Figure 1

Time course of phases of wound healing, infarct scar formation, and cardiac fibrosis. The four phases of wound healing are hemostasis, inflammation, cell proliferation (including of fibroblasts), and ECM synthesis/remodeling and scar formation. The precise timing of these events is variable (indicated by the grayscale gradients), depending on the severity of the wound and the presence of exacerbating factors (for example, infection). Ideally, wounds will heal fully, but scars may persist for many years or the life of the individual (dashed lines). Infarct scar formation begins with removal of dead cells (not shown) and is followed by similar phases of inflammation, proliferation, and scar formation/remodeling. Unlike in wound healing, myofibroblasts may persist in the scar for years, leading to long-term remodeling. In interstitial cardiac fibrosis, the precise timing of the initiating event may be impossible to determine, and the phases of cell proliferation and ECM remodeling may continue over spans of years. An inflammatory component may also be present (dashed box), depending on the nature of the underlying insult.