II. Epidemiology
- Ages
- Children: Age <2 years old
- Adolescents: Age 14 to 18 years old
- Adults: Ages 20 to 40 years old
III. Causes
- See Secondary Cardiomyopathy (includes Viral Myocarditis Causes)
IV. Associated Conditions
V. Precautions
- Myocarditis is a clinical diagnosis with no single, definitive noninvasive diagnostic test
- Exercise a high level of suspicion in atypical presentations of common acute cardiopulmonary diseases
VI. Symptoms
- Presentations vary widely
- Most cases are mild and asymptomatic
- However, can be severe and life-threatening (especially in children)
- May be responsible for up to 20% of unexplained cardiac death in young adults
-
Influenza-like illness presentation is common
- Fever (Viral Myocarditis)
- Fatigue
- Myalgias
- Arthralgias
- Malaise
-
Chest symptoms
- Palpitations
- Pleuritic Chest Pain
- Sinus Tachycardia out of proportion to other findings (or other Dysrhythmia)
- Dyspnea on exertion
- Heart Block (Lyme Disease, Sarcoidosis, giant cell Myocarditis)
- Symptoms related to secondary events and decompensation
- Infant and young child presentation
- Poor feeding
- Lethargy
- Respiratory distress (Tachypnea, intercostal retractions, grunting)
- Gastrointestinal Symptoms (Nausea, Vomiting or Abdominal Pain)
VII. Signs
- Pericardial Friction Rub
- Loud S3 Gallop
-
Sinus Tachycardia (or other fast Dysrhythmia)
- Out of proportion to other causes (e.g. beyond what would be expected with fever alone)
- Weak pulses
VIII. Labs
- Complete Blood Count
-
Troponin I increased
- Very high Troponins may be seen in Myocarditis (higher than in Acute Coronary Syndrome)
- Often normal, especially in children
- Brain Natriuretic Peptide (BNP, ntBNP) increased
- Thyroid Stimulating Hormone (TSH)
- Lactic Acid
- Venous Blood Gas (VBG)
- Serum Aspartate Aminotransferase
- Nonspecific increase is also seen with Kawasaki Disease
- Acute phase reactants
- Erythrocyte Sedimentation Rate (ESR) >60 mm/h
- C-Reactive Protein (CRP) increased
IX. Diagnostics: Electrocardiogram
- Sinus Tachycardia
- QRS abnormality (associated with worse prognosis)
- Low-voltage QRS Complexes
- Wide QRS Complex
- Pathologic Q Waves
- Diffuse EKG changes (all leads)
- Saddle-shaped ST Segment Elevation progresses to T Wave Inversion
- EKG normalizes in 2 months
- Conduction abnormalities may occur
- Heart Block including complete Heart Block (Lyme Disease, Sarcoidosis, giant cell Myocarditis)
X. Imaging
-
Chest XRay
- Cardiomegaly in 50% cases
- Pulmonary vascular congestion
- Pleural Effusions
-
Echocardiogram
- Dilated Cardiomyopathy
- Left Ventricular Dilation
- Decreased ejection fraction
-
Cardiac MRI
- Most accurate non-invasive imaging modality to diagnose Myocarditis
- Assess LV Ejection fraction, wall thickness, ventricle size, tissue injury
- Endomyocardial Biopsy Indications
- Fulminant myocardititis
- Acute Dilated Cardiomyopathy with VT or complete Heart Block refractory to standard management
XI. Differential Diagnosis
XII. Management
- Management is typically symptomatic
- Severe, Fulminant Myocarditis requires Critical Care
- Hypotension
- Severe Congestive Heart Failure
- Cardiogenic Shock
- Complete Heart Block
- Specific management may be based on underlying cause
- Disposition is based on severity of clinical presentation
- Initial inpatient management is waranted in severe cases
- Most acute Myocarditis in young children are admitted, often to Intensive Care unit
- Young children may present in severe CHF, and require intensive management
- Endotracheal Intubation
- Inotropic support (Dopamine, Dobutamine, Milrinone)
- Consider Diuretics (Furosemide) if hypertensive and Fluid Overload
- Afterload reduction
- Dysrhythmia management (e.g. Amiodarone, Lidocaine)
- Transfer to pediatric Intensive Care with ECMO capability
- Various agents have been used historically, especially for Viral Myocarditis (e.g. coxsachievirus)
- IV Ig (effective in Kawasaki's Disease, but not in Viral Myocarditis)
- Immunosuppresants (Corticosteroids, Cyclosporine) have not been effective in Viral Myocarditis
XIII. Complications
- Syncope
- Sudden Cardiac Death (Dysrhythmia associated)
- Cardiac Tamponade
XIV. References
- Claudius, Behar, Salway and Kearl in Herbert (2018) EM:Rap 18(5): 1-3
- DeMeester and Weinstock in Swadron (2022) EM:Rap 22(5): 15-7
- Sharrief in Herbert (2012) EM:Rap 12(5): 8
- Klauer (2013) Congestive Heart Failure and Myocarditis, EM Bootcamp, CEME
- Pacheco and Rawani-Patel (2019) Crit Dec Emerg Med 33(5): 3-11
Images: Related links to external sites (from Bing)
Related Studies
| Definition (CHV) | inflammation of the heart muscle |
| Definition (NCI) | Inflammation of the muscle tissue of the heart. |
| Definition (NCI_CTCAE) | A disorder characterized by inflammation of the muscle tissue of the heart. |
| Definition (MSH) | Inflammatory processes of the muscular walls of the heart (MYOCARDIUM) which result in injury to the cardiac muscle cells (MYOCYTES, CARDIAC). Manifestations range from subclinical to sudden death (DEATH, SUDDEN). Myocarditis in association with cardiac dysfunction is classified as inflammatory CARDIOMYOPATHY usually caused by INFECTION, autoimmune diseases, or responses to toxic substances. Myocarditis is also a common cause of DILATED CARDIOMYOPATHY and other cardiomyopathies. |
| Definition (CSP) | inflammation of the muscular walls of the heart. |
| Concepts | Disease or Syndrome (T047) |
| MSH | D009205 |
| ICD9 | 429.0 |
| ICD10 | I51.4 |
| SnomedCT | 155380004, 251060004, 195119007, 50920009 |
| English | Myocarditides, Myocarditis NOS, Myocarditis, unspecified, Myocarditis, myocarditis (diagnosis), myocarditis, Myocarditis [Disease/Finding], Myocarditis NOS (disorder), Myocardial inflammation (finding), MYOCARDITIS, Myocarditis (disorder), inflammation; myocardium, myocardium; inflammation, Myocarditis, NOS, Myocardial inflammation |
| French | MYOCARDITE, Myocardite, non précisée, Myocardite SAI, Myocardite |
| Portuguese | MIOCARDITE, Miocardite NE, Miocardite |
| Spanish | MIOCARDITIS, Miocarditis NEOM, Miocarditis no especificada, miocarditis, SAI, inflamación miocárdica (hallazgo), miocarditis, SAI (trastorno), Myocarditis NOS, inflamación miocárdica, miocarditis (trastorno), miocarditis, Miocarditis |
| Dutch | myocarditis, niet-gespecificeerd, myocarditis NAO, myocard; ontsteking, ontsteking; myocard, Myocarditis, niet gespecificeerd, myocarditis, Myocarditis |
| German | Myokarditis NNB, Myokarditis, unspezifisch, MYOCARDITIS, Myokarditis, nicht naeher bezeichnet, Myokarditis |
| Italian | Miocardite NAS, Miocardite non specificata, Miocardite |
| Japanese | 心筋炎ＮＯＳ, 心筋炎、詳細不明, 心筋炎, ｼﾝｷﾝｴﾝｼｮｳｻｲﾌﾒｲ, ｼﾝｷﾝｴﾝ, ｼﾝｷﾝｴﾝNOS |
| Swedish | Hjärtmuskelinflammation |
| Czech | myokard - zánět, zánět srdečního svalu, myokarditida, Myokarditida, Myokarditida NOS, Myokarditida, blíže neurčená |
| Finnish | Sydänlihastulehdus |
| Russian | MIOKARDIT, МИОКАРДИТ |
| Korean | 상세불명의 심근염 |
| Polish | Zapalenie mięśnia sercowego |
| Hungarian | Myocarditis, Myocarditis, nem meghatározott, Myocarditis k.m.n. |
| Norwegian | Hjertemuskelbetennelse, Myokarditt |
Ontology: Viral carditis (C0151328)
| Concepts | Disease or Syndrome (T047) |
| ICD10 | B33.2 , B33.20 |
| SnomedCT | 186755002 |
| German | Karditis durch Viren |
| Korean | 바이러스 심장염 |
| English | Viral carditis, unspecified, Viral carditis, Viral carditis (disorder), carditis; viral (manifestation), virus; carditis (manifestation) |
| Spanish | carditis vírica, carditis viral (trastorno), carditis viral |
| Dutch | carditis; virus, virus; carditis, Virale carditis |
Ontology: Dilated cardiomyopathy secondary to viral myocarditis (C0264797)
| Concepts | Disease or Syndrome (T047) |
| ICD10 | B33.24 |
| SnomedCT | 30496006 |
| English | Viral cardiomyopathy, viral cardiomyopathy, Dilated cardiomyopathy secondary to viral myocarditis, Dilated cardiomyopathy secondary to viral myocarditis (disorder) |
| Spanish | Cardiomiopatía vírica, miocardiopatía dilatada secundaria a miocarditis virósica, miocardiopatía dilatada secundaria a miocarditis viral (trastorno), miocardiopatía dilatada secundaria a miocarditis viral, miocardiopatía dilatada secundaria a miocarditis vírica |
| Portuguese | Cardiomiopatia viral |
| Dutch | virale cardiomyopathie |
| Italian | Cardiomiopatia virale |
| French | Cardiomyopathie virale |
| German | Virus-induzierte Kardiomyopathie |
| Czech | Virová kardiomyopatie |
| Japanese | ｳｲﾙｽｾｲｼﾝｷﾝｼｮｳ, ウイルス性心筋症 |
| Hungarian | Vírusos cardiomyopathia |
Ontology: Viral myocarditis (C0276138)
| Concepts | Disease or Syndrome (T047) |
| ICD10 | B33.22 |
| SnomedCT | 89141000 |
| Italian | Miocardite virale, Miocardite virale NAS |
| Dutch | myocarditis viraal NAO, myocarditis; viraal, viraal; myocarditis, virale myocarditis |
| French | Myocardite virale SAI, Myocardite virale |
| German | Myokarditis viral NNB, virale Myokarditis |
| Portuguese | Miocardite viral NE, Miocardite viral |
| Spanish | Miocarditis vírica NEOM, miocarditis virósica, miocarditis vírica, miocarditis viral (trastorno), miocarditis viral, Miocarditis vírica |
| Japanese | ウイルス性心筋炎, ウイルス性心筋炎ＮＯＳ, ｳｲﾙｽｾｲｼﾝｷﾝｴﾝNOS, ｳｲﾙｽｾｲｼﾝｷﾝｴﾝ |
| Czech | Virová myokarditida, Virová myokarditida NOS |
| English | Myocarditis viral NOS, viral myocarditis, myocarditis viral, Viral myocarditis, Viral myocarditis (disorder), myocarditis; viral, viral; myocarditis, Viral myocarditis, NOS |
| Hungarian | vírusos myocarditis, Viralis myocarditis k.m.n. |
