Altered heart rate variability and ventricular repolarization in children with mitral valve prolapse

Abstract

Objective: The aim of this study was to evaluate heart rate variability (HRV) parameters and ventricular repolarization abnormalities in children with mitral valve prolapse (MVP) compared with healthy controls. Materials and Methods: This retrospective single-center study included 78 children with MVP and 92 healthy controls with similar age and gender distributions. Demographic characteristics, 24-hour Holter-derived HRV parameters, and electrocardiographic measurements were analyzed. HRV indices included SDNN, SDANN, SDANNi, rMSSD, pNN50, total power, VLF, LF, HF, LF/HF ratio, and triangular index. Multiple comparisons were adjusted using the Benjamini–Hochberg false discovery rate (FDR) method. Multivariable linear regression analyses adjusted for age and sex were performed for selected representative variables. Results: Children with MVP demonstrated significantly lower SDANNi, rMSSD, total power, LF, HF, and triangular index values compared with controls after FDR correction. Maximum QTc values were significantly higher in the MVP group. In multivariable regression analysis, MVP remained independently associated with lower HF and rMSSD values and higher maximum QTc values after adjustment for age and gender. No significant differences were observed for LF/HF ratio, SDNN, SDANN, or pNN50 after FDR correction. Conclusion: Children with MVP exhibit reduced parasympathetic modulation together with prolonged ventricular repolarization independently of age and gender. These findings suggest that pediatric MVP may be associated with autonomic and electrophysiological alterations.