Cardiac MRI in Children with Multisystem Inflammatory Syndrome Associated with COVID-19

Area of Science:

• Pediatric Cardiology
• Infectious Diseases
• Cardiovascular Imaging

Background:

• Multisystem inflammatory syndrome in children (MIS-C) emerged as a significant concern during the COVID-19 pandemic.
• MIS-C often presents with Kawasaki disease-like features, necessitating investigation into cardiac involvement.
• Understanding the cardiac manifestations of MIS-C is crucial for timely diagnosis and management.

Purpose of the Study:

• To investigate cardiac magnetic resonance imaging (CMR) findings in children and adolescents with MIS-C and COVID-19.
• To characterize the nature of myocardial injury in these patients.
• To differentiate between inflammatory and fibrotic changes in the myocardium.

Main Methods:

• Case series of four pediatric patients admitted to intensive care with MIS-C related to COVID-19.
• Clinical assessment including physical examination, laboratory tests, and serology for SARS-CoV-2.
• Cardiac MRI utilizing T2 short tau inversion-recovery (STIR) sequences and native T1 mapping.

Main Results:

• Acute myocarditis was diagnosed in all patients within one week of symptom onset.
• Cardiac MRI demonstrated diffuse myocardial edema on T2 STIR and native T1 mapping.
• No late gadolinium enhancement was observed, indicating absence of replacement fibrosis or focal necrosis.

Conclusions:

• Cardiac MRI findings in MIS-C associated with COVID-19 suggest acute, reversible myocardial edema.
• The absence of late gadolinium enhancement points towards post-infectious myocarditis rather than direct viral invasion or ischemic injury.
• These findings aid in differentiating MIS-C cardiac involvement from other pediatric cardiomyopathies.