Acute Perimyocarditis – an ST-Elevation Myocardial Infarction Mimicker: A Case Report

Patient: Male, 40-year-old Final Diagnosis: Probable acute perimyocarditis Symptoms: Chest pain • shortness of breath • tachycardia Medication: — Clinical Procedure: — Specialty: Cardiology OBJECTIVE: Challenging differential diagnosis BACKGROUND: A normal coronary angiogram in ST-elevation myocardial infarction (STEMI) can be considered a myocardial infarction with non-obstructive coronary arteries (MINOCA) until an alternative diagnosis is obtained. However, the COVID-19 pandemic might delay urgent coronary angiography in a resource-limited setting. Perimyocarditis often causes symptoms, such as chest pain, as well as ST-elevation and high cardiac troponin levels. This STEMI mimicker can also cause cardiogenic shock and death when not treated properly. CASE REPORT: A 40-year-old man reported having acute onset of substernal chest pain, which was suspected to be STEMI. The patient was an active smoker without any risk factors or a history of cardiovascular disease. The examination showed elevated cardiac troponin I, ST-elevation in high lateral leads, and regional wall motion abnormality (RWMA) by echocardiogram. Furthermore, thrombolytic therapy had failed, and rescue percutaneous coronary intervention was not performed due to the catheterization laboratory limitation during the COVID-19 pandemic. Before coronary angiography, the patient was scheduled for 2 consecutive days of COVID-19 polymerase chain reaction (PCR) swabs. On the second day of hospitalization, the patient experienced a cardiogenic shock. The COVID-19 PCR results were negative, while coronary angiography revealed normal coronary arteries. The patient was eventually diagnosed with probable acute perimyocarditis. CONCLUSIONS: Myocarditis is implicated in young patients without typical cardiovascular risk factors or in those with recent infection and cardiovascular symptoms mimicking acute coronary syndrome. It might also be present in situations where ST-elevation distribution on the electrocardiogram is discordant with the RWMA observed on the echocardiogram.