Abnormal Q waves may disappear after myocardial infarction (heart attack). Hours after myocardial infarction, especially in ST-segment elevation myocardial infarction, pathologic Q waves appear on the electrocardiogram within a few hours to 2 days, and the Q waves stabilize within 3 to 4 days, with the theory that necrotic waves will persist. With the shrinkage of scar tissue and compensatory hypertrophy of the surrounding myocardium, its extent may be significantly reduced after several years, especially in small infarcts, and the abnormal Q wave may even disappear. In general, pathologic Q waves are permanently present in 70% to 80% of cases, and the presence of abnormal Q waves is often indicative of old myocardial infarction. Both ST-segment elevation infarcts and non-ST-segment elevation infarcts can evolve into Q-wave or non-Q-wave infarcts without timely intervention. Chest pain often occurs during myocardial infarction, so if you have anterior heart pain, you should be alerted to this disease, and it is recommended that you seek medical treatment as soon as possible.