Cardiac diagnostic testing

MRI (magnetic resonance imaging) uses radiofrequency waves and a strong magnetic field to obtain images of internal organs and tissues. Cardiac MRI gives the physician the ability to clearly see the function and structures of the heart such as the valves and blood vessels. It is also useful in determining the extent of heart damage caused by progressive types of heart disease or a heart attack. Cardiac MRI is being used to diagnose heart diseases earlier, determine treatment and in assessing recovery progress after treatment.

Commonly called a "Heart Scan," a Cardiac Calcium Score is a non-invasive way using x-ray technology with a CT scanner to determine the amount of calcified plaque in the arteries of the heart. Calcium build up is a sign of coronary artery disease (CAD). This can be present and identified even before symptoms are present. The goal of calcium scoring is to screen for coronary artery disease (CAD). Calcium scoring does not image or predict specific narrowing in the arteries of the heart. You do not need a referral for this exam.

This is a non-invasive way to look at the blood flow and specific arteries of the heart. Using x-ray technology from a CT scanner, high speed multiple slice pictures of the heart are taken with the help of intravenous contrast dye. This makes it possible to see the coronary arteries and the degree of plaque build up or narrowing in the arteries. The images are three dimensional and guide doctors as to whether further procedures such as coronary angioplasty, stent placement or coronary bypass surgery might help the patient.

If you have a physical problem that prevents you from walking on a treadmill, your physician may order a stress echocardiogram using a medication called dobutamine. Dobutamine will cause your heart rate to slowly increase and your heart to pump harder. This is similar to the way your heart responds to exercise. The dobutamine will be given through an intravenous (IV) line. The medication will be started at a slow dose. You will be monitored throughout the test. The effects of the dobutamine wear off quickly after the test is done. The test takes 60 - 90 minutes.

Adult and pediatric echocardiogram (Echo)

An echocardiogram (echo) is an ultrasound study of your heart muscle, heart valves and pericardium (sac surrounding the heart) and some of the major blood vessels connected to the heart. The test uses sound waves to see how well your heart is working. 

A wand-like instrument makes the sound waves. As the wand is moved over your chest, pictures of the heart appear on a screen and are recorded. The test takes 30-45 minutes.

A bubble study can be used to add information to a regular echocardiogram or to a transesophageal echocardiogram. The most common reason for doing a bubble study is to look at the wall (septum) that divides the heart down the middle. 

A saline (salt water) solution is injected into your vein and then followed by the ultrasound image as it flows through your heart.

Use of a contrast agent can improve the quality of the pictures obtained during a regular echo or a Stress Echo. This may help the physician to better interpret or read your echo images. To give the contrast agent, a small intravenous (IV) catheter is put in a vein. A small amount of the contrast agent is slowly injected. One or more doses may be needed. The IV will be removed when the echo is completed.

An electrocardiogram is a recording of the electrical activity of your heart. Small, sticky patches are placed on your chest, arms and legs. These patches are connected to a machine that records the electrical activity of your heart, then prints this out on paper for your physician to interpret. The test usually takes less than 15 minutes to complete.

This test will monitor the electrical activity of your heart as you exercise by walking on a treadmill. Exercise increases your heart rate and makes your heart work harder to pump blood to your muscles. You will walk on a treadmill, which will increase in speed and tilt upward (like a small hill) every three minutes for about 10 minutes. It is important that you wear comfortable clothes and walking shoes. If you are taking medicines, talk with your doctor about which ones you may take before this test. You will be asked to not eat or drink anything for two hours before the test. This test takes about one hour to complete.

This is also known as a Cardiolite stress test. This test allows your doctor to see if your heart muscle is getting the amount of blood that it needs through your coronary arteries. 

There are two parts to the test, a "stress" portion and a "rest" portion. Images of your heart will be taken with each portion. A small amount of a safe radioactive medicine, needed for the images, will be injected into your arm for both portions of the test. 

For the "stress" portion, you will walk on a treadmill until you reach a heart rate based upon your age. The radioactive medicine will be injected into your IV as you walk on the treadmill. After a short wait, you will be asked to lie on the exam table while a camera takes images of your heart. 

For the "rest" portion, you will receive an injection of the radioactive medicine and have images taken. 

Comparing the "stress" and "rest" images will help your doctor evaluate any areas where blood flow may be decreased to your heart muscle. 

The complete test may take one to two days to complete. You will know when your appointment is scheduled if it will be one or two days. 

If you are taking medicines, talk with your doctor about which ones you may take before each portion of the test.

Your doctor may want to observe your heart rhythm during your normal, everyday activities. For this test you will wear a small, portable EKG machine on a belt or shoulder strap for 24 or 48 hours. You will be asked to keep a diary of your activities and any unusual feelings that you have such as a fast heart rate, shortness of breath, chest pressure or chest pain.

This test will help your doctor see how well your heart is pumping. A very low dose of radioactive medicine is injected into your IV. Using a computer and a sensitive radiation detector, the radiation within your heart is measured and displayed on a video monitor. 

Before and after the test, you may eat and drink as usual and take your medicines.

If you cannot walk on a treadmill or cannot walk long enough, your doctor may order a stress test done with a special medicine. There are two portions to this test:

• the "stress" portion when the special medicine is infused, and
• the "rest" portion.

During each portion, images using the radioactive medicine (Cardiolite) and a camera will be obtained.

If you cannot walk on the treadmill or can walk for only a very short time, your doctor may have your test done using a medicine (Adenosine) that will increase the amount of blood supply to your heart.

If you cannot walk on the treadmill and also have lung disease, such as asthma or emphysema, your doctor may have your test done with Dobutamine, a medicine that will cause your heart rate to slowly increase and your heart to pump harder.

Each of these medicines is given through an intravenous (IV) line. The radioactive imaging medicine will be injected after the infusion of these medicines. After a short wait, you will lie on the exam table while a camera takes pictures of your heart.

Comparing the "stress" and "rest" images will help your doctor evaluate any areas where blood flow may be decreased to your heart muscle.

The complete test may take one to two days to complete. You will know when your appointment is scheduled if it will be one or two days.

If you are taking medicines, talk with your doctor about which ones you may take before each portion of the test.

A stress echocardiogram (echo) measures how well your heart responds to exercise. It uses ultrasound with a regular stress test to record images of your heart before and after exercise. The test takes 60 minutes.

A transesophageal echocardiogram (TEE) obtains images of your heart from a small ultrasound probe (about the size of a normal piece of food) that is placed in your esophagus or swallowing tube. The probe is at the end of a small flexible tube you swallow. The TEE gives excellent pictures of the heart because the heart lies in front of the esophagus. 

Do not eat or drink anything for six hours before the test. It is important that you ask your doctor for instructions about taking your medicines. 

You will be given medicine to help numb the back of your throat. This will make swallowing the tube easier. 

You will also be given sedating medicine through an intravenous (IV) line that will help you relax and decrease your gag reflex. 

This test requires 1-1/2 to two hours to complete. 

You will need a responsible adult who can drive you home and stay with you for 12 hours after the test.