What is a key consequence of neurohormonal activation in heart failure?

• A. Activation of RAAS and sympathetic nervous system leads to vasoconstriction, sodium and water retention, and ventricular remodeling.
• B. Decreased aldosterone production promotes diuresis.
• C. Parasympathetic stimulation increases heart rate.
• D. Natriuretic peptides dominate to cause fluid retention.

Answer: (A)

When the heart isn’t pumping effectively, the body activates neurohormonal systems to preserve blood pressure and perfusion. The renin-angiotensin-aldosterone system and the sympathetic nervous system drive vasoconstriction and promote sodium and water retention. This combination raises preload and afterload, which momentarily helps maintain circulation but over time worsens congestion and pressures the heart to remodel—changing the size, shape, and function of the ventricles. This remodeling is a key factor in the progressive decline seen in heart failure.

Aldosterone production isn’t decreased in this situation; it’s increased, which promotes more sodium and water retention rather than diuresis. The parasympathetic system does not drive heart rate up here; the pattern is sympathetic activation with reduced parasympathetic influence. Natriuretic peptides are released to promote natriuresis and diuresis to counterbalance fluid overload, not to cause fluid retention, and their effects are often overwhelmed in chronic heart failure.