How does paradoxical low-flow low-gradient aortic stenosis differ from typical low-flow low-gradient AS?

How does paradoxical low-flow low-gradient aortic stenosis differ from typical low-flow low-gradient AS?

• A. Preserved LVEF with a small LV chamber and low stroke volume index
• B. Reduced LVEF with a small LV chamber
• C. Preserved LVEF with a large LV chamber
• D. Reduced LVEF with a large LV chamber

Answer: (A)

Paradoxical low-flow low-gradient aortic stenosis is defined by a preserved ejection fraction with a small left ventricular chamber that gives a low stroke volume, so the flow across the valve is limited and the gradient remains low despite severe stenosis. This contrasts with the typical low-flow low-gradient form, which occurs when the EF is reduced. The option describing preserved EF with a small LV chamber and a low stroke volume index captures the hallmark of the paradoxical pattern: the heart pumps less because the ventricle is small and stiff, so even a tight valve doesn’t generate a high pressure gradient. The other patterns—reduced EF, or preserved EF with a large LV chamber—don’t fit this specific combination of preserved systolic function and restricted LV filling that characterizes paradoxical LFLG AS.

Paradoxical low-flow low-gradient aortic stenosis is defined by a preserved ejection fraction with a small left ventricular chamber that gives a low stroke volume, so the flow across the valve is limited and the gradient remains low despite severe stenosis. This contrasts with the typical low-flow low-gradient form, which occurs when the EF is reduced. The option describing preserved EF with a small LV chamber and a low stroke volume index captures the hallmark of the paradoxical pattern: the heart pumps less because the ventricle is small and stiff, so even a tight valve doesn’t generate a high pressure gradient. The other patterns—reduced EF, or preserved EF with a large LV chamber—don’t fit this specific combination of preserved systolic function and restricted LV filling that characterizes paradoxical LFLG AS.