In the context of aortic valve stenosis, what happens to the left ventricular myocardium and chamber volume?

In the context of aortic valve stenosis, what happens to the left ventricular myocardium and chamber volume?

• A. Increased thickness in the myocardium and decreased chamber volume
• B. Decreased thickness and increased chamber volume
• C. Increased thickness with increased chamber volume
• D. No change

Answer: (A)

Chronic pressure overload from aortic valve stenosis drives the left ventricle to thicken its wall in a process called concentric hypertrophy. When the ventricle has to push against a narrowed aortic valve, it increases pressure, and the heart adapts by adding sarcomeres in parallel, which thickens the myocardium without a proportional increase in chamber size. This thicker wall helps normalize wall stress (per the idea behind Laplace’s law), while the LV cavity becomes smaller, so the chamber volume decreases. Because the problem is primarily pressure overload, not volume overload, dilation of the chamber (increased volume) is not the typical response. The result is increased myocardial thickness with a reduced chamber volume, and diastolic filling can become impaired due to the stiffer ventricle, though systolic function may stay preserved early on.

Chronic pressure overload from aortic valve stenosis drives the left ventricle to thicken its wall in a process called concentric hypertrophy. When the ventricle has to push against a narrowed aortic valve, it increases pressure, and the heart adapts by adding sarcomeres in parallel, which thickens the myocardium without a proportional increase in chamber size. This thicker wall helps normalize wall stress (per the idea behind Laplace’s law), while the LV cavity becomes smaller, so the chamber volume decreases.

Because the problem is primarily pressure overload, not volume overload, dilation of the chamber (increased volume) is not the typical response. The result is increased myocardial thickness with a reduced chamber volume, and diastolic filling can become impaired due to the stiffer ventricle, though systolic function may stay preserved early on.