Plasma biochemical markers

Certain proteins that are usually found mainly within the cells of the heart tissue are released into  the bloodA fluid that transports oxygen and other substances through the body, made up of blood cells suspended in a liquid. during a heart attackThe death of a section of heart muscle caused by an interruption in its blood supply. Also called a myocardial infarction.. These proteins therefore act as 'biochemical markersCertain substances found in the blood or other body fluid that indicate a disease when detected.' of disease.

There are several different biochemical markersCertain substances found in the blood or other body fluid that indicate a disease when detected. that are useful in diagnosing a heart attackThe death of a section of heart muscle caused by an interruption in its blood supply. Also called a myocardial infarction.: these include creatine kinaseA type of protein, an enzyme, that helps to break down the substance creatine to become creatinine in the body. Various forms exist in the brain, thyroid, skeletal muscle and heart muscle., creatine kinase-MBA form of creatinine kinase (an enzyme) that is present in heart tissue. Any damage to the heart muscle, for example from a heart attack, can cause a raised level of the substance in the bloodstream., troponin TA type of troponin (proteins found in muscle) specific to heart muscle. and troponin IA type of troponin (proteins found in muscle) specific to heart muscle.. In someone with a suspected heart attackThe death of a section of heart muscle caused by an interruption in its blood supply. Also called a myocardial infarction., these proteins will usually be measured on a daily basis.[1,5]

As well as being found within the heart muscleTissue made up of cells that can contract to bring about movement., creatine kinaseA type of protein, an enzyme, that helps to break down the substance creatine to become creatinine in the body. Various forms exist in the brain, thyroid, skeletal muscle and heart muscle. is also found in the type of muscleTissue made up of cells that can contract to bring about movement. responsible for movement, known as skeletal muscleA type of muscle responsible for movement that a person controls consciously (a voluntary muscle).. This means that levels of creatine kinaseA type of protein, an enzyme, that helps to break down the substance creatine to become creatinine in the body. Various forms exist in the brain, thyroid, skeletal muscle and heart muscle. may sometimes be raised by causes other than a heart attackThe death of a section of heart muscle caused by an interruption in its blood supply. Also called a myocardial infarction. that can injure muscleTissue made up of cells that can contract to bring about movement. tissue, including falls, seizures or prolonged exercise.[3] Plasma biomarkersA substance that can be measured to help healthcare professionals to assess normal processes, disease processes or a person's response to treatment. can even be raised after someone has an injection into muscleTissue made up of cells that can contract to bring about movement. tissue A group of cells with a similar structure and a specialised function.(an intramuscular injection).[4]

Similarly, levels of troponinA group of proteins found in muscle. can also be raised by a number of causes in addition to a heart attackThe death of a section of heart muscle caused by an interruption in its blood supply. Also called a myocardial infarction.. These include heart failureFailure of the heart to pump adequately., kidney failure and toxic effects from various drugs.[2]

Raised levels of plasmaFluid in which the blood cells are suspended. biochemical markersCertain substances found in the blood or other body fluid that indicate a disease when detected. are therefore not totally specific to a heart attackThe death of a section of heart muscle caused by an interruption in its blood supply. Also called a myocardial infarction..

Another problem with measuring plasmaFluid in which the blood cells are suspended. biomarkersA substance that can be measured to help healthcare professionals to assess normal processes, disease processes or a person's response to treatment. is that their levels do not rise immediately after a heart attackThe death of a section of heart muscle caused by an interruption in its blood supply. Also called a myocardial infarction., but increase slowly over a period of hours.[6] Because of this, immediate treatment decisions are often made on the basis of the person's ECGAbbreviation for electrocardiogram, a tracing of the electrical activity of the heart to help in the diagnosis of heart disease., history and clinical symptoms and signs.

References: 
  1. Boon NA, Colledge NR and Walker BR. Davidson's Principles and Practice of Medicine. Churchill Livingstone Elsevier. 2006; 20th edition.
  2. Universal definition of myocardial infarctionDeath of an area of heart muscle due to poor blood supply.. Thygesen K, Alpert JS, White HD. Circulation 2007;116;2634-53.
  3. Longmore M, Wilkinson I, Török E. Oxford Handbook of Clinical Medicine. 2002; 5th edition.
  4. Improving the early diagnosisThe process of determining which condition a patient may have. of acuteHas a sudden onset. myocardial infarctionDeath of an area of heart muscle due to poor blood supply.. Banerjee A. Postgrad Med J 1996;72:705-8.
  5. Unstable anginaA central chest pain caused by insufficient oxygen supply to the heart. and non-ST-segment myocardial infarctionDeath of an area of heart muscle due to poor blood supply.: An evidence-based approach to management. Kou V and Nassisi D. The Mount Sinai Journal of Medicine 2006;73(1):449-68.
  6. Diagnosis and management of ST elevation myocardial infarctionDeath of an area of heart muscle due to poor blood supply.: a review of the recent literature and practice guidelines. Hahn SA and Chandler C. The Mount Sinai Journal of Medicine 2006;73(1):469-81.