Sex differences in left-ventricular strain in a murine model of coxsackievirus B3 myocarditis

Myocarditis is typically caused by viral infections, but most cases are thought to be subclinical. Echocardiography is often used for initial assessment of myocarditis patients but is poor at detecting subtle changes in cardiac dysfunction. Cardiac strain, such as global longitudinal strain (GLS) and global circumferential strain (GCS), represents an increasingly used set of measurements which can detect these subtle changes. Using a murine model of coxsackievirus B3 myocarditis, we characterized functional changes in the heart using echocardiography during myocarditis and by sex. We found that 2D GLS, 4D mode, and 4D strains detected a significant reduction in ejection fraction and GLS during myocarditis compared to baseline and in males compared to females. Furthermore, worse GLS correlated to increased levels of CD45⁺, CD11b+, and CD3⁺ immune cells. Our findings closely resemble published reports of GLS in patients with myocarditis indicating the usefulness of this animal model for translational studies of myocarditis.