Myocarditis G048

Changes from Previous Instruments:

ICD Coding

• ICD-10-AM Codes: I40; I41, I01.2; I09.0; I51.4

Brief description:

Myocarditis involves inflammation of the heart muscle (myocardium). This condition may impair cardiac function and may result in arrhythmias, heart failure, cardiogenic shock or sudden cardiac death.

Myocarditis may occur as an acute, chronic, infectious, autoimmune, toxic or fulminant condition.

Confirming the diagnosis:

Diagnosis of myocarditis is based on a combination of clinical findings and exclusion of other causes of cardiac dysfunction. Investigations may include electrocardiograms (ECGs), serum biomarkers via blood tests, echocardiograms, and cardiac MRIs. Symptoms and signs may include chest pain, dyspnoea, palpitations, arrhythmias, fatigue or manifestations of heart failure.

Management and confirmation are usually undertaken by a cardiologist. Hospital assessment and monitoring are commonly required, particularly in acute or severe presentations.

Additional diagnoses covered by SOP

• Acute myocarditis
• Chronic myocarditis
• Viral myocarditis
• Bacterial myocarditis
• Autoimmune myocarditis
• Giant cell myocarditis
• Fulminant myocarditi
• Toxic myocarditis 

Conditions not covered by these SOPs 

• Cardiomyopathy *
• Acute coronary syndrome * Ischaemic Heart Disease SoP
• Ischaemic heart disease *
• Pericarditis *                         

* another SOP applies  - the SOP has the same name unless otherwise specified

# non-SOP condition

Clinical onset

Clinical onset generally corresponds to the earliest time at which symptoms and signs attributable to myocarditis first become clinically evident. Symptoms may include chest pain, shortness of breath, palpitations, arrhythmias, fatigue or manifestations of heart failure.

Clinical worsening

Myocarditis management requires treatment of the identified underlying cause and any associated complications. Clinical worsening may be indicated by worsening cardiac dysfunction, arrhythmias, heart failure, cardiogenic shock or progression of myocardial injury. Severity and prognosis depend on the underlying cause, extent of myocardial inflammation and timeliness of treatment. Specialist advice should be sought when assessing for possible clinical worsening and progression beyond the normal clinical course.