Case Presentation: A 68-year-old male with COPD and prior lung cancer treated with chemotherapy and radiation presented with three days of progressive dyspnea, malaise, and altered mental status. On admission, he was in acute hypoxemic respiratory failure requiring BiPAP. The patient was unvaccinated against SARS-COV-2 and tested positive for the virus. He received dexamethasone and remdesivir. He also received antibiotics for superimposed aspiration pneumonia. On hospital day two, he had nausea and vomiting. Electrocardiogram (ECG) was obtained for QTc evaluation but found PR interval depression and ST segment elevation in leads II, III, and aVF. High-sensitivity troponin was 26,678, eliciting concern for an inferior myocardial infarction. Left heart catheterization demonstrated normal coronary arteries. Echocardiography found an ejection fraction of 60% and no regional wall motion abnormalities. The study quality was limited and could not evaluate the pericardium. The patient had no chest pain during this time. Serial ECG’s throughout the hospitalization found spread of the ST elevations into the anterolateral leads, followed by flattening of the T waves and eventual T wave inversion. Overall, his ECG changes and troponin elevations were attributed to myo-pericarditis secondary to Covid-19. His hypoxemic respiratory failure resolved and he was discharged home.
Discussion: Pericarditis is a non-ischemic inflammatory disease of the pericardium (2). Myopericarditis refers to concomitant myocardial involvement (1,3). Underlying etiologies of pericarditis include infectious and non-infectious categories. Infectious causes include viral, bacterial, fungal, and parasitic. Viral etiologies are the most in the United States. Non-infectious causes include autoimmune, neoplastic, metabolic, traumatic, and drug related (2,4,7). COVID-19-related pericarditis is rare, with an estimated incidence of 1.5%. It is associated with increased all-cause mortality and risk of myocardial infarction (2). The diagnosis of pericarditis is made when there are at least two of the following: typical chest pain, pericardial friction rub, suggestive ECG changes, and a new or worsening pericardial effusion (5). There are four stages of ECG changes in pericarditis. Stage 1 includes widespread ST elevation and PR depression with reciprocal changes in aVR. Stage 2 includes T wave flattening. Stage 3 includes T wave inversion. Stage 4 includes normalization of the ECG (1). Distinguishing pericarditis and ST-elevation myocardial infarction (STEMI) can be challenging but is clinically important. Distinguishing characteristics in the acute phase include widespread, concave ST elevation and widespread PR depression with PR elevation in lead aVR (6,7). One study found that PR depression in precordial and limb leads had a positive predictive value of 96.7% and a negative predictive value of 90% for distinguishing myopericarditis from STEMI (6).
Conclusions: The ECG of Stage 1 pericarditis and STEMI can appear similar and may be difficult to distinguish. Important distinguishing characteristics include the clinical context, the ST segment morphology, and the progression of the ECG over time.