Myocarditis in Adult-Onset Still's Disease: Case-Based Review.

Cardiac involvement in adult-onset Still's disease (AOSD) usually manifests as a pericardial disease. Myocarditis is uncommon (prevalence of 7%). However, the cardiocirculatory failure is the second cause of life-threatening AOSD. Herein, we report the case of a 38-year-old man who was diagnosed with myocarditis caused by AOSD. He was treated medically with steroids and methotrexate, and his course was favorable. A literature search in PubMed/MEDLINE and Scopus databases from 1971 to 2019 identified 47 additional cases of myocarditis and AOSD. The main features found in these reports were reviewed and are the following: (i) myocarditis is a rare complication of AOSD manifested by fever, chest pain, dyspnea, and tachycardia; (ii) cardiac biomarkers, electrocardiogram (ECG), transthroracic echocardiography (ECHO), and cardiac magnetic resonance imaging (MRI) are useful noninvasive diagnostic tools; and (iii) myocarditis is a potentially life-threatening complication of AOSD but responds positively to steroids and other immunomodulatory drugs. This review suggests that this entity should be suspected in cases of acute febrile myocarditis after ruling out other causes since a prompt treatment results in a good prognosis.