Abstract 14076: Myocardial Tissue Characterization and Strain by Cardiac Magnetic Resonance and Their Relationship in Pediatric Patients With Acute Myocarditis Within 2 Weeks of Presentation

Introduction: Cardiac magnetic resonance (CMR) provides rich data on myocardial function, including indices such as strain, as well as tissue characterization. There is no published data on these values within 2 weeks of the diagnosis of myocarditis. We sought to describe these findings in children with acute myocarditis who underwent CMR early after presentation and determine relationships between these values. Methods: We retrospectively reviewed the clinical and imaging data of patients <21 years clinically diagnosed with acute myocarditis and underwent CMR within 14 days of presentation. Those who suffered cardiac arrest or with autoimmune disease, known cardiomyopathy or congenital heart disease were excluded. Strain was measured using CMR feature tracking. Spearman’s correlation was utilized. Significance was P <0.05. Results: 85 patients underwent CMR at a median of 2 days following presentation (IQR 2 - 4) with median age 16.3 years (IQR 14.3, 17.5). Tissue characteristics, ventricular function and strain are listed in Table 1. 77 studies (90.6%) met Lake Louise criteria for myocarditis and 66 (77.7%) showed late gadolinium enhancement. Global circumferential (GCS) and longitudinal strain correlated with T2 values, biventricular ejection fractions, and peak brain natriuretic peptide (BNP); GCS also correlated with T1 values (Table 1, Figure 1). Conclusions: We present the first data on early strain and tissue characterization for myocarditis. Both global longitudinal and circumferential strain correlated with tissue characteristics and serum measures of acute injury. Strain imaging may be a sensitive marker of myocardial injury in patients with myocarditis.