Therapeutic Management of Low-Gradient Aortic Stenosis

According to current guidelines, 1–3 severe aortic stenosis (AS) is defined by a mean gradient >40 mm Hg, a peak aortic jet velocity >4 m/s, and an aortic valve area <1 cm2. However, the evaluation of AS severity is often rendered more complex by the concomitance of low gradient/velocity (ie, <40 mm Hg/<4 m/s) and small aortic valve area (ie, ≤1 cm2), which is also referred as discordant grading or low-gradient severe AS. In the Schrödinger experiment, the Copenhagen theoretical interpretation of quantum mechanics implies that after a while, the cat placed in a sealed box with a flask of poison, and a radioactive source, is simultaneously alive and dead, which is referred as quantum superposition and is, of course, impossible. Similarly, AS of a patient with low-gradient AS cannot be simultaneously severe and non-severe.