Final answer:
Elevated ST segments observed on an ECG during an exercise stress test are indicative of acute myocardial injury, which is a sign of a possible ST-elevation myocardial infarction (STEMI).
Step-by-step explanation:
When a technician observes elevated ST segments on an exercise stress test ECG, these findings are typically indicative of acute myocardial injury. This is known as an ST-elevated myocardial infarction, or STEMI, which requires immediate medical attention. Elevated ST segments are not generally expected ECG changes as a result of running, nor are they indicative of hypokalemia or signs of a pulmonary embolism, therefore the correct answer is they are signs of acute myocardial injury.