This is the definitive test for timing.
A patient presenting with Q waves and normalized ST segments could, in rare instances, be in a later stage of an acute event that occurred hours ago, or they may have a "completed" infarction where the ST elevation has resolved spontaneously. This requires immediate clinical correlation. anterior infarction age undetermined
If a patient presents with chest pain and this ECG finding, it is not sufficient to rule out acute coronary syndrome. Serial ECGs and troponin measurements are mandatory, as the patient could have an acute reinfarction or a chronic finding with an unrelated pain etiology. This is the definitive test for timing