Diagnosis Of Heart Attack
If you experience pain in the chest or discomfort, then your doctor might advise some blood and imaging tests to determine the underlying cause.
A. Lab tests
Some of the commonly advised lab tests include:
1. Lipid Profile Test
This is a group of blood tests that detects the levels of different types of lipids in the blood. Lipids are fatty substances that play an important role in a number of body functions. Apart from being structural components of the cells, lipids also act as a source and mode of storage of energy for the body.
It typically measures the levels of total cholesterol, High Density Lipoprotein (HDL) cholesterol, Low Density Lipoprotein (LDL) cholesterol, and triglycerides. Other results that may be reported include Very-Low-Density Lipoprotein (VLDL) cholesterol, non-HDL cholesterol, and total cholesterol to HDL cholesterol ratio.
2. C-reactive protein (CRP) test
C-reactive Protein (CRP) is a protein secreted by the liver in response to inflammation caused by injury, infection, or otherwise. The C-reactive protein (Quantitative) test measures the levels of C-reactive protein in blood to determine the presence of inflammation or infection and to monitor treatment.
3. Cardiac troponins (I and T)
Troponins are proteins which are found in the heart muscles and skeletal muscle fibres. These are known to help regulate muscular contraction. This test helps measure the level of cardiac-specific troponin in the blood thereby helping in the diagnosis of any heart injury or damage.
4. Creatine kinase (CK)
Also known as Total CK, Creatine Phosphokinase, and CPK test, this test is done to detect and monitor damage to muscle. It is also done to diagnose conditions which are associated with muscle damage and to detect any possible case of heart attack.
A more specific test known as Creatine Kinase-MB (CKMB) is also recommended.This test measures the enzyme Creatine Kinase (CK) MB, which is mainly found in cells of heart muscles, in blood. It is also found in skeletal muscles but in a lesser amount.
5. Myoglobin
This assay is useful for assessing muscle damage from any cause. Elevated myoglobin levels are seen in cases of acute muscle injury, resuscitation, myopathies, shock & strenuous body activity.
B. Imaging & other tests
In addition to the blood work, some of the other tests that can help in the diagnosis of myocardial infarction or a blockage in the heart include:
1. Electrocardiogram (EKG / ECG): This resting 12 lead ECG test is the first-line diagnostic tool for the diagnosis of acute coronary syndrome (ACS). It should be obtained within 10 minutes of the patient’s arrival in the emergency department. Acute MI is often associated with dynamic changes in the ECG waveform. Serial ECG monitoring can provide important clues to the diagnosis if the initial EKG is non-diagnostic at initial presentation.
2. Holter monitoring or ambulatory ECG or ambulatory EKG: A holter monitor is a small, wearable device that keeps track of your heart rhythm. This monitoring is used to diagnose intermittent cardiac arrhythmias.
3. Echocardiography: A cardiac echo is used to identify abnormalities in the heart's structure and function.
4. Stress test:This test involves measuring the performance of the heart while undergoing exercise of gradually increasing intensity on a treadmill.
5. Carotid ultrasound: A carotid ultrasound is an important test that can detect narrowing, or stenosis of the carotid arteries. Carotid artery stenosis is a major risk factor for stroke.
6. Tilt table test: The tilt table test (also called a passive head-up tilt test or head upright tilt test) records your blood pressure, heart rhythm and heart rate on a beat-by-beat basis
7. MRI of the heart: A heart MRI (magnetic resonance imaging) uses magnets and radio waves to create an image of your heart and nearby blood vessels.
8. Cardiac CT: The Computed Tomography (CT) Scan of heart is an imaging test which is used to create a detailed three dimensional image of the heart and coronary blood vessels and helps to assess the condition of the blood vessels and understand blood flow through them and help to diagnose various heart diseases.
9. Coronary angiography: A coronary angiogram is a procedure that uses X-ray imaging to check the heart's blood vessels.
10. Cardiac catheterization: Cardiac catheterization (cardiac cath or heart cath) is a procedure to examine the working of the heart. A thin, hollow tube called a catheter is inserted into a large blood vessel that leads to your heart to find out the origin of disease of the heart muscle, valves or coronary (heart) arteries.
11. Radionuclide ventriculography or radionuclide angiography (MUGA Scan): A radionuclide angiogram is a test used to gather images of the heart throughout its pumping cycle it is also referred to as a MUGA scan (multigated acquisition scan) or blood pool scan.
12. Transesophageal echocardiography (TEE): TEE is a test that produces pictures of the heart. TEE uses high-frequency sound waves (ultrasound) to make detailed pictures of your heart and the arteries surrounding it.
C. Nuclear heart scans
Similar to angiography, these scans use a radioactive dye injected into your blood. What sets them apart from an angiogram is that they use computer-enhanced methods like computed tomography (CT) or positron emission tomography (PET) scans.
1. Positron emission tomography (PET) scan: This test uses radioactive dyes to produce pictures of the heart. PET scans differentiate between healthy and damaged heart muscles.
2. Single photon emission computed tomography (SPECT): A SPECT scan uses radioactive tracers that are injected into blood to produce pictures of the heart to check how well blood is flowing to the heart.
3. Myocardial perfusion imaging (MPI) test: This test shows how well blood flows through your heart muscle. It also helps to show areas of the heart muscle that aren’t getting enough blood.