CMC Technology & Digital Tools 3 — Questions and Answers
Question 1: Optical coherence tomography (OCT) in interventional cardiology provides superior image resolution compared to intravascular ultrasound (IVUS) primarily because it uses:
- Near-infrared light rather than sound waves, achieving 10-15 μm resolution (Correct answer)
- Higher frequency ultrasound transducers above 60 MHz
- Dual-frequency acoustic technology
- Fluorescent contrast agents that bind to plaque components
Correct answer: Near-infrared light rather than sound waves, achieving 10-15 μm resolution
OCT uses near-infrared light to achieve 10–15 μm resolution, approximately 10× greater than IVUS, enabling visualization of thin-cap fibroatheroma.
Question 2: A cardiac implantable electronic device (CIED) remote monitoring alert fires for a patient showing 6 hours of atrial high-rate episodes at 190 bpm. The MOST appropriate next action is:
- Contact the patient to assess symptoms and review device logs before deciding on anticoagulation changes (Correct answer)
- Immediately start anticoagulation without contacting the patient
- Reprogram the device to a higher atrial detection rate
- Schedule elective device replacement
Correct answer: Contact the patient to assess symptoms and review device logs before deciding on anticoagulation changes
Sub-clinical atrial fibrillation detected by CIEDs requires clinical correlation including symptom assessment and stroke risk evaluation before therapeutic changes.
Question 3: When using speckle-tracking echocardiography (STE) to assess left ventricular function, global longitudinal strain (GLS) of -14% in a patient with preserved ejection fraction suggests:
- Subclinical myocardial dysfunction despite normal LVEF (Correct answer)
- Hyperdynamic function with supranormal contractility
- Normal LV function within reference ranges
- Artifact from inadequate image quality
Correct answer: Subclinical myocardial dysfunction despite normal LVEF
Normal GLS is typically more negative than -18%; a value of -14% indicates reduced myocardial deformation consistent with subclinical dysfunction.
Question 4: In a cardiac catheterization lab, the term 'DICOM' refers to:
- Digital Imaging and Communications in Medicine, the standard format for storing and transmitting medical images (Correct answer)
- A hemodynamic monitoring software platform
- The radiation dose reporting protocol for cath lab procedures
- A contrast injection protocol for coronary angiography
Correct answer: Digital Imaging and Communications in Medicine, the standard format for storing and transmitting medical images
DICOM is the universal standard for handling, storing, and transmitting medical imaging data including cath lab fluoroscopy and echo images.
Question 5: A wearable cardioverter-defibrillator (WCD) is MOST appropriately prescribed for:
- A patient with newly diagnosed cardiomyopathy and LVEF 25% awaiting reassessment of LVEF after 3 months of GDMT (Correct answer)
- A patient with permanent atrial fibrillation and LVEF 45%
- A patient with stable CAD and LVEF 50% pre-CABG
- A patient with hypertrophic cardiomyopathy and normal LVEF
Correct answer: A patient with newly diagnosed cardiomyopathy and LVEF 25% awaiting reassessment of LVEF after 3 months of GDMT
WCDs bridge the period before ICD implantation in patients with newly diagnosed low LVEF who may recover function with GDMT.
Question 6: During an exercise stress test, the Bruce protocol treadmill software calculates metabolic equivalents (METs). A patient achieving 10 METs indicates:
- Excellent functional capacity associated with low cardiovascular mortality risk (Correct answer)
- Poor functional capacity requiring further evaluation
- Borderline functional capacity suggesting moderate risk
- The test was submaximal and results are non-diagnostic
Correct answer: Excellent functional capacity associated with low cardiovascular mortality risk
Achieving ≥10 METs on a Bruce protocol indicates excellent functional capacity and confers a favorable prognosis regardless of other findings.
Question 7: Instantaneous wave-free ratio (iFR) differs from FFR in that it:
- Measures pressure ratio during the diastolic wave-free period without pharmacologic hyperemia (Correct answer)
- Requires adenosine infusion to achieve maximum hyperemia
- Uses Doppler flow velocity rather than pressure measurements
- Is calculated from coronary CT angiography data
Correct answer: Measures pressure ratio during the diastolic wave-free period without pharmacologic hyperemia
iFR measures the pressure ratio across a stenosis during a naturally occurring low-resistance period in diastole, eliminating the need for adenosine.
CMC Technology & Digital Tools 3
Optical coherence tomography (OCT) in interventional cardiology provides superior image resolution compared to intravascular ultrasound (IVUS) primarily because it uses: