BACKGROUND Stress induced cardiomyopathy (SIC) is characterized by non-obstructive coronary arteries and characteristic ventricular apical ballooning. The exact pathogenesis of SIC is not well recognized. We present an unusual case of SIC that mimicked acute myopericarditis and discuss the effect of this masquerading presentation of SIC in recognizing pathophysiological association between myopericarditis and SIC and limitations of current diagnostic criteria. CASE REPORT A 47-year-old female presented with flu-like illness and pleuritic chest pain. An electrocardiogram (ECG) showed diffuse PR depressions and ST elevations, troponin 5 ng/mL, hemoglobin 14.2 mg/dL, leukocytosis (white blood cell count of 15.1×103/uL) and erythrocyte sedimentation rate (ESR) of 22.4 mm/hour. Echocardiogram showed reduced ejection fraction (EF) with apical ballooning. Catheterization showed non-obstructive coronary disease. The patient was given colchicine and ibuprofen for 1 day with symptom resolution over the next 2 days and repeat echocardiogram with preserved EF. Troponin trended down to 3.24 ng/mL and 0.44 ng/mL, 6 hours apart. ECG showed resolution of PR depressions and subsequent T wave inversions in 1, AVl, V1-V6 by day 3. The diagnosis of myopericarditis was favored by viral prodrome, fever, pleuritic pain, pericardial rub, ECG findings, and elevated ESR. History of emotional stress, characteristic ballooning of left ventricle apex with rapid resolution favored SIC. CONCLUSIONS This case showed that SIC and myocarditis need not be mutually exclusive and differentiating clinically between these 2 entities can be difficult. Alternatively, SIC can accompany other cardiac conditions like myocardial infarction, pericarditis, and myocarditis making diagnosis and management challenging. Clinicians need to be cautious while making this differentiation as duration and type of therapy may be significantly different. SIC can be considered a variant of regional inflammatory myocarditis wherein pericarditis may result secondary to extension of myocardial inflammation to overlying pericardium. The current Mayo Clinic criteria for diagnosis of SIC appears to be outdated, not accounting for such atypical presentations, and therefore needs to be revised.