Pneumococcal Myocarditis in an Immunocompetent Young Adult: A Case Report and Literature Review.

Pneumococcal myocarditis is an uncommon complication of invasive pneumococcal disease, although experimental data suggest that cardiac involvement may be more frequent than clinically recognized. We describe the case of an 18-year-old immunocompetent male who developed community-acquired pneumonia complicated by myopericarditis. Streptococcus pneumoniae was isolated from blood cultures. Transthoracic echocardiography revealed a reduced left ventricular ejection fraction (40-45%) with pericardial effusion, and cardiac MRI confirmed functional impairment without evidence of necrosis or inflammation. The patient was treated with a 14-day course of intravenous antibiotics alongside supportive care, resulting in full clinical and cardiac recovery. This case emphasizes the under-recognized risk of myocarditis in the context of pneumococcal pneumonia, underscores the importance of routine cardiac evaluation, and highlights the need for heightened clinical awareness to ensure timely diagnosis and management.