People with heart failure may have trouble breathing, walking, and having a normal life. Current treatments for heart failure are aimed at making the healthy heart tissue pump harder (e.g. digoxin). On the other hand, treatments largely ignore dead heart tissue because there A myocardial infarction, better known as a heart attack, occurs when blood flow through the coronary arteries to the heart is blocked. This usually occurs when a blood clot forms in a coronary artery. Since the heart is a highly active muscle, it requires a constant supply of oxygen and nutrients to maintain its pumping function. When the heart muscle is starved of oxygen, as is the case during myocardial infarction, heart cells become dysfunctional. If blood flow through the coronary arteries (which carries oxygen to the heart) is not restored soon after a heart attack begins, those dysfunctional heart cells will die.
When heart tissue has been destroyed by a heart attack, patients are usually left with poor heart function. This can lead to congestive heart failure. One way to determine whether someone who has had a heart attack has suffered lasting heart damage is to perform an echocardiogram, or simply an “echo.” By performing an echo, doctors can estimate the heart’s ability to pump blood by measuring left ventricular function.
has been no known way to rescue it. With the discovery and use of stem cells, however, there is a chance that scientists may be able to rescue dead heart muscle and improve cardiac function.
In a study, researchers blocked the coronary arteries of experimental animals to cause myocardial infarction. Four weeks later, they injected either bone marrow-derived stem cells or adipose-tissue-derived stem cells into the heart. Impressively, blood flow significantly improved to the heart and heart function. Treated animals had substantially higher left ventricular ejection fraction, essentially reversing heart failure a full month after a heart attack. Shockingly, the researchers found that stem cells appeared to salvage dead heart tissue, meaning that the size of the damaged area was smaller after treatment.
While these incredible results will need to be replicated in humans, this research represents an exciting breakthrough in cardiology and regenerative medicine. The stem cell approach may be able to help patients who have had a heart attack, but could not get medical treatment in time to remove the clot.
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