NBE Stress Echocardiography 2 — Questions and Answers
Question 1: Which wall motion scoring index (WMSI) value indicates significant ischemia during stress echocardiography?
- WMSI > 1.0
- WMSI > 1.5 (Correct answer)
- WMSI > 2.0
- WMSI > 2.5
Correct answer: WMSI > 1.5
A WMSI greater than 1.5 is considered significant, as scores above this threshold indicate extensive wall motion abnormalities suggestive of ischemia.
Question 2: During dobutamine stress echo, which finding in a previously akinetic segment indicates myocardial viability?
- Worsening akinesis at peak dose
- Biphasic response with improvement at low dose and deterioration at peak dose (Correct answer)
- Persistent akinesis throughout all doses
- Development of dyskinesis at low dose
Correct answer: Biphasic response with improvement at low dose and deterioration at peak dose
A biphasic response (improvement at low-dose dobutamine followed by worsening at peak dose) is the classic marker of viable but ischemic myocardium.
Question 3: What is the recommended imaging protocol when using exercise stress echocardiography on a treadmill?
- Images acquired during peak exercise only
- Images acquired at rest and immediately post-exercise within 60–90 seconds (Correct answer)
- Images acquired only at rest before exercise
- Images acquired at 3-minute intervals during exercise
Correct answer: Images acquired at rest and immediately post-exercise within 60–90 seconds
Post-exercise images must be acquired within 60–90 seconds because wall motion abnormalities resolve rapidly after exercise cessation.
Question 4: Which pharmacological agent is used to reverse the effects of dobutamine during stress echocardiography?
- Atropine
- Adenosine
- Metoprolol (esmolol) (Correct answer)
- Nitroglycerin
Correct answer: Metoprolol (esmolol)
Beta-blockers such as esmolol or metoprolol are used to reverse tachycardia and other adverse effects of dobutamine.
Question 5: A new regional wall motion abnormality during stress echocardiography involves the anterior wall and apex. Which coronary artery territory does this most likely represent?
- Right coronary artery (RCA)
- Left circumflex artery (LCx)
- Left anterior descending artery (LAD) (Correct answer)
- Obtuse marginal branch
Correct answer: Left anterior descending artery (LAD)
The LAD supplies the anterior wall, apex, and anteroseptal segments, so ischemia in these regions implicates the LAD territory.
Question 6: In stress echocardiography, what does 'ischemic cascade' refer to?
- Sequence: ECG changes → perfusion defect → wall motion abnormality → symptoms
- Sequence: perfusion defect → wall motion abnormality → ECG changes → symptoms (Correct answer)
- Sequence: symptoms → ECG changes → perfusion defect → wall motion abnormality
- Sequence: wall motion abnormality → perfusion defect → ECG changes → symptoms
Correct answer: Sequence: perfusion defect → wall motion abnormality → ECG changes → symptoms
The ischemic cascade begins with perfusion abnormalities, followed by diastolic dysfunction, then wall motion abnormalities, then ECG changes, and finally symptoms.
Question 7: What is the significance of an augmented ejection fraction (EF) during low-dose dobutamine stress echo in a patient with reduced resting EF?
- Indicates fixed scar with no viable tissue
- Suggests viable myocardium with potential for functional recovery after revascularization (Correct answer)
- Confirms severe coronary artery disease requiring urgent intervention
- Indicates normal cardiac response with no further workup needed
Correct answer: Suggests viable myocardium with potential for functional recovery after revascularization
An EF augmentation with low-dose dobutamine indicates contractile reserve, suggesting viable myocardium that may recover function after revascularization.
NBE Stress Echocardiography 2
Which wall motion scoring index (WMSI) value indicates significant ischemia during stress echocardiography?