lower time-domain and frequency-domain indices of HRV in children with MVP are suggestive of decreased parasympathetic activity and a shift in sympathovagal balance. Various factors including differences in heart rate may contribute to sex differences in HRV.