Aortic stenosis causes left ventricular hypertrophy

Steps:

• Aortic stenosis narrows the valve, increasing resistance to blood ejection from the left ventricle.
• The left ventricle compensates by contracting more forcefully, raising intraventricular pressure.
• Chronic pressure overload triggers hypertrophy, thickening the ventricular wall.
• Thickened wall impairs relaxation, reducing diastolic filling and enlarging the heart.

Why D is correct:

• According to cardiac physiology, sustained pressure overload from aortic stenosis induces concentric hypertrophy, leading to diastolic dysfunction as defined by impaired ventricular compliance.

Why the others are wrong:

• A: Describes mitral regurgitation, not aortic stenosis effects.
• B: Hypertrophy increases, not reduces, ventricular muscle; diastolic pressure is typically unaffected or elevated.
• C: Systolic pressure proximal to the stenosis rises; left ventricular filling volume remains normal.

Final answer: D