Q26 / 110
On VA-ECMO, echo shows a severely dilated LV, spontaneous echo contrast, and no aortic valve opening. Which immediate complication is most concerning?
Correct answer: B — LV thrombus formation
On VA-ECMO, a severely dilated LV with spontaneous echo contrast and no aortic valve opening is most concerning for LV thrombus formation. In addition, there is high risk of aortic root thrombus. This pattern reflects severe blood stasis and is one reason active unloading should not be delayed.
Board pearl: Closed aortic valve plus LV smoke means high risk of LV and aortic root thrombus.
On VA-ECMO, a severely dilated LV with spontaneous echo contrast and no aortic valve opening is most concerning for LV thrombus formation. In addition, there is high risk of aortic root thrombus. This pattern reflects severe blood stasis and is one reason active unloading should not be delayed.
Board pearl: Closed aortic valve plus LV smoke means high risk of LV and aortic root thrombus.
Q27 / 110
Despite excellent VA-ECMO flows, a patient develops worsening pulmonary edema. What mechanism is most likely?
Correct answer: B — Elevated left atrial pressure secondary to LV distention
ECMO-related LV afterload can raise LV and LA pressures, producing hydrostatic pulmonary edema. A is not the usual mechanism. C causes impaired gas exchange but does not itself explain hydrostatic edema. D is not the principal left-sided mechanism described.
Board pearl: Adequate ECMO flow does not guarantee adequate LV decompression.
ECMO-related LV afterload can raise LV and LA pressures, producing hydrostatic pulmonary edema. A is not the usual mechanism. C causes impaired gas exchange but does not itself explain hydrostatic edema. D is not the principal left-sided mechanism described.
Board pearl: Adequate ECMO flow does not guarantee adequate LV decompression.
Q28 / 110
Which is a direct LV unloading strategy?
Correct answer: B — Impella placement
Impella physically removes blood from the LV. Vasodilators and inotropes influence loading or contractility indirectly. Increasing ECMO flow commonly increases effective LV afterload and may worsen distention.
Board pearl: Not every therapy that improves output directly unloads the LV.
Impella physically removes blood from the LV. Vasodilators and inotropes influence loading or contractility indirectly. Increasing ECMO flow commonly increases effective LV afterload and may worsen distention.
Board pearl: Not every therapy that improves output directly unloads the LV.
Q29 / 110
Why can increasing peripheral VA-ECMO flow worsen LV distention in profound LV failure?
Correct answer: B — It increases retrograde aortic pressure and effective LV afterload
More retrograde aortic flow raises the pressure against which the LV must eject. A is not the principal mechanism. C is not inevitable or central. D is the opposite of what generally occurs as circuit flow rises.
Board pearl: More ECMO flow is not always better.
More retrograde aortic flow raises the pressure against which the LV must eject. A is not the principal mechanism. C is not inevitable or central. D is the opposite of what generally occurs as circuit flow rises.
Board pearl: More ECMO flow is not always better.
Q30 / 110
Why should favorable outcomes with early unloading in the Schrage registry be interpreted cautiously?
Correct answer: B — It was observational and susceptible to selection bias and residual confounding
Favorable outcomes with early unloading in the Schrage registry should be interpreted cautiously because the study was observational and susceptible to selection bias, treatment-timing bias, and residual confounding. See question 23: lower mortality was observed despite higher complication rates, so interpretation must remain cautious rather than triumphal.
Board pearl: Favorable observational outcomes do not erase the higher complication burden.
Favorable outcomes with early unloading in the Schrage registry should be interpreted cautiously because the study was observational and susceptible to selection bias, treatment-timing bias, and residual confounding. See question 23: lower mortality was observed despite higher complication rates, so interpretation must remain cautious rather than triumphal.
Board pearl: Favorable observational outcomes do not erase the higher complication burden.