ACSM-EP Clinical Exercise Testing 5 — Questions and Answers
Question 1: Which criterion best confirms that true VO2max has been achieved during a maximal exercise test?
- HR exceeds 90% of age-predicted maximum
- VO2 plateaus (<150 mL/min increase) despite increasing workload (Correct answer)
- RER reaches 1.05
- Blood lactate exceeds 4 mmol/L
Correct answer: VO2 plateaus (<150 mL/min increase) despite increasing workload
A plateau in VO2 (<150 mL/min rise) despite increased workload is the gold-standard criterion for true VO2max, indicating maximal oxygen transport capacity.
Question 2: Cardiopulmonary exercise testing (CPET) is most valuable for differentiating exercise limitation caused by:
- Obesity versus deconditioning
- Cardiac versus pulmonary etiology (Correct answer)
- Type 1 versus Type 2 diabetes
- Peripheral vascular disease versus neuropathy
Correct answer: Cardiac versus pulmonary etiology
CPET simultaneously measures ventilation, gas exchange, and cardiovascular responses, allowing clinicians to distinguish cardiac from pulmonary causes of exertional dyspnea.
Question 3: During a field-based VO2max estimation using the 1.5-mile run test, which factor most strongly affects result accuracy?
- Ambient temperature
- Subject's pacing strategy (Correct answer)
- Type of footwear worn
- Time of day the test is performed
Correct answer: Subject's pacing strategy
Pacing is critical in time-trial field tests; starting too fast causes early fatigue and underestimates VO2max, while starting too slow produces an overestimate.
Question 4: A patient on digoxin therapy shows ST-segment depression at rest. During exercise testing, additional ST depression develops. The correct interpretation is:
- The additional depression confirms ischemia because digoxin does not affect ST segments
- Digoxin can cause ST depression at rest and during exercise, making ischemia interpretation unreliable (Correct answer)
- Digoxin-induced changes reverse with exercise, so exercise ST depression is diagnostic
- The test should be repeated without digoxin before any interpretation
Correct answer: Digoxin can cause ST depression at rest and during exercise, making ischemia interpretation unreliable
Digoxin produces ST-segment changes at rest and exaggerates them during exercise, confounding ischemia interpretation and lowering test specificity.
Question 5: What is the recommended lead configuration for detecting ST-segment changes during a standard clinical exercise test?
- Single-lead II monitoring only
- 3-lead system (I, II, III)
- 12-lead ECG system (Correct answer)
- V5 and aVF combination only
Correct answer: 12-lead ECG system
A full 12-lead ECG provides the greatest sensitivity for detecting regional ischemic ST changes during exercise testing.
Question 6: Which statement accurately describes the relationship between exercise testing sensitivity and specificity for detecting CAD?
- Higher sensitivity always yields higher specificity
- Increasing the ST depression threshold for a positive test increases sensitivity but decreases specificity
- Increasing the ST depression threshold for a positive test decreases sensitivity but increases specificity (Correct answer)
- Sensitivity and specificity are not affected by the diagnostic criterion chosen
Correct answer: Increasing the ST depression threshold for a positive test decreases sensitivity but increases specificity
Raising the ST threshold (e.g., from 1 mm to 2 mm) reduces false positives and increases specificity, but misses more true positives, lowering sensitivity.
Question 7: In a symptom-limited exercise test for a post-MI patient 4 weeks after discharge, which endpoint is most appropriate to use?
- Achieve 85% of age-predicted maximum HR
- Onset of moderate angina (4/10 on angina scale) or significant ST changes (Correct answer)
- Achieve a target of 5 METs regardless of symptoms
- Continue until volitional exhaustion like a healthy subject
Correct answer: Onset of moderate angina (4/10 on angina scale) or significant ST changes
Post-MI submaximal or symptom-limited tests are stopped at the onset of moderate angina or significant ischemic ECG changes to minimize risk in a recently infarcted myocardium.
ACSM-EP Clinical Exercise Testing 5
Which criterion best confirms that true VO2max has been achieved during a maximal exercise test?