Hello, the changes of ST segment of ECG are generally easy to cause myocardial ischemia in clinic, which is more common in angina pectoris and coronary heart disease. 18 years old is less likely to have this situation, or it may be caused by arrhythmia and other reasons.

Suggestion:

My opinion is that you need to go to the hospital for a color Doppler ultrasound, a 24-hour dynamic electrocardiogram, a treadmill test and so on. And then consider whether treatment is needed.