Approximately 10-15% of patients with COVID-19 will develop myocarditis as a complication. The myocarditis normally presents approximately 10-days into the infection, and it can be difficult to diagnose myocarditis if that patient is also experiencing Acute Respiratory Distress Syndrome.
The clinical features which might suggest a superadded myocarditis include:
- Dramatic decline in the patient’s overall condition
- Increased need for oxygenation
- ECG changes, including sinus tachycardia, diffuse T wave changes, heart block, prolongation of the QT interval
- Chest x-ray findings of pulmonary oedema, although these are difficult to differentiate from ARDS caused by COVID-19
- Biomarkers including troponin T and BNP are often elevated in myocarditis
- Echocardiography findings of impaired LV function, although this test may not be available due to risk of cross infection
Patients with myocarditis can also present with arrhythmias.