CCI Cardiac Stress Testing Protocols 4 — Questions and Answers
Question 1: Which lead configuration is considered most sensitive for detecting stress-induced ischemic ST changes during exercise ECG testing?
- Lead I and aVL only
- Leads V4, V5, and V6 (Correct answer)
- Leads II, III, and aVF
- Lead aVR and V1
Correct answer: Leads V4, V5, and V6
The lateral precordial leads V4, V5, and V6 are most sensitive for detecting subendocardial ischemia during stress testing.
Question 2: A patient with known Wolff-Parkinson-White (WPW) syndrome is referred for stress testing. Which statement about ST changes in WPW during exercise is correct?
- ST changes in WPW are highly specific for ischemia during exercise
- WPW causes baseline ST abnormalities that make ECG interpretation unreliable during stress (Correct answer)
- Exercise testing is absolutely contraindicated in all WPW patients
- Rate-related ST changes in WPW normalize at higher heart rates, improving specificity
Correct answer: WPW causes baseline ST abnormalities that make ECG interpretation unreliable during stress
The delta wave and secondary ST-T changes in WPW render ECG-based ischemia assessment unreliable; imaging modalities should be added for diagnostic purposes.
Question 3: What is the minimum recommended systolic blood pressure threshold at which exercise stress testing should be terminated to prevent hypertensive emergency?
- 180 mmHg
- 200 mmHg
- 220 mmHg (Correct answer)
- 250 mmHg
Correct answer: 220 mmHg
A systolic BP exceeding 220 mmHg during exercise is a relative indication to stop; >250 mmHg is considered a threshold for mandatory termination to prevent hypertensive crisis.
Question 4: During a nuclear stress test using regadenoson, a patient develops a new fixed perfusion defect compared to rest images. What does a fixed defect most likely represent?
- Reversible ischemia in the territory of a stenotic artery
- Prior myocardial infarction with scar tissue (Correct answer)
- Normal variant artifact from diaphragmatic attenuation
- Hibernating myocardium with potential for recovery
Correct answer: Prior myocardial infarction with scar tissue
A fixed (non-reversible) perfusion defect present on both stress and rest images indicates infarcted, non-viable myocardium.
Question 5: In stress echocardiography, which wall motion abnormality pattern is most consistent with multi-vessel ischemia rather than single-vessel disease?
- New hypokinesis isolated to the anterior wall only
- New akinesis of the inferior wall only at peak stress
- Stress-induced wall motion abnormalities in multiple non-contiguous territories (Correct answer)
- Worsening of a known inferior wall motion abnormality at low dose dobutamine
Correct answer: Stress-induced wall motion abnormalities in multiple non-contiguous territories
New wall motion abnormalities in multiple non-contiguous coronary territories at peak stress indicate multi-vessel disease with widespread ischemia.
Question 6: What phenomenon is observed when a stress echocardiogram shows improved wall motion in a hypokinetic segment at low-dose dobutamine (5-10 mcg/kg/min) that worsens at high-dose dobutamine?
- Hibernating myocardium — indicates viability and potential for recovery with revascularization (Correct answer)
- Stunned myocardium — expected to recover spontaneously without intervention
- Scar tissue — fixed abnormality with no contractile reserve
- Coronary steal — indicates severe collateral-dependent circulation
Correct answer: Hibernating myocardium — indicates viability and potential for recovery with revascularization
The biphasic response (improvement at low dose, deterioration at high dose) is the hallmark of hibernating myocardium, indicating viability and benefit from revascularization.
Question 7: Which patient would be LEAST appropriate for a standard symptom-limited maximal exercise treadmill test without imaging?
- 45-year-old male with atypical chest pain and normal resting ECG
- 60-year-old female with typical angina and normal baseline ECG
- 55-year-old male with prior CABG and baseline LBBB on ECG (Correct answer)
- 50-year-old with hypertension referred for preoperative cardiac clearance
Correct answer: 55-year-old male with prior CABG and baseline LBBB on ECG
LBBB on baseline ECG causes false-positive ST changes during exercise, making ECG-only stress testing uninterpretable and necessitating imaging adjuncts.
CCI Cardiac Stress Testing Protocols 4
Which lead configuration is considered most sensitive for detecting stress-induced ischemic ST changes during exercise ECG testing?