Severe Dengue Fever Complicated by Myocarditis Presenting as ST-Elevation Myocardial Infarction: A Case Report with Atypical Features

Abstract

Background: Dengue fever, a mosquito-borne viral illness, can rarely present with cardiac complications that mimic acute myocardial infarction. This case highlights the diagnostic challenge of dengue myocarditis presenting with ST segment elevation (STE) on electrocardiography (ECG).

Case Presentation: A 28 year old male presented with fever, chest pain, and dyspnea. Initial ECG showed inferior ST elevation and diffuse ST depression, highly suggestive of ST elevation myocardial infarction (STEMI). Echocardiography revealed preserved biventricular function without regional wall motion abnormalities. Emergent coronary angiography demonstrated normal coronary arteries. Laboratory testing confirmed acute dengue infection via positive PCR and serology (IgM/IgG), along with significant thrombocytopenia (57,000/μL) and elevated cardiac enzymes (peak Troponin I 8.5 ng/mL). The ST segment elevations resolved spontaneously within 24 hours, supporting a final diagnosis of acute dengue myocarditis.

Conclusion: This case underscores the critical importance of considering dengue myocarditis in differential diagnosis of STEMI in endemic regions, particularly in young, febrile patients without coronary risk factors. Accurate recognition prevents unnecessary interventions like thrombolysis and guides appropriate supportive management.