NBE Transthoracic Echocardiography 5 — Questions and Answers
Question 1: Which TTE finding is characteristic of an ostium secundum atrial septal defect (ASD)?
- Dropout in the inlet atrial septum with left-to-right shunt
- Dropout in the fossa ovalis region with right ventricular volume overload (Correct answer)
- Hypermobile atrial septum without shunting
- Premature closure of the foramen ovale
Correct answer: Dropout in the fossa ovalis region with right ventricular volume overload
Ostium secundum ASD appears as a central defect in the fossa ovalis with left-to-right shunting and consequent RV volume overload on TTE.
Question 2: In a patient with dilated cardiomyopathy, which diastolic pattern on mitral inflow Doppler is associated with the worst prognosis?
- Impaired relaxation pattern (E/A < 1)
- Pseudonormal pattern (E/A 1–2)
- Restrictive filling pattern (E/A > 2, short DT) (Correct answer)
- Normal filling pattern (E/A 1–2, normal DT)
Correct answer: Restrictive filling pattern (E/A > 2, short DT)
A restrictive filling pattern (E/A > 2, deceleration time < 150 ms) in DCM indicates severely elevated filling pressures and portends the poorest prognosis.
Question 3: Which condition is most likely when TTE reveals a linear echogenic structure in the right atrium moving independently of the atrial walls?
- Atrial thrombus
- Chiari network or Eustachian valve variant (Correct answer)
- Pacemaker lead perforation
- Right atrial myxoma
Correct answer: Chiari network or Eustachian valve variant
A Chiari network is a remnant of the right valve of the sinus venosus — a mobile, filamentous structure in the RA that is a normal variant.
Question 4: When performing TTE on a patient post-cardiac surgery with a prosthetic mechanical mitral valve, which Doppler parameter is most useful for detecting valve obstruction?
- Peak transmitral velocity and pressure half-time (Correct answer)
- Color Doppler regurgitant jet area
- Tissue Doppler of the mitral annulus
- M-mode of the posterior leaflet
Correct answer: Peak transmitral velocity and pressure half-time
Elevated peak transmitral velocity and prolonged PHT (≥ 130 ms) indicate increased resistance across the prosthetic valve, suggesting obstruction or pannus.
Question 5: Which echocardiographic criterion is used to define a positive bubble study (agitated saline contrast) for patent foramen ovale (PFO)?
- Any bubble appearing in the left heart within 5 cardiac cycles
- ≥ 3 bubbles in the left heart within 3 cardiac cycles of right atrial opacification (Correct answer)
- Bubbles appearing only during Valsalva maneuver
- Continuous left-to-right bubble transit
Correct answer: ≥ 3 bubbles in the left heart within 3 cardiac cycles of right atrial opacification
A positive bubble study for PFO requires ≥ 3 microbubbles appearing in the left heart within 3 cardiac cycles of right atrial opacification, especially with Valsalva.
Question 6: A patient has an aortic stenosis with a mean gradient of 45 mmHg but a calculated AVA of 0.7 cm². LVEF is 35%. This scenario is best described as:
- Moderate aortic stenosis with preserved EF
- Classic severe aortic stenosis
- Low-flow, low-gradient severe aortic stenosis (Correct answer)
- Pseudo-severe aortic stenosis
Correct answer: Low-flow, low-gradient severe aortic stenosis
Low EF reduces stroke volume and transvalvular flow, underestimating the gradient despite a truly small AVA — this is low-flow, low-gradient severe AS.
Question 7: Which TTE view provides the best assessment of the right ventricular free wall for arrhythmogenic right ventricular cardiomyopathy (ARVC)?
- Apical four-chamber (Correct answer)
- Parasternal long-axis
- Subcostal four-chamber
- Suprasternal notch view
Correct answer: Apical four-chamber
The apical four-chamber view offers the longest axis of the RV free wall, enabling detection of dilation, wall motion abnormalities, and aneurysms seen in ARVC.
NBE Transthoracic Echocardiography 5
Which TTE finding is characteristic of an ostium secundum atrial septal defect (ASD)?