Concentric hypertrophy is described as which?

• A. Chamber sizes stay the same, but left ventricular walls thicken in response to high resistance.
• B. Chamber sizes remain unchanged and walls thicken.
• C. Chamber size increases with wall thinning.
• D. The heart reduces its muscle mass.

Answer: (A)

Concentric hypertrophy occurs when the heart faces increased afterload or resistance, like with long-standing hypertension or aortic stenosis. In response, the heart adds sarcomeres in parallel, causing the ventricular walls to thicken. This thicker wall helps to normalize wall stress at higher pressures, so the chamber radius doesn’t need to enlarge; the result is preserved or even reduced chamber size with increased wall thickness. The option describes exactly this pattern: chamber sizes stay the same while the walls thicken in response to high resistance. Other patterns describe dilation with thinning of the walls (eccentric hypertrophy) or a loss of muscle, which do not fit concentric hypertrophy.