The Masquerade of Myocardial Infarction as Gastroenteritis: A Diagnostic Challenge.

Acute coronary syndrome (ACS) can present with varied symptomatology, often deviating from classic presentations, particularly in patients without the characteristic chest pain. This case report describes an ST-elevation myocardial infarction (STEMI) that closely mimicked acute gastroenteritis, illustrating the challenges of differential diagnosis in atypical ACS presentations. We present the case of a 65-year-old Japanese male with a history of hypertension and dyslipidemia who arrived at the emergency department with acute abdominal pain, vomiting, diarrhea, and fever, symptoms suggesting viral gastroenteritis. The absence of chest pain diverted initial clinical suspicion away from cardiac causes. However, cardiovascular risk factors and a gallop rhythm prompted further cardiovascular evaluation. Subsequent blood tests and electrocardiogram findings suggested an acute myocardial infarction, later confirmed by coronary angiography as STEMI due to a 90% stenosis in the right coronary artery, which was successfully treated with percutaneous coronary intervention. The presentation of myocardial infarction can vary, with non-chest pain symptoms such as vomiting and fever occasionally leading the clinical picture, which may result in diagnostic delays and worsened prognosis. This case was particularly challenging due to the presence of all four symptoms typically associated with gastroenteritis, as well as the sequence of symptom onset being atypical for gastrointestinal diseases. This case exemplifies the need for a high degree of clinical suspicion for ACS in patients with atypical presentations, such as those mimicking gastroenteritis, to prevent misdiagnosis and ensure prompt and appropriate management, especially in patients with known cardiovascular risk factors.