Blood tests for heart disease
What are Blood tests for heart disease?
Heart disease in its many forms can be difficult to detect. Several blood tests have been developed that measure the levels of various substances that can detect either the presence of heart disease or to predict the level of risk in the future.
Why is it conducted?
Different blood tests are conducted to accurately diagnose and monitor various heart diseases as well as to gauge the need for preventive care for high risk population.
Tests conducted for diagnosing heart disease:
- Natriuretic peptides (B type) : The brain natriuretic peptide is a hormone that is generally raised in the blood stream only if there is some degree of heart failure. The higher the levels, the greater the severity of heart failure.
- Creatine kinase (CK): The presence of creatine kinase in the blood indicates some level of muscle damage and may not necessarily indicate damage to heart muscle exclusively.
- Creatine kinase-MB (CKMB): This test is recommended in case of raised CK levels. If the level of CK-MB is more than half of total CK then it is considered to be indicative of heart damage due to any cause.
- Myoglobin: Myoglobin can be found in the blood in the event of damage to both, heart or skeletal muscle.
- Cardiac troponin I or cardiac troponin T: The cardiac troponin test is more sensitive as this is found in the blood only if there has been any damage to heart muscle cells.
- Ischemia modified albumin (IMA): This indicates a reduced blood flow to the heart and increased chances of a heart attack.
Tests conducted to understand risk level:
- C-reactive protein: The presence of this protein indicates inflammation of some kind within the body.
- Fibrinogen: High levels of this protein in the blood can indicate atherosclerosis or a tendency towards blood clots in the arteries.
- Homocysteine: High levels of this substance are said to heighten the risk for heart disorders.
- Cholesterol test: Tests that measure your total cholesterol level, including the ratio of HDL and LDL cholesterol are a definite indicator of the level of risk that you have.
- Lp-PLA2: Raised levels of Lipoprotein-Associated Phospholipase A clearly point towards increased chances of cardiovascular disorders.
Who should go for it?
In the case of suspected heart disease various tests are conducted to ensure accurate diagnosis so that timely and proper treatment can be started.
- Persons who are suffering from chest pain, shortness of breath, excessive sweating along with nausea may be ordered tests to confirm whether it is a heart attack.
- But often the risk of heart disease exists long before any noticeable symptoms appear. An assessment of the risk of developing heart disease in the future helps to begin preventive care and introduce lifestyle changes.
- Persons with a known family history of heart disease are generally advised blood tests for heart disease to lower the possibility of a sudden attack.
These are simple blood tests that do not require any kind of preparation or diet restriction beforehand. Blood will be drawn from either the inside of the elbow or the back of your hand by a technician.
Interpretation of results
- Natriuretic peptides(B type) : Normal ranges are considered to range from 0 to 99 pg/mL.
- Creatine kinase (CK): The normal values lie within 60 to 174 IU/L.
- Creatine kinase-MB (CKMB): Levels of this enzyme will become evident in the blood only after a gap of 6 hours. Normal levels are from 0 to 3 ng/ml.
- Myoglobin: Though it does not denote damage to the heart exclusively, it is useful as it peaks within a couple of hours of damage. Normal ranges for a female are 1-66 ng/ml and for a male 17-106.
- Cardiac troponin I or cardiac troponin T: Normal value is less than 0.02.
- C-reactive protein: It should be less than 1.0 mg/L.
- Fibrinogen: Normal levels fall between 200 and 400 mg/L.
- Homocysteine: It should be between 4.4 and 10.8 µmol/L.
- Cholesterol test: Total cholesterol should be around 200 mg/dL, LDL should be less than 130 mg/dL, HDL 60 mg/dL whereas triglycerides should be below 150 mg/dL.
- Lp-PLA2: Values less than 200ng/mL are considered normal.
- Ischemia modified albumin (IMA): As changes in this can be observed almost immediately, it can be used with reasonable accuracy to diagnose ischemia.
Written by: Nandita tripati
Date last updated: January 10, 2015