Figure 1.

Changes in mitochondrial function and structure occur throughout the progression of heart failure syndrome. As heart failure advances, vacuolar degeneration of the mitochondria becomes evident, along with increased membrane permeability, altered biochemical substrate utilization, and heightened production of free radicals. Although defensive mechanisms increase in response to these changes, they eventually become insufficient to prevent the impending decompensation as the syndrome worsens. Ultimately, the heart’s defenses are overwhelmed, leading to failure. The fort fell. p: preserved, r: reduced, ↑: increase, ↓: decrease, ↑↑: bigger increase, ↓↓: bigger decrease, ↓↓↓ much bigger decrease.