Myocarditis: Difference between revisions
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==Background== | ==Background== | ||
*Inflammatory | *Inflammatory (dilated) cardiomyopathy caused by necrosis of myocytes | ||
* | *Causes: | ||
*Drugs | **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 | |||
**Drugs | |||
***Doxorubicin | |||
***Cocaine | |||
===Phases=== | ===Phases=== | ||
*Acute | *Acute | ||
*Subacute | **Viral cytotoxicity and focal necrosis | ||
*Chronic | *Subacute | ||
**Host's humoral/immune response leading to further cell injury | |||
*Chronic | |||
**Diffuse myocardial fibrosis and cardiac dysfunction | |||
==Clinical Features== | ==Clinical Features== | ||
Revision as of 01:18, 12 March 2019
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
- Drugs
- Doxorubicin
- Cocaine
- Infectious agents
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/few risk factors for CAD
- Age at onset typically between 20-50 years
- Chest pain
- No sensitive symptom or sign but can have flu like syndrome: fever, fatigue, myalgia, nausea and vomiting; tachycardia (out of proportion to fever), tachypnea, new onset CHF
- In Peds: grunting, retractions, ronchi. Infants may have fulminant syndrome: Fever, cyanosis, respiratory distress, tachycardia, cardiac failure, ventricular dysrhythmias
- May have pericardial friction rub
- 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, Acute MI pattern (Usually >1 vessel distribution)
- TropI: Elevated
- Echo: Decreased LVEF, global hypokinesis, regional wall motion abnormalities
- Contrast MR
- Nuclear Study: Widespread uptake indicating myocyte necrosis
- Viral titers
- Endocardial biopsy: Gold standard
Management
- Acute Phase: Antiviral agents may be effective with replicating virus: Pleconaril/Ribavirin
- Subacute: Studies have not shown efficacy of immunosupressants. Peds: High dose IVIG
- Chronic: Treat CHF symptoms, Ventricular Assist Devices (VAD), cardiac transplant
Disposition
- If CHF: Admit to monitored bed; ICU for hemodynamic instability
- Fulminant myocarditis has best prognosis
- Mortality: 20% 1 yr/ 50% 5 yr
- Children with 70% survival rate at 5 yrs
Complications
- Ventricular dysrhythmias
- LV anneurysm
- CHF