Which compensatory mechanism is involved in both chronic heart failure and decompensated heart failure, leading to fluid retention and edema?

A. Increased systemic blood pressure – While systemic vasoconstriction may occur to maintain perfusion, it is a result of compensatory mechanisms like RAAS, not a primary mechanism leading to fluid retention and edema. B. Renin-angiotensin-aldosterone activation – RAAS leads to: Sodium and water retention via aldosterone Vasoconstriction via angiotensin II These changes increase intravascular volume, contributing to fluid overload and edema. C. Ventricular hypertrophy – This is a structural adaptation to increased workload (pressure overload), not directly responsible for fluid retention. D. Ventricular dilation – Dilation occurs as a result of chronic volume overload, not as a compensatory mechanism causing fluid retention.