Which cardiac marker is most specific?Asked by: Andres Kuhn
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Troponin (I or T)—this is the most commonly ordered and most specific of the cardiac markers. It is elevated (positive) within a few hours of heart damage and remains elevated for up to two weeks. Rising levels in a series of troponin tests performed over several hours can help diagnose a heart attack.View full answer
In respect to this, Which cardiac marker is the most specific for cardiac damage?
Cardiac troponins T and I are the preferred markers for myocardial injury as they have the highest sensitivities and specificities for the diagnosis of acute myocardial infarction.
Regarding this, What is the most specific cardiac marker of acute MI is suspected?. Cardiac troponins are specific and sensitive biomarkers of cardiac ischemia, and they are the preferred blood test in the evaluation of patients suspected to have acute MI. There are sensitive and highly sensitive assays to detect cardiac troponin levels in the blood.
Hereof, Which cardiac enzyme is most specific?
In most clinical settings, cardiac troponin is the cardiac enzyme of choice, and other enzymes should not be routinely used. There are many reasons for this, but ultimately, troponin has been shown to be more specific and more sensitive to cardiac injury.
Which is the most specific and sensitive cardiac marker for myocardial damage?
It has the highest known sensitivity. It enters into your bloodstream soon after a heart attack. It also stays in your bloodstream days after all other biomarkers go back to normal levels. Two forms of troponin may be measured: troponin T and troponin I.
Cardiac troponin I: the gold standard in acute myocardial infarction diagnosis.
The earliest biomarker to increase is the muscle enzyme, CK or CPK, which is present in the cytosol of the myocytes and predominantly released into the bloodstream from the necrosed myocardium. The CK-MB fraction being more specific to the myocardium quickly replaced the CK and is considered the gold standard.
Overall, troponin I is a better cardiac marker than CK-MB and should become the preferred cardiac enzyme when evaluating patients with suspected myocardial infarction.
Cardiac troponin I appears to be a more specific marker of risk of composite cardiovascular disease and coronary heart disease, whereas cardiac troponin T is more strongly associated with risk of non–cardiovascular disease death.
Levels of troponin can become elevated in the blood within 3 to 6 hours after heart injury and may remain elevated for 10 to 14 days. Increased troponin levels are not be used by themselves to diagnose or rule out a heart attack.
Troponin I is extremely specific for the cardiac muscle and has not been isolated from the skeletal muscle. This absolute specificity makes it an ideal marker of myocardial injury (41). They are released into the circulation 6–8 h after myocardial injury, peak at 12–24 h and remain elevated for 7–10 days (42).
The diagnosis of myocardial infarction requires two out of three components (history, ECG, and enzymes). When damage to the heart occurs, levels of cardiac markers rise over time, which is why blood tests for them are taken over a 24-hour period.
However, CK-MB is not completely cardiac specific, also increasing in skeletal muscle disease or injury, kidney failure, intramuscular injection, strenuous exercise, and after exposure to several toxins and drugs.
Stress-induced cardiomyopathy mimics symptoms of acute myocardial infarction with acute chest pain, electrocardiographic changes and a transient increase in the level of cardiac biomarkers including troponins.
Cardiac markers can be classified into those that signify myocardial necrosis (creatine kinase-MB [CK-MB] fraction, myoglobin and cardiac troponins), those that indicate myocardial ischemia (ischemia modified albumin), those that suggest myocardial stress (natriuretic peptides), and those markers of inflammation and ...
Myoglobin is a heme protein found in skeletal and cardiac muscle that has attracted considerable interest as an early marker of MI.
Troponin elevation is a marker of cardiac injury and high risk, it is also raised in a minority of acute coronary syndrome patients. However, it is important for clinicians to realise that a single rise in troponin levels is of indeterminable significance.
Having a result between 0.04 and 0.39 ng/ml often indicates a problem with the heart. However, a very small number of healthy people have higher than average levels of troponin. So, if the result is in this range, a doctor may check for other symptoms and order further tests before making a diagnosis.
The assay has high precision at low concentrations and can detect cTnI in 96.8% of healthy individuals.
Cardiac troponin levels are normally so low they cannot be detected with most blood tests. Having normal troponin levels 12 hours after chest pain has started means a heart attack is unlikely.
Thus, when the high-sensitivity cardiac troponin T test detects levels above 14 ng/l, heart damage or heart attack is likely.
Cardiac troponins are detected in the serum by the use of monoclonal antibodies to epitopes of cTnI and cTnT. These antibodies are highly specific for cardiac troponin and have negligible crossreactivity with skeletal muscle troponins.
Cardiac biomarkers are substances that are released into the blood when the heart is damaged or stressed. Measurements of these biomarkers are used to help diagnose acute coronary syndrome (ACS) and cardiac ischemia, conditions associated with insufficient blood flow to the heart.
Cardiac enzymes ― also known as cardiac biomarkers ― include myoglobin, troponin and creatine kinase. Historically, lactate dehydrogenase, or LDH, was also used but is non-specific.
Palpation should be done using the fingertips and intensity of the pulse graded on a scale of 0 to 4 +:0 indicating no palpable pulse; 1 + indicating a faint, but detectable pulse; 2 + suggesting a slightly more diminished pulse than normal; 3 + is a normal pulse; and 4 + indicating a bounding pulse.