Fig. 1: Histology of the three pathologically defined patient groups.

Depicted are histologic images of slides stained with H&E (A–C), immunohistochemistry for the macrophages marker CD68 (D–F), immunohistochemistry for the T-lymphocyte marker CD3 (G–I), and in situ hybridization for SARS-CoV-2 (J–L) for cases with myocarditis along with SARS-CoV-2⁺ cells in the myocardium (V⁺M⁺, A, D, G, J), negative for myocarditis but with SARS-CoV-2⁺ cells in the myocardium (V⁺M^–, B, E, H, K), and negative for both myocarditis and myocardial SARS-CoV-2⁺ cells (V^–M^–, C, F, I, L). There is inflammation with myocardial injury (arrow) in the V⁺M⁺ case (A) compared with inflammation (arrow) without injury in the V⁺M^– case (B). Arrows indicate CD68⁺ macrophages (D–F), CD3⁺ lymphocytes (G–I), and SARS-CoV-2⁺ cells (J, K). Scale bars represent 40 μm (A–I) and 80 μm (J–L).