Diagnostic tests are used to determine if a person has cardiovascular disease. The tests you'll need depend on what condition your doctor thinks you have. Billings Clinic's team of cardiology specialists provide immediate access to excellence in cardiac care.
Before doing any tests, your doctor will likely perform a physical exam before doing any tests. Tests to diagnose heart disease include nuclear stress tests and electrophysiology services.
Cardiac Computed Tomography (CT)
A computed tomography (CT scan) is an X-ray procedure that combines many X-ray images with the aid of a computer to generate cross-sectional views and three-dimensional images of the internal organs and structures of the body.
The cardiac CT scan helps your physician identify soft plaque (blockages) and calcium in the arteries, and look at the structure, shape and size of the heart. In addition, it also views portions of the lungs.
The first image determines a Calcium Score. As we age, arteries develop plaque buildup on the inside. This is called atherosclerosis or "hardening of the arteries." High calcium scores are associated with an increased risk of heart attack. This score can guide the physician in lowering the patient's risk.
This process is completed by a board certified radiologist and/or cardiologist.
Cardiac Catheterization (Coronary Angiogram)
Your doctor may be talking to you about having a cardiac catheterization because you have signs or symptoms of heart trouble. Cardiac catheterization (also called cardiac cath or coronary angiogram) is an invasive imaging procedure that allows your doctor to evaluate your heart function. This procedure is done in the Billings Clinic Cath Lab and is used to:
- Evaluate or confirm the presence of coronary artery disease, valve disease or disease of the aorta
- Evaluate heart muscle function
- Determine the need for further treatment, such as interventional procedure, coronary artery bypass graft or coronary artery bypass (CAB) surgery
During cardiac catheterization, a long narrow tub called a catheter is inserted through a plastic introducer sheath, which is a short and hollow tube inserted into a blood vessel in your leg or arm. The catheter is guided through the blood vessel to the coronary arteries with the aid of a special X-ray machine. With an injected contrast material, the doctor can see movement in the vessels, heart chambers and valves.
Cardiac MRI is a specialized test that provides detailed information to your physicians about the structure and function of your heart muscle. The new technology is commonly being used to supply detailed information about scarring and inflammation of the heart muscle from old or recent heart attack.
A cardiac MRI yields useful information to your physician about what areas of your heart muscle are still alive to better guide revascularlization procedures, like coronary stenting or bypass surgery.
This technology also evaluates other conditions, including:
- Hypertrophic cardiomyopathy (HCM) - A disease in which the heart muscle becomes abnormally thick
- Sarcoidosis - The growth of tiny collections of inflammatory cells in different parts of your body
- Amyloidosis - A disease that occurs when substances called amyloid proteins build up in your organs
- Myocarditis - An inflammation of the myocardium, the middle layer of the heart wall
Cardiac MRIs also evaluate a mass or tumor in the heart.
At Billings Clinic, we use the cardiac MRI to guide catheter-based therapies for arrhythmias, such as atrial fibrillation. Because this is a versatile tool for evaluating structure and blood flow in the chambers of the heart, it is also used for patients with congenital heart diseases.
The average cardiac MRI study takes only one hour. Depending on the indication or information requested by your physician, IV gadolinium contrast may be administered during the test.
Ultrasound is a widely used diagnostic procedure for heart patients. It provides a non-invasive and virtually painless means of observing soft tissue anatomy on an outpatient basis.
There are three kinds of ultrasounds offered at Billings Clinic Cardiac Center:
Echocardiogram - This use a probe that is gently moved across the chest by a trained technologist. This probe emits sound waves that are converted into moving images of the heart and can be recorded digitally. This tells your doctor how the heart is functioning at rest and provides information on the structure, size and how well your heart is pumping.
Exercise echocardiogram - This test, also known as a stress echo, combines an ultrasound study of the heart with an exercise test. The test allows the doctor to learn how the heart functions when it has to work harder. This test is useful in diagnosing heart problems, such as coronary blockages.
Transesophageal echocardiography (TEE) - This ultrasound uses sound waves that are bounced off the heart and reflected back and converted to images on the screen. A trained cardiologist will pass a flexible tube through the mouth and into the esophagus to obtain more information about your heart. This gives clearer pictures of the values, structure and size of the heart.
Exercise stress test, gathers information about how your heart works during physical activity. Because exercise makes your heart pump harder and faster than usual, an exercise stress test can reveal problems within your heart that might not be noticeable otherwise.
An exercise stress test involves walking on a treadmill while your heart rhythm, blood pressure are being monitored. Your doctor may recommend an exercise stress test if he or she suspects you have coronary artery disease or an irregular heart rhythm (arrhythmia). The test may also be used to guide your treatment if you've already been diagnosed with a heart condition.
How is a Regular Treadmill Stress Test Performed? The patient is brought to the exercise laboratory where the heart rate and blood pressure are recorded at rest. Sticky electrodes are attached to the chest and shoulders connected to the EKG portion of the Stress test machine.
The treadmill is then started at a relatively slow "warm-up" speed. The treadmill speed and it's slope or inclination are increased every three minutes according to a pre-programmed protocol (Bruce is the commonest protocol in the USA, but several other protocols are perfectly acceptable).
The patient's blood pressure is usually recorded during the second minute of each Stage. However, it may be recorded more frequently if the readings are too high or too low. The physician pays particular attention to the heart rate, blood pressure, changes in the EKG pattern, irregular heart rhythm, and the patient's appearance and symptoms. The treadmill is stopped when the patient achieves a target heart rate (this is 85% of the maximal heart rate predicted for the patient's age). However, if the patient is doing extremely well at peak exercise, the treadmill test may be continued further.
There are several ways to monitor your heart and learn about how electrical impulses go through it.
Electrocardiogram (EKG) -- To perform an electrocardiogram (EKG), we place electrodes on your body. Electrical impulses are conducted to external surface and then a tracing is made. This testing lasts a little less than a minute. Interpretation of this information allows diagnosis of a wide range of heart conditions. These conditions can vary from minor to life threatening.
Holter monitoring -- Holter monitoring is a continuous recording of your EKG that lasts for 24 hours. You will be asked to keep a journal and push the button on the monitor if you experience any palpitations, dizziness, or chest pain. This monitoring is useful in diagnosing any abnormal heart rhythm.
Event Recording -- Event monitors are slightly smaller than Holter monitors. They can be worn for weeks or until symptoms occur. When you have symptoms, you simply push a button on your monitor to start recording. This monitor can record 3 events before you need to call us and download the information for your health care provider to review.
Nuclear Stress Test
A Nuclear Stress Test shows how well blood flows through your heart and arteries while you are resting and during physical exertion. In this test, a small amount of a radioactive substance is injected into your body.
This substance allows images of the heart to be recorded so that your doctor can see:
- How well the heart is pumping blood
- If a part of the heart has been damaged
- If any of the arteries that feed the heart are blocked
Preparing for your test
It is important that you follow very specific instructions before your nuclear stress test takes place to ensure accurate measurements.
- Do not eat or drink any caffeinated products (including cola or soda, tea, coffee or chocolate) for 24 hours before your test
- Report all of the medications you take. Ask if you should stop taking any medications before your test. Some medications, such as blood pressure medicine, nitroglycerin and beta-blockers, can interfere with the test
- Do not take over-the-counter medications that contain caffeine before your test, including diet pills, Anacin®, Excedrin® or Vanquish®. For questions about caffeinated medicine, contact your doctor
- If you are pregnant or nursing, tell the staff before your visit
For those with diabetes, please be aware:
- If you take insulin, ask your doctor what amount you should take the day of your test. If you take diabetes pills, do not take your medication until after your test.
During the test
A nuclear stress test usually takes 2-4 hours. Two sets of images will be taken: One while you are resting and one after you have exercised. This test is usually done in a special laboratory.
Images taken while resting
- Your will be asked to lie down on an exam table and an IV will be placed into your vein in your arm or hand.
- A radioactive substance is injected through the IV. You will need to lie still with your arms above your head for 15-20 minutes to allow the substance to circulate
- You will be taken to another area of the lab where a special camera will read traces of the substance and sends images to a monitor. Your doctor will be able to see the blood flowing through your heart and arteries
Before your exercise test
- Small discs called electrodes will be placed on your chest. These are connected to an EKG machine, which will chart your heart's electrical activity
- You will walk on a treadmill for a few minutes. Your rate of exercise will slowly be increased
- You will be asked how you are feeling. Be sure to report any symptoms including pain, discomfort in your chest, arm or jaw, shortness of breath and dizziness
If you are unable to exercise, you will be given medications that cause the heart and blood vessels to react as they would during exercise. The medications may cause sensations such as tightness in the throat and chest, along with a hot, flustered feeling. This is normal and will go away after 4 or 5 minutes.
After your exercise test
- After several minutes, you will be given another injection of the radioactive substance
- You will be asked to lie down for another scan of your heart. Again, lie still with your arms above your head for 15-20 minutes. Images taken at this time shows how the blood is moving through the arteries and heart during physical exertion
- A cardiologist will compare the images that were taken before and after exercise
After your test
You will be told when you can eat and drink, and when you can take medications, after your test is complete. The radioactive substance used in this test is safe and will not harm your body. The substance will leave your body within a few hours.
Your doctor will discuss your test results with you after he or she has the chance to review all the information gathered.