Diagnosing Coronary Artery Disease
Diagnosis starts with a complete medical history and physical examination. It also may include any of these procedures:
- Electrocardiogram (ECG or EKG) - a test that records the electrical activity of the heart, shows abnormal rhythms (arrhythmias or dysrhythmias), and detects heart muscle damage.
Here’s an example of what an ECG/EKG report looks like:
- Stress Test (usually with ECG; also called treadmill or exercise ECG) - a test that features the patient walking on a treadmill to monitor the heart during exercise, including breathing and blood pressure rates. A stress test may be used not only to detect coronary artery disease, but also to determine safe levels of exercise following a heart attack or heart surgery.
- Cardiac Catheterization - X-rays are taken after a contrast agent is injected into an artery - to locate the narrowing occlusions and other abnormalities of specific arteries.
- Nuclear Scanning – Nuclear medicine techniques, often referred to as myocardial single photon emission computed tomography (SPECT) examine the heart through the intravenous injection of radioactive particles that highlight blood flow to the heart. This process is capable of showing healthy and damaged areas of the heart. Another nuclear technique, positron emission computed tomography (PET) has the ability to determine if heart muscle is viable in the setting of coronary artery blockages. In other words, myocardial PET can help doctors determine if revascularization procedures, such as cardiac bypass surgery or percutaneous coronary interventions performed during cardiac catheterization, such as angioplasty and stent placement, will benefit patients.
Cardiac CT Scan (“CAT” scan) Angiography – Coronary computed tomographic angiography, or CCTA, is a relatively new procedure scan that allows physicians to see important blood vessels that feed the heart muscle. This procedure uses the intravenous injection of contrast, or x-ray dye, during a CT scan to visualize blood flow in the coronary arteries, combined with new, technically advanced computer software to manipulate the data into 3 dimensional (3D) images. CCTA is a non-invasive way to determine if coronary artery atherosclerosis is present. This information can help your doctor determine your risk for a heart attack.
- Cardiac MRI – Magnetic resonance imaging, or MRI, has the ability to obtain exquisite images of the heart and vascular system without the need for ionizing radiation. Many other procedures that are used to evaluate the cardiovascular system, such as SPECT, PET, CCTA, and angiography, must use ionizing radiation to obtain images. While these procedures deliver relatively small doses of radiation and their benefits typically far outweigh any theoretical risks associated with radiation, all ionizing radiation does has the potential to damage tissue and cause harm. Therefore, imaging methods that do not employ ionizing radiation offer a major advantage for the assessment of the cardiovascular system.
Cardiovascular MRI can be used to examine the heart and major blood vessels supplying practically any organ. Cardiac MRI is used to evaluate the function of cardiac valves, to assess for diseases that cause the heart muscle to thicken, stiffen, or the heart chambers to dilate (the so-called cardiomyopathies), to assess for abnormal vascular connections that characterize congenital heart diseases, and to assess for the presence of obstructive coronary artery disease. MRI is also well-suited for assessing the size, shape, and function of the major vessels that exit the heart and supply the lungs and body with blood, and for assessing the exterior lining of the heart- the pericardium. Much like PET scanning, cardiac MR may be used to assess if a patient’s heart will improve function following cardiac bypass surgery or percutaneous interventions using cardiac catheterization, such as angioplasty or stent placement. MRIs also are used to plan a patient's treatment and to monitor progress. MRI has a number of other applications of benefit to patients with cardiovascular diseases.
- Echocardiography – An echocardiogram is a sonogram of the heart. Also known as a cardiac ultrasound, it uses standard ultrasound techniques to image two-dimensional slices of the heart. The latest ultrasound systems now employ 3D real-time imaging. In addition to creating two-dimensional pictures of the cardiovascular system, an echocardiogram can also assess the velocity of blood and cardiac tissue at any arbitrary point. An echocardiogram helps detect abnormal communications between the left and right side of the heart, the leaking of blood through the valves and calculation of the cardiac output.