Fulminant Myocarditis – Recognition and Management from the AHA

February 12, 2020

Written by Clay Smith

Spoon Feed
This is what you need to know to recognize and manage fulminant myocarditis (FM) in the ED.

Why does this matter?
FM is: “a sudden and severe inflammation of the myocardium resulting in myocyte necrosis, edema, and cardiogenic shock.” It is a masquerader. Here are the pearls and pitfalls to spot it and treat it.

My achy breaky heart
This is an AHA Scientific Statement on FM. Our focus is on ED management.

• Presentation – Dyspnea, chest pain, and arrhythmia, such as atrial or ventricular fibrillation are common presentations. Patients may present in shock and may have acute infectious symptoms; shock may appear septic but is likely cardiogenic. Consider FM in young patients with ACS-like or acute CHF presentation, especially when lacking typical risk factors. Ask about preceding illness. Right heart failure may cause hepatic congestion masquerading as a “liver disease” picture. Consider hypersensitivity FM from drugs like beta-lactams or carbamazepine.

• ECG – It may show low voltage, ST-elevation mimicking acute injury, pericarditis-like changes with diffuse ST-elevation +/- PR depression. Ectopy, ventricular arrhythmias, and conduction blocks (long PR, Mobitz type II) are also common. Look for early changes of widened QRS or PR prolongation.

• Labs – Troponin is usually markedly elevated as is BNP. If eosinophilia, ask about new medications and consider necrotizing eosinophilic myocarditis.

• Imaging – Echocardiogram is the imaging study of choice. MRI or nuclear studies may be done later.

• Treatment – If FM is suspected, don’t give too much fluid. Use norepinephrine as the vasopressor of choice; avoid dopamine. Avoid rate controllers with negative inotropy – they need tachycardia to maintain cardiac output. Avoid NSAIDs – they make sodium retention worse. Involve cardiology early to rule out coronary artery disease and to deploy invasive hemodynamic support if needed.

• Disposition – If transferring with heart failure symptoms, it should be to a transplant center that can also do ECMO.

• Prognosis – Ironically, those with the worst initial hemodynamic collapse often have the best chance of full recovery – if they survive the initial insult.

Source
Recognition and Initial Management of Fulminant Myocarditis: A Scientific Statement From the American Heart Association. Circulation. 2020 Jan 6:CIR0000000000000745. doi: 10.1161/CIR.0000000000000745. [Epub ahead of print]

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