Diagnostic markers of acute myocarditis in children

One of the key tasks of modern cardiology is the timely diagnosis of acute myocarditis. Myocardial inflammation can cause serious cardiac disorders and poses a threat to the patient’s life.

The aim of the study was to evaluate the frequency of cardiac arrhythmias, conduction, and structural and functional changes in patients with acute myocarditis hospitalized in the Minsk city children’s infectious diseases hospital in 2015–2025.

Materials and methods. 55 patients were examined. ECG data, Echocardiography data and laboratory markers (troponin I, myoglobin, proBNP) were analyzed.

Results. The viral etiology of the disease was confirmed in 81.8% of cases (Enteroviruses 18.2%, Influenza A 10.9%, SARS-CoV-2 7.3%). Rhythm/conduction disorders were detected in 70.9% of patients and were represented by: sinus arrhythmia in 20% of patients, extrasystoles (30.9%; χ2 = 16.04, p = 0.001; 58.8% were ventricular), AV blockages of the II-III stage (27.8%), blockages of the legs of the bundle of His (23.6%; χ2 = 13.13, p = 0.003). An increase in the BWR and CSR of the left ventricle (27.3% and 38.2% of patients according to the Z-score), a decrease in LV in 30.9% of patients with a Z-score and LV score of less than 28% in 34.5% of cases correlated with the level of proBNP (p = 0.38, p = 0.048) and the clinic of decompensation (tachycardia p = –0.32, p = 0.04).

Conclusion. Acute myocarditis is associated with a high incidence of arrhythmias, which we identified in 70.9% of cases. It was found that prolongation of the QT interval (up to 486 ms in 20%) and Tpe (23.6%) is associated with an increase in proBNP (p = 0.74, p = 0.037 for QT).; p = –0.78, p = 0.022 for Tpe) and CRP (p = 0.45, p = 0.004), T wave inversion (38.2%) and troponin I (20%), indicating myocardial electrical instability as a marker of early left ventricular overload.

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