Question

q: long - standing hypertension is the most common cause of heart failure. what is the pathological sequence that leads to the ventricles stiffness in this condition?
description: sys2 heart obj7c
a. aortic stenosis → volume overload → ventricular dilation.
b. pressure overload → left ventricular hypertrophy → myocardial fibrosis.
c. myocardial infarction → necrosis → ischemic cardiomyopathy.
d. coronary plaque rupture → coronary artery occlusion → hfref.

Explanation:

Long - standing hypertension causes pressure overload on the heart. This pressure overload leads to left ventricular hypertrophy (thickening of the ventricular wall). Over time, myocardial fibrosis (replacement of normal heart muscle tissue with fibrous tissue) occurs. Fibrous tissue is stiffer than normal heart muscle tissue, leading to ventricular stiffness.

• Option A: Aortic stenosis causes pressure overload, not volume overload. Ventricular dilation is more associated with volume overload (e.g., in mitral regurgitation) rather than the typical sequence in long - standing hypertension.
• Option C: Myocardial infarction (heart attack) is due to a lack of blood supply (ischemia) to the heart muscle, leading to necrosis. Ischemic cardiomyopathy is related to reduced heart function due to repeated myocardial infarctions, not the sequence in long - standing hypertension.
• Option D: Coronary plaque rupture and coronary artery occlusion are related to acute coronary syndromes (e.g., myocardial infarction), and HFrEF (heart failure with reduced ejection fraction) is a type of heart failure but not the pathological sequence for ventricular stiffness in long - standing hypertension.

Answer:

B. Pressure Overload → Left Ventricular Hypertrophy → Myocardial Fibrosis.