<P> Recently, the intentional destruction of myocardium by alcohol septal ablation has led to the identification of additional potential markers . </P> <P> Types of cardiac markers include the following: </P> <Table> <Tr> <Th> Test </Th> <Th> Sensitivity and specificity </Th> <Th> Approximate peak </Th> <Th> Description </Th> </Tr> <Tr> <Td> Troponin test </Td> <Td> The most sensitive and specific test for myocardial damage . Because it has increased specificity compared with CK - MB, troponin is a superior marker for myocardial injury . </Td> <Td> 12 hours </Td> <Td> Troponin is released during MI from the cytosolic pool of the myocytes . Its subsequent release is prolonged with degradation of actin and myosin filaments . Isoforms of the protein, T and I, are specific to myocardium . Differential diagnosis of troponin elevation includes acute infarction, severe pulmonary embolism causing acute right heart overload, heart failure, myocarditis . Troponins can also calculate infarct size but the peak must be measured in the 3rd day . After myocyte injury, troponin is released in 2--4 hours and persists for up to 7 days . </Td> </Tr> <Tr> <Td> Creatine Kinase (CK - MB) test </Td> <Td> It is relatively specific when skeletal muscle damage is not present . </Td> <Td> 10--24 hours </Td> <Td> The CK - MB isoform of creatine kinase is expressed in heart muscle . It resides in the cytosol and facilitates movement of high energy phosphates into and out of mitochondria . Since it has a short duration, it cannot be used for late diagnosis of acute MI but can be used to suggest infarct extension if levels rise again . This is usually back to normal within 2--3 days . </Td> </Tr> <Tr> <Td> Lactate dehydrogenase (LDH) </Td> <Td> LDH is not as specific as troponin . </Td> <Td> 72 hours </Td> <Td> Lactate dehydrogenase catalyses the conversion of pyruvate to lactate . LDH - 1 isozyme is normally found in the heart muscle and LDH - 2 is found predominantly in blood serum . A high LDH - 1 level to LDH - 2 suggest MI . LDH levels are also high in tissue breakdown or hemolysis . It can mean cancer, meningitis, encephalitis, or HIV . This is usually back to normal 10--14 days . </Td> </Tr> <Tr> <Td> Aspartate transaminase (AST) </Td> <Td> </Td> <Td> </Td> <Td> This was the first used . It is not specific for heart damage, and it is also one of the liver function tests . </Td> </Tr> <Tr> <Td> Myoglobin (Mb) </Td> <Td> low specificity for myocardial infarction </Td> <Td> 2 hours </Td> <Td> Myoglobin is used less than the other markers . Myoglobin is the primary oxygen - carrying pigment of muscle tissue . It is high when muscle tissue is damaged but it lacks specificity . It has the advantage of responding very rapidly, rising and falling earlier than CK - MB or troponin . It also has been used in assessing reperfusion after thrombolysis . </Td> </Tr> <Tr> <Td> Ischemia - modified albumin (IMA) </Td> <Td> low specificity </Td> <Td> </Td> <Td> IMA can be detected via the albumin cobalt binding (ACB) test, a limited available FDA approved assay . Myocardial ischemia alters the N - terminus of albumin reducing the ability of cobalt to bind to albumin . IMA measures ischemia in the blood vessels and thus returns results in minutes rather than traditional markers of necrosis that take hours . ACB test has low specificity therefore generating high number of false positives and must be used in conjunction with typical acute approaches such as ECG and physical exam . Additional studies are required . </Td> </Tr> <Tr> <Td> Pro-brain natriuretic peptide </Td> <Td> </Td> <Td> </Td> <Td> This is increased in patients with heart failure . It has been approved as a marker for acute congestive heart failure . Pt with <80 have a much higher rate of symptom - free survival within a year . Generally, pt with CHF will have> 100 . </Td> </Tr> <Tr> <Td> Glycogen phosphorylase isoenzyme BB </Td> <Td> 0.854 and 0.767 </Td> <Td> 7 hours </Td> <Td> <P> Glycogen phosphorylase isoenzyme BB (abbreviation: GPBB) is one of the three isoforms of glycogen phosphorylase . This isoform of the enzyme exists in cardiac (heart) and brain tissue . Because of the blood--brain barrier, GP - BB can be seen as being specific to heart muscle . GP - BB is one of the "new cardiac markers" which are considered to improve early diagnosis in acute coronary syndrome . During the process of ischemia, GP - BB is converted into a soluble form and is released into the blood . A rapid rise in blood levels can be seen in myocardial infarction and unstable angina . GP - BB is elevated 1--3 hours after process of ischemia . </P> </Td> </Tr> </Table> <Tr> <Th> Test </Th> <Th> Sensitivity and specificity </Th> <Th> Approximate peak </Th> <Th> Description </Th> </Tr>

What are the different cardiac biomarkers in heart disease