CVT Stress Testing Protocols 3 — Questions and Answers
Question 1: Which ECG finding during stress testing is considered a POSITIVE test for ischemia under standard ACC/AHA criteria?
- 1 mm upsloping ST depression measured at J-point
- ≥1 mm horizontal or downsloping ST depression 80 ms after the J-point (Correct answer)
- T-wave peaking in V2 at peak exercise
- PR interval shortening by 20 ms
Correct answer: ≥1 mm horizontal or downsloping ST depression 80 ms after the J-point
Horizontal or downsloping ST depression of ≥1 mm measured 80 ms after the J-point is the standard positive criterion for exercise-induced ischemia.
Question 2: In dobutamine stress echocardiography, which dose range is typically used to achieve peak stress?
- 5–10 mcg/kg/min
- 20–40 mcg/kg/min (Correct answer)
- 50–60 mcg/kg/min
- 80–100 mcg/kg/min
Correct answer: 20–40 mcg/kg/min
Dobutamine is titrated from 10 mcg/kg/min up to 40 mcg/kg/min (with atropine added if needed) to achieve 85% of maximum predicted heart rate.
Question 3: A patient undergoing a Bruce protocol reaches Stage III. Approximately how many METs has this patient achieved?
- 4 METs
- 7 METs
- 10 METs (Correct answer)
- 13 METs
Correct answer: 10 METs
Stage III of the Bruce protocol (3.4 mph at 14% grade) corresponds to approximately 10 METs of oxygen consumption.
Question 4: What is the recommended minimum duration for the post-stress ECG monitoring period?
- 1 minute
- 3 minutes
- At least 6–8 minutes or until abnormalities resolve (Correct answer)
- 15 minutes
Correct answer: At least 6–8 minutes or until abnormalities resolve
Post-exercise monitoring should continue for at least 6–8 minutes or until ECG changes and symptoms fully resolve, as late findings are diagnostically important.
Question 5: Which heart rate target is used to define an adequate pharmacologic stress with regadenoson or adenosine for nuclear imaging?
- Achieving 85% of maximum predicted heart rate is required
- Heart rate response is NOT the endpoint; vasodilation itself is the stressor (Correct answer)
- 60 bpm sustained for 2 minutes
- Heart rate must double from baseline
Correct answer: Heart rate response is NOT the endpoint; vasodilation itself is the stressor
Vasodilator agents like adenosine and regadenoson induce coronary hyperemia directly and do not require a heart rate endpoint the way exercise or dobutamine testing does.
Question 6: During stress testing, ST elevation in leads without prior Q-waves (non-infarct territory) most likely represents:
- Benign early repolarization pattern
- Severe transmural ischemia or coronary spasm (Correct answer)
- Normal exercise-induced vagal response
- Electrode misplacement artifact
Correct answer: Severe transmural ischemia or coronary spasm
Exercise-induced ST elevation in non-Q-wave leads indicates severe transmural ischemia, often from critical proximal coronary stenosis or vasospasm, and is a test-stopping criterion.
Question 7: The Duke Treadmill Score incorporates which three variables for risk stratification?
- Age, sex, and resting ECG
- Exercise time, ST deviation, and angina index (Correct answer)
- Peak heart rate, blood pressure, and MET level
- Ejection fraction, wall motion score, and symptoms
Correct answer: Exercise time, ST deviation, and angina index
The Duke Treadmill Score = exercise time – (5 × ST deviation) – (4 × angina index), stratifying patients into low, intermediate, or high-risk categories.
CVT Stress Testing Protocols 3
Which ECG finding during stress testing is considered a POSITIVE test for ischemia under standard ACC/AHA criteria?