Heart rate variability in children and adolescents with incidentally found early repolarization pattern

Author(s): Ahmet Fatih Arinc, Sule Arici, Figen Akalin

Aim: Early Repolarization (ER) on Electrocardiogram (ECG) was considered as a benign finding until the emergence of patients with fatal arrhythmia and sudden death. Its importance in childhood is unknown. We investigated the risk of premature death and arrhythmia in children with incidentally found early repolarization using ECG and heart rate variability parameters. Method: The study group consisted of healthy children between 6-18 years of age with early repolarization and the control group without early repolarization. All the children were evaluated by medical history, physical examination, echocardiography, 12-lead ECG, and 24-hour Holter. ECG parameters; P wave, QTc, JT, Tp-e dispersion; “Time-domain” parameters, SDANN, SDNN-i, r-MSSD, pNN50 and “Frequencydomain” parameters HF, LF, LF/HF were obtained. Results: Heart rate was lower in the study group (p=0.020). There was no difference between the groups regarding P, QTc, and Tp-e dispersion. JT dispersion was high in the study group (p=0.025). The interventricular septum was thicker in the study group (p=0.030). LF/HF (p=0.045), awake HF, and LF/HF (p=0.046, p=0.036) were higher in the study group. Heart rate variability has increased in favor of parasympathetic activity in males. Those with J waves in the inferolateral leads had higher heart rates and lower SDNN and VLF during sleep than those with only in the inferior lead (p=0.049, p=0.040, and p=0.040). Conclusion: Incidental early repolarization in children did not indicate increased risk for cardiac events. It was related to parasympathetic activity, inferolateral early repolarization may be relatively riskier.