Myocarditis
This page is for adult patients. For pediatric patients, see: myocarditis (peds)
Background
- Inflammatory (dilated) cardiomyopathy caused by necrosis of myocytes
Causes
- Infectious agents
- Enterovirus (Coxsackie B) and adenovirus most common
- Influenza A and B
- Hepatitis B
- Beta-hemolytic streptococcus
- Mycoplasma
- Mumps
- CMV
- Toxoplasma
- Chagas (most common cause worldwide)
- Trichinosis
- Diphtheria
- Lyme disease
- COVID-19[1]
- Drugs
Phases
- Acute
- Viral cytotoxicity and focal necrosis
- Subacute
- Host's humoral/immune response leading to further cell injury
- Chronic
- Diffuse myocardial fibrosis and cardiac dysfunction
Clinical Features
- Typically young patients (20 - 50 years) with few risk factors for CAD
- Chest pain
- Pericardial friction rub
- Flu-like symptoms
- Fever, fatigue, myalgia, nausea and vomiting
- Tachycardia (out of proportion to fever)
- Tachypnea
- New onset congestive heart failure
- Pediatric patients:
- Grunting
- Retractions
- Rhonchi
- Infants may have fulminant syndrome
- Consider this diagnosis in the septic-appearing patient who gets WORSE after receiving IV fluids
Differential Diagnosis
Consider other causes of CHF
Chest pain
Critical
- Acute coronary syndromes (ACS)
- Aortic dissection
- Cardiac tamponade
- Coronary artery dissection
- Esophageal perforation (Boerhhaave's syndrome)
- Pulmonary embolism
- Tension pneumothorax
Emergent
- Cholecystitis
- Cocaine-associated chest pain
- Mediastinitis
- Myocardial rupture
- Myocarditis
- Pancreatitis
- Pericarditis
- Pneumothorax
Nonemergent
- Aortic stenosis
- Arthritis
- Asthma exacerbation
- Biliary colic
- Costochondritis
- Esophageal spasm
- Gastroesophageal reflux disease
- Herpes zoster / Postherpetic Neuralgia
- Hypertrophic cardiomyopathy
- Hyperventilation
- Mitral valve prolapse
- Panic attack
- Peptic ulcer disease
- Pleuritis
- Pneumomediastinum
- Pneumonia
- Rib fracture
- Stable angina
- Thoracic outlet syndrome
- Valvular heart disease
- Muscle sprain
- Psychologic / Somatic Chest Pain
- Spinal Root Compression
- Tumor
Evaluation
- ECG
- Sinus tachycardia
- Low voltages
- Prolonged QTc
- AV block
- ST elevations (Usually >1 vessel distribution)
- Elevated troponin
- Echocardiography
- Decreased LVEF
- Global hypokinesis
- Regional wall motion abnormalities
- Contrast MR
- Nuclear Study
- Widespread uptake indicating myocyte necrosis
- Viral titres
- Endocardial biopsy: Gold standard, but rarely used
Management
- Acute phase
- Subacute phase
- Studies have not shown efficacy of immunosupressants
- Pediatric patients may receive high-dose IVIG
- Chronic phase
- Treatment for CHF symptoms
- Ventricular Assist Devices (VAD)
- Cardiac transplant
Disposition
- If CHF is present, admit to monitored bed
- If hemodynamically unstable, admit to ICU
Prognosis
- Fulminant myocarditis has best prognosis
- Mortality: 20% 1 yr/ 50% 5 yr
- Children with 70% survival rate at 5 yrs
Complications
See Also
External Links
References
- ↑ Mele D, Flamigni F, Rapezzi C, Ferrari R. Myocarditis in COVID-19 patients: current problems. Internal and Emergency Medicine. 2021. doi:10.1007/s11739-021-02635-w
- ↑ Mele D, Flamigni F, Rapezzi C, Ferrari R. Myocarditis in COVID-19 patients: current problems. Internal and Emergency Medicine. 2021. doi:10.1007/s11739-021-02635-w