[II-JCKAP2-4] Prognosis and Characteristics of Initial Electrocardiographic Findings in Pediatric Acute Myocarditis
Keywords:acute myocarditis, electrocardiogram, amplitude
Objective: Some pediatric patients with acute myocarditis do not present significant abnormalities on their initial electrocardiogram (ECG). The present study aimed to investigate the prognosis and ECG characteristics of a series of such patients.
Methods: Pediatric patients with acute myocarditis at the study center between March 2010 and December 2023 were identified and classified into two groups: Group A, comprising patients with significant ST elevation or rhythm abnormalities at the initial diagnosis; and Group B, comprising those without either. The prognosis of the groups was compared. Later, the ECG findings of Group B were compared with those of age- and sex-matched, healthy controls.
Results: No significant difference was found between Group A (n=16) and Group B (n=9) in terms of mortality, need for extracorporeal membrane oxygenation (ECMO), temporary pacing system or maximum serum troponin T. In Group B, the QRS amplitude on all the leads except V5 was significantly lower than in the control group (0.90 mV vs. 1.68 mV on lead II; p<0.001) while heart rate, QRS duration, and corrected QT interval did not differ significantly.
Conclusions: Although the initial ECG showed neither ST elevation nor any rhythm disturbance in the pediatric patients with acute myocarditis in the present study, cardiopulmonary circulation has the potential to deteriorate rapidly to the point of requiring mechanical circulatory support. A low QRS amplitude may be a key to identifying severely ill patients with acute myocarditis for referral to an appropriate treatment center.
Methods: Pediatric patients with acute myocarditis at the study center between March 2010 and December 2023 were identified and classified into two groups: Group A, comprising patients with significant ST elevation or rhythm abnormalities at the initial diagnosis; and Group B, comprising those without either. The prognosis of the groups was compared. Later, the ECG findings of Group B were compared with those of age- and sex-matched, healthy controls.
Results: No significant difference was found between Group A (n=16) and Group B (n=9) in terms of mortality, need for extracorporeal membrane oxygenation (ECMO), temporary pacing system or maximum serum troponin T. In Group B, the QRS amplitude on all the leads except V5 was significantly lower than in the control group (0.90 mV vs. 1.68 mV on lead II; p<0.001) while heart rate, QRS duration, and corrected QT interval did not differ significantly.
Conclusions: Although the initial ECG showed neither ST elevation nor any rhythm disturbance in the pediatric patients with acute myocarditis in the present study, cardiopulmonary circulation has the potential to deteriorate rapidly to the point of requiring mechanical circulatory support. A low QRS amplitude may be a key to identifying severely ill patients with acute myocarditis for referral to an appropriate treatment center.