Non-invasive procedures do not require surgery or a hospital stay. They are used to determine whether a problem exists and whether additional testing and treatment is necessary. The non-invasive cardiac services at the Memorial Health Heart & Vascular Institute are overseen by a full-time board-certified cardiologist. Our services include EKG testing, Holter monitoring, echocardiography, stress testing, and nuclear studies. All tests must be ordered by a physician.


Echocardiography (also called echo, cardiac ultrasound or ultrasonography, cardiac Doppler, transthoracic echocardiography, or TTE) is a computer procedure that allows physicians to study the way the heart and its valves are functioning. An ultrasound machine creates a moving image of the heart by bouncing soundwaves over it. The process is simple and painless.

There are several diseases of the heart that may be detected by echocardiography, including, but not limited to, the following:

  • Atherosclerosis (also called coronary artery disease) – a gradual clogging of the arteries over many years, caused by fatty materials and other substances in the blood stream.
  • Aneurysm – a dilation of a part of the heart muscle or the aorta that may weaken tissue at the site of the aneurysm. In extreme cases, the aneurysm may rupture, causing a medical emergency.
  • Cardiomyopathy – an enlargement of the heart due to thickening or weakening of the heart muscle.
  • Congenital defects – defects in one or more heart structures that occur before birth, while the fetus is forming.
  • Congestive heart failure – a condition in which the heart muscle becomes so weak that blood cannot be pumped efficiently. This causes a build up in the blood vessels, lungs, feet, ankles, and other parts of the body.
  • Pericarditis – an inflammation or infection of the sac that surrounds the heart.
  • Valve disease – malfunction of one or more of the heart valves that may obstruct blood flow within the heart.

Transesophageal Echocardiography

A transesophageal echocardiogram (TEE) is a special form of echocardiogram that is performed through the esophagus (the tube that runs from the mouth to the stomach). A TEE gives doctors a clearer image of the heart than they can get from a regular ultrasound through the chest wall.

During the procedure, you will receive I.V. medications to numb your throat and sedate you. To perform the test, a flexible tube called a probe is passed through the mouth into the esophagus. An echo apparatus, or transducer, is at the end of the probe. The sound waves from the transducer reflect off of the heart and give information about the valves and other structures inside the heart. The sound waves can even tell doctors how well the heart is pumping. The actual procedure itself takes approximately 25 minutes. The entire process, from pre-testing until the time you recover from the sedation, takes two to three hours.

You should feel very little discomfort. Your throat may be somewhat sore after the procedure. Major complications are rare, but include perforation (piercing) of the esophagus, rhythm disturbances, reaction to sedatives, and bleeding.

To prepare for a TEE, please follow these instructions as well as any other directions your doctor gives you:

  • No food for at least four hours.
  • Arrange for a ride home. Do not plan to drive.
  • Let the doctor know if you have any swallowing problems.
  • Make everyone aware of any allergies you may have.
  • Bring a container for any dentures or oral prosthesis.
  • Write down any questions you may have so that you can ask them before the procedure.

EKG and Holter Monitoring

The electrical activity of the heart is measured by an electrocardiogram (EKG or ECG). By placing electrodes at specific locations on the body (chest, arms, and legs), a graphic representation, or tracing, of the electrical activity can be obtained. Changes in an EKG from the normal tracing can indicate a specific heart condition.

Holter monitoring involves wearing a portable EKG device that records the heart’s electrical activity for a period of 24 to 72 hours.

Both EKG and Holter monitoring are painless procedures.

Nuclear Cardiology/Radioisotope Stress Test

Nuclear cardiology refers to the use of nuclear medicine or radioisotope techniques to study heart problems. A radioisotope stress test is used to determine whether the heart is getting enough blood. During the “stress” portion of the test, you may be asked to exercise on a treadmill or bicycle. In some cases, the stress will be induced with chemicals such as adenosine or Persantine. The chemicals or exercise enlarge (dilate) the blood vessels to the heart. Blood flow is then measured with an ECG test or with a radioisotope tracer that releases small amounts of radiation.

Before the test begins, electrodes are attached to your body. As the blood vessels dilate, the small amounts of radiation given off by the tracer are detected using a scanning camera. If there is narrowing in the heart’s vessels or they do not enlarge, the tracer to those areas of the heart is decreased. Areas with less “uptake” show up differently and are called defects. Two sets of images are used, one for baseline (rest), and the other (stress portion) to determine if a defect is present.

The entire radioisotope stress test takes three to four hours. You may have to return the next day to complete the test. The amount of radiation released is very small and safe. The stress portion of the test is generally safe, but there is always a small amount of risk when the heart is stressed with exercise or chemicals.

To prepare for the test, please follow these instructions as well as any other directions your doctor gives you:

  • No food or drink for at least six hours.
  • Mention any history of asthma or drugs for asthma, especially theophylline.
  • Do not take an medication containing theophylline for at least 48 before the test.
  • Do not drink any beverages that contain caffeine (coffee, tea, cola, or cocoa) for 24 hours before the test.
  • Tell your doctor if you are pregnant.
  • Write down any questions you may have so that you can ask them before the procedure.