Introduction to Myocarditis

By: Eric Hua

When my roommate in college went to the doctor for a checkup, he was asked to go back for further examination because his heartbeat was beating too quickly. Soon, he was diagnosed with myocarditis and he was suspended from school for one year. Judging from his outward appearance, it didn’t seem like anything was wrong. When we asked him, other than that his heart rate was faster, he didn’t have any particular discomfort. So what are the dangers of myocarditis, how do you diagnose it, and how do you prevent it?

        Myocarditis manifests in different patients very differently, with this variance depending on the extent and severity of the lesions. Some with myocarditis can be completely asymptomatic. Mild patients can show nonspecific symptoms such as fever, cough, and diarrhea. Severe patients can show severe arrhythmia, heart failure, heart source shock and even death.

The symptoms of myocarditis are the following: 1) acute chest pain; 2) heart failure or symptoms of heart failure that occur within a few days to 3 months; 3) palpitations, arrhythmia, syncope, or sudden cardiac death without obvious causes; 4) unexplained cardiogenic shock.

There are 4 types of auxiliary examinations of myocarditis: 

1) ECG changes like ST-T changes, abnormal Q waves, etc. 

2) Myocardial injury markers like increased troponin I or T 

3) Imaging examination (echocardiography or cardiac magnetic resonance) showing abnormal heart structure and function 

4) Features of cardiac histology confirmed by cardiac magnetic resonance: T2WI showed myocardial edema and (Or) Myocardial delayed enhancement scans show enhanced signals.

Myocarditis can be diagnosed if there are clinical realizations and multiple auxiliary examination abnormalities. If there is no clinical manifestation, but there are two or more auxiliary examination abnormalities, the diagnosis of myocarditis can also be confirmed.

Myocarditis should be treated according to clinical symptoms, but patients with myocarditis should avoid exercising too much to reduce the risk of sudden death.