What ST-segment change is a relative indication to stop exercise testing?

What ST-segment change is a relative indication to stop exercise testing?

• A. Marked horizontal or downsloping ST displacement >2 mm, measured 60-80 ms after the J point in suspected ischaemia
• B. ST elevation of 1 mm
• C. ST elevation 3 mm
• D. No ST change

Answer: (C)

During an exercise stress test, ST-segment changes reveal how well the heart is tolerating increased demand. A sudden, marked ST-segment elevation of about 3 mm (0.30 mV), measured roughly 60 to 80 milliseconds after the J point in the leads showing elevation, signals a dramatic disturbance in myocardial electrical activity. This pattern suggests significant ischemia or injury to the heart muscle and indicates the patient may be at high risk if the test continues. Because of that elevated risk, stopping the test is warranted even if other signs aren’t as severe. A large horizontal or downsloping ST depression (>2 mm) is also a warning sign of ischemia, and would typically lead to stopping, but the question highlights the more dangerous finding—substantial ST elevation—as the reason to halt. A smaller elevation (1 mm) is less definitive and could reflect baseline variation or artifacts, and no change implies the patient is tolerating the test.

During an exercise stress test, ST-segment changes reveal how well the heart is tolerating increased demand. A sudden, marked ST-segment elevation of about 3 mm (0.30 mV), measured roughly 60 to 80 milliseconds after the J point in the leads showing elevation, signals a dramatic disturbance in myocardial electrical activity. This pattern suggests significant ischemia or injury to the heart muscle and indicates the patient may be at high risk if the test continues. Because of that elevated risk, stopping the test is warranted even if other signs aren’t as severe.

A large horizontal or downsloping ST depression (>2 mm) is also a warning sign of ischemia, and would typically lead to stopping, but the question highlights the more dangerous finding—substantial ST elevation—as the reason to halt. A smaller elevation (1 mm) is less definitive and could reflect baseline variation or artifacts, and no change implies the patient is tolerating the test.