The heart, on the other hand, has the potential to grow new muscles and possibly heal itself. However, the pace of regeneration is so sluggish that it cannot repair the type of damage produced by a heart attack. As a result, the quick mending that occurs after a heart attack results in scar tissue instead of functional muscle tissue. The few cells that are able to repopulate the damaged area then produce even more scar tissue.
However, when tested in animals, stem cell therapy has shown promise in improving cardiac function after injury. Further research needs to be done on human subjects before any definitive conclusions can be made about its effectiveness for people who have had heart attacks, but it may be an option for future patients if proven safe and effective.
After a heart attack, the heart is unable to repair heart muscle, and lost cardiac muscle is replaced by scar tissue. As a result, the heart's incapacity to regenerate cardiac muscle, along with a predominant fibrotic damage response, remains a key basic barrier to treating heart disease. However many other cell types are present in the heart, including immune cells, blood vessels, and even skeletal muscle cells. It has been suggested that these other cell types contribute to the fibrotic damage response by releasing proteins that promote more collagen production by cardiac fibroblasts or induce apoptosis in cardiomyocytes. However, it is also possible that heart muscle cells play a role in this process through the release of cytokines or other factors.
Heart muscle cells do have the potential to replicate themselves. When injured, they will divide more frequently than usual to fill in the gap between damaged tissues. This ability is called regenerative capacity and it is found among some single-cell organisms like Hydra. Some vertebrate animals (including humans) can regenerate certain organs such as muscles or limbs, but not all tissues are capable of regeneration. The heart is a big organ made up of several different kinds of muscles that cannot be replaced once they are damaged.
At first glance, it might seem that heart muscle cells would never be able to recover from serious injury. However, scientists have discovered ways to activate the regenerative capacity of heart muscle cells under certain conditions.
Scar tissue does not contribute to cardiac contractile force, hence the remaining viable heart muscle has a higher hemodynamic burden. Over time, this can lead to increased fatigue and decreased performance of the heart.
Cardiac muscle can be regenerated through the proliferation and differentiation of adult cardiac stem cells or progenitor cells. Transplantation of stem cell-derived cardiomyocytes may one day be used as a replacement for damaged cardiac tissue.
Scientists have discovered another way in which the heart can regenerate: through maturation of existing cardiac muscle fibers. Studies in animals have shown that cardiac muscle can undergo hypertrophy (the growth of additional muscle cells) and fibrosis (the formation of excess scar tissue), processes similar to those that occur with muscle fiber regeneration after injury. These studies suggest that the heart may have the ability to regenerate itself through repeated bouts of damage and repair.
The human heart has limited regenerative capacity. A study published in 2004 showed that only a small number of myocardial cells are born each day in the human body. This means that the total number of cells in the heart remains relatively constant, and any loss of heart muscle must be made up by new cell growth or atrophy.
Heart muscle that has been injured by a heart attack recovers via the formation of scar tissue. Your cardiac muscle will normally take many weeks to recover. The duration is determined on the severity of your injury and your individual rate of healing. If you are being treated with medication to prevent further heart attacks, your time for recovery may be extended.
However, if the damage is severe or continuous, the heart muscle will not have a chance to heal. Then you will need surgery to replace it with healthy tissue.
The ability of damaged heart tissue to repair itself is an important factor in determining how much damage has been done to the heart and whether more serious problems are likely to develop.
Studies have shown that under certain conditions, heart muscle cells are able to divide and form new tissue. This process is called regeneration. Adult heart muscle does not normally replicate itself; instead, it grows through cell division of existing muscle cells or by adding extra layers of tissue. However, this ability can be activated even in very old people, including seniors who have reached their 80s and 90s.
In most cases, the body is not capable of healing completely after a heart attack. The damaged area of the heart will not regenerate fully, so additional damage is likely to occur.