Focused Cardiac Ultrasound Findings for Acute Myocarditis in a Pediatric Emergency Department: A Case Series

BACKGROUND: Pediatric acute myocarditis is a life-threatening condition with nonspecific symptoms that often lead to diagnostic delays. Focused cardiac ultrasound (FoCUS) is used to assess cardiac function in pediatric emergency care; however, reports on its use for acute myocarditis are limited. This study aimed to describe the characteristics of FoCUS used to aid in the diagnosis of acute myocarditis and to assess the concordance of qualitative left ventricular (LV) function assessments between FoCUS and formal echocardiography. METHODS: A retrospective chart review was conducted at a single tertiary pediatric emergency department (PED) between March 2020 and December 2025. Patients diagnosed with acute myocarditis who underwent FoCUS were included. Patients diagnosed with acute myocarditis before their PED visit or those who did not undergo FoCUS nor echocardiography performed by a pediatric cardiologist were excluded. RESULTS: Eleven patients were included in the study. The median age was 8 years, and 36.4% were male. Chest pain and hypotension were the most common indications for FoCUS. FoCUS was performed by novice users and FoCUS experts in seven and four patients, respectively. Parasternal long-axis, parasternal short-axis, apical four-chamber, subxiphoid four-chamber, and subxiphoid inferior vena cava views were obtained in eight, five, two, six, and five patients, respectively. Nine patients had abnormal LV systolic function. Qualitative FoCUS assessment of LV systolic function was concordant with formal echocardiography in all included cases. CONCLUSION: This study demonstrated that FoCUS can be a useful adjunctive tool for expediting the diagnosis of acute myocarditis in a PED.