Which of the following is NOT listed as an adaptive mechanism contributing to HF progression?

• A. Increased preload
• B. Neurohumoral activation
• C. Decreased afterload
• D. Fluid retention

Answer: (C)

The heart’s compensatory responses in heart failure that end up harming the heart include increasing preload, activating neurohumoral systems, and fluid retention. Increasing preload, driven by fluid retention and enhanced venous return, stretches the ventricle and initially supports stroke volume, but chronically this dilation worsens dysfunction and promotes remodeling. Neurohumoral activation—especially the sympathetic system and the renin-angiotensin-aldosterone system—helps maintain blood pressure and perfusion in the short term, but over time it causes vasoconstriction, increased afterload, myocardial remodeling, fibrosis, and further decline in cardiac function. Fluid retention directly raises circulating volume, heightening preload and edema, which adds congestion and strain on the heart.

Decreasing afterload, on the other hand, would lessen the resistance the heart has to pump against and is generally beneficial, improving forward flow and reducing myocardial work. It is not considered an adaptive mechanism driving progression; rather, therapies that reduce afterload are used to improve symptoms and outcomes.