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 can affect the heart's ability to pump normally and can lead to irregular heart rhythms (arrhythmias), heart failure, heart attacks and/or strokes. 

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, and echocardiograms.

The relevant medical specialist is a Cardiologist but this condition can be diagnosed by General Physicians. Hospital assessment and management is recommended for a period of time for most individuals with myocarditis. 

Additional diagnoses covered by these SOPs

• 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

The clinical onset is the earliest time, prior to the confirmation of the disease, that the symptoms and signs consistent with myocarditis have been documented. Individuals with myocarditis may present with chest pain, shortness of breath, rapid or irregular heartbeats, fever, fatigue and/or swelling in the legs, ankles and feet. 

Clinical worsening

Myocarditis management requires treatment of the identified underlying cause and any associated complications. Overall, the natural history of this condition depends on the cause, severity and how early treatment is initiated. Some people can recover with no ongoing effects whilst others can experience damage to the heart muscle, heart failure or other serious complications. As such, if there are concerns about possible clinical worsening, it is recommended that a report be sought from the treating cardiologist to ascertain whether there is a true clinical worsening out of keeping with the natural history of the underlying pathology, and the likely cause of such clinical worsening.