Cardiac marker

Biomarkers used to evaluate heart function

Cardiac markers are biomarkers measured to evaluate heart function. They are often used in the diagnosis and management of acute coronary syndromes (ACS) and other conditions associated with myocardial injury.

Types of Cardiac Markers

Acute myocardial infarction blood tests

Cardiac markers are substances that are released into the blood when the heart is damaged or stressed. The most commonly used cardiac markers include:

Troponins

Troponins are proteins found in cardiac muscle that regulate muscle contraction. They are considered the most specific and sensitive markers for myocardial injury. Troponin levels rise within a few hours of heart damage and can remain elevated for up to two weeks.

Creatine Kinase-MB (CK-MB)

Creatine kinase is an enzyme found in the heart, brain, and skeletal muscle. The MB isoenzyme is more specific to the heart. CK-MB levels rise within 3-6 hours of myocardial infarction and return to normal within 48-72 hours.

Myoglobin

Myoglobin is a small protein that carries oxygen in muscle cells. It is one of the earliest markers to rise after myocardial injury, but it is not specific to the heart, as it is also found in skeletal muscle.

B-type Natriuretic Peptide (BNP)

B-type natriuretic peptide is a hormone produced by the heart in response to ventricular volume expansion and pressure overload. It is used primarily in the diagnosis and management of heart failure.

C-reactive Protein (CRP)

C-reactive protein is a marker of inflammation that can be elevated in various conditions, including heart disease. High-sensitivity CRP (hs-CRP) is used to assess the risk of cardiovascular events.

Clinical Use

Reference ranges for blood tests

Cardiac markers are used in various clinical scenarios, including:

• Diagnosis of Myocardial Infarction: Elevated levels of troponins are the gold standard for diagnosing myocardial infarction.
• Risk Stratification: Cardiac markers help in assessing the risk of future cardiovascular events.
• Monitoring Therapy: They are used to monitor the effectiveness of treatment in patients with heart disease.

Limitations

While cardiac markers are invaluable in diagnosing and managing heart conditions, they have limitations. For instance, elevated troponin levels can occur in conditions other than myocardial infarction, such as myocarditis, pulmonary embolism, and chronic kidney disease.

Future Directions

Research is ongoing to identify new cardiac markers that can provide more specific and sensitive information about heart health. Advances in genomics and proteomics may lead to the discovery of novel biomarkers.

Related Pages

• Acute coronary syndrome
• Myocardial infarction
• Heart failure
• Biomarker

Comparison of cardiac markers

Comparison of cardiac markers 2