Our diagnostic laboratories are accredited by Intersocietal Commission for the Accreditation of Echocardiography Laboratories (ICAEL), Intersocietal Commission for the Accreditation of Nuclear Medicine Laboratories (ICANL), and Intersocietal Commission for the Accreditation of Vascular Laboratories (ICAVL).
Your cardiologist or primary care physician may request special testing to help understand your heart function and guide treatment. Conducted by experienced technologists, the Lown Group performs the following tests in our fully accredited labs. We will try to schedule your tests and office visits as conveniently as possible, but due to insurance restrictions, two separate visits may be required.
Types of Cardiac Tests We Perform
Click on a test for more information, including special instructions on how to prepare for the test. If you have any questions about a cardiac test, please contact us.
Exercise Tolerance Test
Also called a Stress Test
Stress tests are used to check for abnormal blood flow to the heart due to blocked heart arteries, and to check the heart’s response to exercise. The most common type of stress test involves walking on a treadmill to increase heart rate and blood pressure. However, if you are not able to walk on a treadmill, a “chemical stress test” can be used instead (see “Pharmacologic Myocardial Perfusion Tests” below). Stress tests provide information that may not be apparent on a resting electrocardiogram. Results of a stress test may help explain symptoms that you have reported to your physician.
How to Prepare for the Test
The test takes approximately one hour from start to finish, including preparation time. Wear (or bring) comfortable clothes and walking shoes. Eat a light meal before the test (do not fast!) and take your usual medications unless otherwise directed by your physician. Be sure to drink sufficient water before the test so that you will be well hydrated. A shower and towels are available if you would like to shower afterwards.
The stress echo combines the exercise tolerance test with an ultrasound of the heart, performed before and after exercise. This test looks at the squeezing function of the heart before and after exercise, which is an indication of blood flow. Normally, the heart function becomes stronger after exercise, however if there are blockages in the heart arteries, the muscle may become weaker.
This test takes approximately one hour from start to finish, including preparation time. Wear (or bring) comfortable clothes and walking shoes. Eat a light meal before the test (do not fast!) and take your usual medications unless otherwise directed by your physician. Be sure to drink sufficient water before the test so that you will be well hydrated. A shower and towels are available if you would like to shower afterwards.
Exercise Myocardial Perfusion Test
Also called MIBI or Nuclear Stress Test
The nuclear stress test is similar to the exercise stress test described above, with the addition of a radioactive “tracer”.
For the test, a small intravenous tube (IV) is inserted into a vein. You then receive an injection of a tracer that travels in the blood and is taken up by the heart muscle. Images of the heart muscle are taken 45 minutes later, to assess blood flow to the heart muscle at rest. In order to obtain the images, you will lie under a gamma camera for 20 minutes. These images are repeated after exercising on a treadmill, to increase your heart rate and blood pressure. Your cardiologist will compare the “before” and “after” images to assess for areas of prior damage or decreased blood flow (“ischemia”).
The test is typically performed over a 3-hour period. Occasionally, the test may require two days (visits). The test involves exposure to radiation from the tracer (Technicium-99), comparable to that from an abdominal CT scan. This amount of radiation exposure is considered both reasonably safe and within acceptable limits.
Wear (or bring) comfortable clothes and walking shoes. Eat a light meal about three hours before the test (do not fast!) and take your usual medications unless otherwise directed by your physician. Be sure to drink sufficient water before the test so that you will be well hydrated. A shower and towels are available if you would like to shower afterwards.
Women who may be pregnant should inform the technologist prior to the start of the test.
Pharmacologic Myocardial Perfusion Test
Also called a Regadenoson Nuclear Stress Test
If you are not able to walk on the treadmill, then an intravenous medication will be given instead, to simulate the stress of exercise while you lie flat on a stretcher. The most common medication we use is called “Regadenoson” (or Lexiscan), and it takes about 30 seconds to administer. Some people experience minor side effects including flushing, chest tightness, and headache. These symptoms usually subside within a few minutes. Following the medication, you will lie flat on a stretcher while the nuclear camera acquires images of blood flow in your heart. As with the exercise nuclear stress test, there are two sets of images taken, to compare blood flow before and after the medication.
The test takes about three hours from start to finish. Wear (or bring) comfortable clothes. Eat a light meal about three hours before the test (do not fast!) and take your usual medications unless otherwise directed by your physician. Be sure to drink sufficient water before the test so that you will be well hydrated.
Please note that foods, beverages, and medicines that contain caffeine will interfere with the action of regadenoson, and these must be avoided for at least 12 hours prior to the test. We may need to reschedule your test if there is caffeine in your system.
Please follow these important instructions to prepare for your test:
48 hours prior to your test do not take any of the following medications:
- Any Ephedrine-containing medications
- Any Theophylline-containing medications
24 hours before your test do not take any of the following medications:
- Darvon Compount
12 hours before your test do not eat or drink anything containing caffeine (even decaf). Examples of caffeine-containing products include:
- Coffee (regular and even decaffeinated)
- Many soft drinks
Women who may be pregnant should inform the technologist prior to the start of the test.
Also called a Echocardiogram
The “echo” is an imaging technique that bounces sound waves through the chest to provide a two-dimensional image of the heart muscle, valves, and other cardiovascular structures. This test also provides important information about the pressure inside the heart and lungs. Heart muscle function is evaluated periodically to monitor changes over the years and to guide medical therapy. In patients who have sustained a heart attack, an echo helps assess how the heart is healing. This test usually takes 45 to 60 minutes.
No special dress or preparation is required, although women may wish to wear clothing with separate tops and bottoms, as you will be asked to undress from the waist up. Take your usual medications, and eat and drink normally prior to the test.
This test uses ultrasound to evaluate blood flow in the neck arteries (carotid arteries), and/or in the veins and arteries of the arms and legs. Vascular testing may also be used to evaluate the abdominal aorta. It can detect narrowing of arteries, which may reduce the blood flow through these vessels, or atherosclerosis (“hardening of the arteries”). Vascular testing is performed in our office by Registered Vascular Technologists using state-of-the-art high frequency ultrasound equipment. Depending on the type of study requested the test might take from 45 to 90 minutes. You will receive preparation instructions for this test when it is scheduled.
Holter and Event Monitors
These are small monitors that record your heart rhythm while you are sleeping, exercising at home, and under the daily stresses of life.
A Holter monitor (also called an ambulatory electrocardiography device) is a small device that continuously records your heart rhythm during usual daily activity. These monitors are generally worn for 24 to 48 hours. Your only limitation during this time is that it cannot get wet (i.e. you cannot take a shower or go swimming when wearing the monitor).
An event monitor is a credit card-sized device that you hold against your chest when you want to record a symptom or heartbeat. You will be given a diary in which to record your activities and symptoms, which will then be correlated to the electrocardiogram recording provided by the monitor. It will take about ten minutes in our office for you to be instructed on how to wear and use the monitor. Unlike the Holter monitor, these are not worn continuously on your body. Typically you will carry it with you for 30 days and use it as needed when you have symptoms. Therefore, you can shower and swim as you normally would.
Defibrillator and Pacemaker Evaluations
Many of our patients have implanted pacemakers, defibrillators, or automatic internal cardiac defibrillators (ICDs). The Lown Cardiovascular Group provides full evaluations and monitoring for these devices, including telephonic surveillance.