REN and Hyperglycemia: This inflammation-oxidative stress cycle is further amplified in the acute phase of AHF; acute hyperglycemia triggers rapid blood volume changes through osmotic diuresis, activating the renin-angiotensin-aldosterone system and the sympathetic nervous system, increasing inflammatory mediators’ release by 3–5 times, accelerating myocardial apoptosis and microcirculatory disorders, creating a “waterfall effect” of deteriorating cardiac function [44].