Written by Laura Murphy
This is a review of the emergency diagnosis and management of myocarditis, which is inflammation of the myocardium leading to cardiac dysfunction.
Why does this matter?
Myocarditis is associated with significant morbidity and mortality, but it can be tricky to diagnose if you don’t suspect it. We cover the AHA statement on pediatric myocarditis tomorrow.
What a heartache you turned out to be…
Myocarditis can be infectious, toxic, or autoimmune. Viral causes are most common in Europe and North America, and Chagas disease is more common in South/Central America. Complications include heart failure, dysrhythmias, fulminant myocarditis (prior JF post here), and dilated cardiomyopathy.
Presentation: Many patients have a preceding viral prodrome. The most common signs/symptoms are tachypnea, tachycardia, and chest pain in pediatric patients and dyspnea in adults. Suspect this diagnosis in patients with suspected ACS or heart failure without typical risk factors or in those with recent infection or suspected sepsis who worsen with IV fluids.
Workup: ED workup includes ECG, laboratory tests (elevated ESR, CRP, troponin, BNP), and CXR. Point-of-care ultrasound is most useful to identify cardiac dysfunction in the ED. Cardiac MRI, catherization, and endomyocardial biopsy usually occur after admission.
Management: These patients require admission. 50% of patients will fully recover, 30% will decompensate, and 20% will require transplant. ED treatment focuses on management of acute heart failure. NSAIDs should be avoided, as they may worsen mortality. Specific therapies vary based on etiology; IVIG is controversial, and immunosuppressants and steroids can be used for giant cell or eosinophilic myocarditis. Mechanical circulatory support may be indicated for severe cases and requires transfer to transplant center.
Diagnosis and Management of Myocarditis: An Evidence-Based Review for the Emergency Medicine Clinician. J Emerg Med. 2021 Jun 6:S0736-4679(21)00312-7. doi: 10.1016/j.jemermed.2021.03.029. Epub ahead of print.