Myocarditis, Noninfectious

Key Features

• Causes include

  • Autoimmune diseases

    • Dermatomyositis

    • Inflammatory bowel disease

    • Rheumatoid arthritis

    • Sjögren syndrome

    • Systemic lupus erythematosus

    • Granulomatosis with polyangiitis

    • Giant cell myocarditis

  • Drugs

    • Aminophylline

    • Amphetamine

    • Anthracycline

    • Catecholamines

    • Chloramphenicol

    • Cocaine

    • Cyclophosphamide

    • Doxorubicin

    • 5-Fluorouracil

    • Methysergide

    • Phenytoin

    • Trastuzumab

    • Zidovudine

  • Hypersensitivity reactions due to drugs

    • Azithromycin

    • Benzodiazepines

    • Clozapine

    • Cephalosporins

    • Dapsone

    • Dobutamine

    • Lithium

    • Diuretics

    • Thiazide

    • Methyldopa

    • Mexiletine

    • Streptomycin

    • Sulfonamides

    • Nonsteroidal anti-inflammatory drugs

    • Tetanus toxoid

    • Tetracycline

    • Tricyclic antidepressants

  • Hypersensitivity reactions due to venoms

    • Bee, wasp

    • Black widow spider

    • Scorpion

    • Snake

  • Systemic diseases

    • Eosinophilic granulomatosis with polyangiitis

    • Collagen diseases

    • Sarcoidosis

    • Kawasaki disease

    • Scleroderma

  • Other

    • Heat stroke

    • Hypothermia

    • Transplant rejection

    • Radiation injury

Clinical Findings

• Clinical presentation varies widely

Diagnosis

• In patients receiving chemotherapy, it is important to look for subtle signs of cardiovascular compromise

• Serial echocardiography or cardiac MRI or both can provide concrete data regarding LV function

• Echocardiography/Doppler myocardial strain patterns may be the first abnormality observed and assessment of the T2 signal from cardiac MRI may provide early detection of cardiotoxicity

• Biomarkers such as B-type natriuretic peptide (BNP or NT-prBNP) may be valuable when serial measures are obtained

• Other biomarkers may appear early in the course of myocardial injury (especially troponin and myeloperoxidase) and may allow for early detection of cardiotoxicity before other signs become evident

Treatment

• High-dose corticosteroids and removal of the offending medication or underlying trigger is used to treat eosinophilic myocarditis

• Calcium channel blockers and nitrates may be effective in documented coronary spasm

• Usual therapy for heart failure or conduction system disease is warranted when symptoms occur