Final answer:
The ST segment is disturbed by myocardial infarction, and its elevation or depression can indicate an acute MI.
Step-by-step explanation:
The ECG line disturbed by myocardial infarction is the ST segment.
The ST segment represents the period between ventricular depolarization (QRS complex) and repolarization (T wave). An elevation or depression of the ST segment from the baseline can indicate myocardial infarction. An elevation is often seen in patients with an acute myocardial infarction (MI).