The significance of quantitative electrocardiogram analysis in the diagnosis of fulminant myocarditis among Pediatric patients

BACKGROUND: The electrocardiogram (ECG) serves a critical function in the diagnosis of fulminant myocarditis(FM). Nevertheless, the utility of qualitative ECG analysis in diagnosing this condition remains limited. To date, there is a lack of published studies investigating the application of quantitative electrocardiogram analysis for the diagnosis of FM in pediatric populations. METHODS: We conducted a retrospective cohort study in 79 patients with acute myocarditis (AM). Participants were categorized into FM(26 cases) and non-fulminant myocarditis (NFM) groups(53 cases) according to their clinical manifestations. Comprehensive clinical data and results from auxiliary examinations were systematically gathered. Furthermore, a control group comprising eighty healthy children undergoing routine physical examinations during the same period was included. RESULTS: The FM group demonstrated a significantly higher incidence of ECG abnormalities relative to the NFM group, notably limb lead low voltage trend (LVT) and chest lead LVT(all P < 0.05). Repolarization abnormalities were frequently observed in both the FM and NFM groups. Quantitative ECG analysis revealed that, except for leads III, aVL, aVF, and V1, QRS complex voltage were significantly reduced in the FM group compared to both NFM and control groups (all P < 0.01). Multivariate logistic regression identified prolonged QRS duration and diminished average limb lead voltage as independent predictors of FM. CONCLUSION: Pediatric patients with FM present with pronounced and severe ECG abnormalities. In pediatric patients with myocarditis, prolongation of QRS duration (>98 ms) or reduction in average limb lead voltage(<0.82mv) serve as critical electrophysiological markers for the early diagnosis of FM.