Introduction:
The heart releases cardiac enzymes (cardiac biomarkers) when heart damage or stress occurs due to a low oxygen level. Troponin and creatinine phosphokinase (CPK) levels are elevated after a heart attack. Increased heart enzyme levels can also signal acute coronary syndrome or ischemia. Doctors advise cardiac enzyme marker tests (blood tests) to measure cardiac enzymes.
What Are Cardiac Enzymes?
Enzymes are proteins that help the body to manage specific functions like metabolism, chemical processes, etc. Many enzymes are used for specialized functions, like blood clotting, brain, spine, nerve functioning, breathing, digestion, musculoskeletal movements, and excreting waste from the body through urination. The heart experiences damage or stress due to a lack of oxygen. In that condition, it releases substances called cardiac enzymes into the bloodstream. Various cardiac enzymes are used to evaluate the damage caused to the heart.
Tests for cardiac troponins are done mostly by doctors. The proteins troponin T and troponin I are the main biomarkers in a test for cardiac enzymes. Skeletal muscle too produces troponins, but there are various subtypes of its present. This indicates that if troponins I and T are seen in a cardiac enzyme test, they will likely highlight cardiac issues. This biomarker helps doctors to determine when the heart has been under stress. It can also show whether the heart muscles are not getting sufficient oxygen.
What Is a Cardiac Enzyme Test?
An enzyme marker test is a type of blood test to measure specific biological markers (biomarkers) in the blood. High cardiac enzyme levels can indicate a heart attack or any other heart defect. Cardiac enzymes are also known as cardiac biomarkers. The doctors advise this test in the following conditions:
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Chest pain or pressure.
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Dizziness.
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Feeling too weak or tired.
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Sweating and cool, clammy skin.
Why Are Cardiac Enzyme Tests Required?
In case a person is suspected of having a heart attack or might have had it recently or have other damage to the heart due to inflammation (myocarditis), a cardiac enzyme test is performed. This test measures the level of a few proteins present in the bloodstream. Such a test helps the doctor to confirm the diagnosis and start the treatment. After a heart attack, levels of troponins T and I may start to increase within around four hours. They remain high for many days, so they help indicate a heart attack.
How Is the Cardiac Enzyme Test Performed?
It is similar to other blood tests. A thin needle takes a small amount of blood, most likely from the arm near the elbow. A pinch or sting is felt when the needle is pushed slightly in, which is typical. It only takes around a minute or two to be done. The results are obtained soon (within an hour or two) since these tests are frequently urgent. This test assesses the biomarker levels to confirm whether a person had a heart attack and assess the extent of damage caused to the heart muscles. The doctor might do the same enzyme tests over time to see how the level of enzyme changes.
What Do the Results Mean?
The results of the cardiac enzymes can indicate whether a person had a heart attack or incurred any other type of heart problem. For instance, most healthy young people do not have increased troponin T circulating in their bloodstream. The more damage is caused to the heart muscles, the higher the level of troponin T circulating in the blood. Doctors these days use high-sensitivity troponin to check for damage with high sensitivity. The unit for measuring cardiac troponin T is in nanograms per milliliter (ng/mL). If the troponin T level is higher than the 99th percentile for this test, the doctor will likely diagnose it as a heart attack. Levels that start high and fall indicates a recent injury to the heart. It could have been a mild heart attack or heart damage caused to the muscles of the heart, of which a person might remain unaware.
What Are the Factors That Determine the Level of Enzymes?
Cardiac enzyme levels can increase for reasons other than a heart attack also. For example, sepsis (a type of blood infection) can result in elevated troponin levels. The same is correct for atrial fibrillation, a common heart rhythm problem. Other factors that can affect the test results include:
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A blood clot in the lungs.
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Acute or chronic heart failure.
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Amyloidosis.
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Brain injury.
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Cardiac contusion due to a chest wall injury.
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Cardioversion to treat atrial fibrillation or atrial flutter.
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Chemotherapy treatments.
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Coronary angioplasty.
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Defibrillation for ventricular fibrillation or tachycardia.
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End-stage kidney disease.
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Myocarditis or myopericarditis.
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Open heart surgery.
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Other heart conditions, such as cardiomyopathy.
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Radiofrequency catheter ablation of arrhythmia.
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Strenuous exercise.
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Valvular heart disease.
Since other factors can also trigger a spike in cardiac enzyme levels, the doctor will not rely solely on the enzyme levels to diagnose a heart attack. They will also use an electrocardiogram and symptoms to confirm a diagnosis.
What Are the Side Effects of Cardiac Enzyme Test?
Possible side effects and complications of cardiac enzyme test:
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A cardiac enzyme test is relatively simple and painless.
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Some minor bruising or temporary soreness is felt at the site where the needle is inserted (to draw blood).
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If the person is allergic to latex, they must inform the doctor. This can help avoid complications. The test is safe and mostly risk-free in most cases.
Conclusion:
Enzymes are the protein substances that help promote various body processes such as metabolism, chemical processes, etc. Few such enzymes are used in the detection of any cardiac abnormality in the heart, such as heart attack or severe cases of angina. There are several kinds of cardiac enzymes, the most known of which is troponin, a protein released from the heart's cells when they are damaged. Two types of troponin (T and I) are tested, and both are equally sensitive. The level of these enzymes is whether a person might have a heart attack or have had about any other cardiac issues.
