We present a clinical case of a patient, without previous cardiac history, admitted to the emergency department with chest pain at low probability for coronary artery disease.The first electrocardiogram showed high-risk changes that were mistakenly interpreted as normal; serial electrocardiograms did not show dynamic changes in STsegment or in the T wave.The patient remained asymptomatic and with hemodynamic stability.Ultrasensitive troponin was positive, and echocardiography reported a structurally healthy heart.Finally, the patient was submitted to diagnostic coronary angiography, evidencing involvement of the proximal anterior descending artery.After reviewing again the initial electrocardiogram, it revealed a high-risk pattern (the de Winter).