Heart rate variability in children with myocarditis presenting with ventricular arrhythmias

Area of Science:

• Pediatric Cardiology
• Electrophysiology
• Autonomic Nervous System Function

Background:

• Myocarditis is inflammation of the heart muscle, often viral in origin, and can lead to serious complications in children.
• Ventricular arrhythmias are a significant concern in pediatric myocarditis, increasing morbidity and mortality.
• Heart rate variability (HRV) reflects autonomic nervous system balance and has been explored as a marker for cardiac conditions.

Purpose of the Study:

• To investigate heart rate variability (HRV) patterns in children diagnosed with viral myocarditis (VMC).
• To compare HRV characteristics between VMC patients with and without ventricular arrhythmias (VAs).
• To assess the potential of HRV as a predictive indicator for VAs in pediatric VMC.

Main Methods:

• A comparative study involving 67 children with VMC (35 with VAs, 32 without VAs) and 30 healthy controls.
• Analysis of time-domain indicators of heart rate variability (HRV) during both lucid and sleep periods.
• Statistical comparison of HRV parameters across the VMC groups and the control group.

Main Results:

• Children with VMC exhibited significantly lower HRV time-domain indicators compared to healthy controls (p<0.05).
• VMC patients with ventricular arrhythmias showed significantly lower HRV than those without VAs (p<0.05).
• Significantly reduced HRV was observed in VMC patients with arrhythmias compared to both controls and VMC patients without arrhythmias during all periods (p<0.05).

Conclusions:

• Reduced HRV in pediatric VMC is likely due to impaired vagal nerve function.
• Ventricular arrhythmias in VMC may develop when HRV reduction is most severe.
• HRV serves as a valuable predictive indicator for the development of ventricular arrhythmias in children with VMC.