Nuclear / Isotope Stress Test
(Myocardial Perfusion Imaging):

• How does an Isotope Stress test work:
  When the patient has the regular stress test, and has clogged arteries, leading to the reduction in blood flow to a specific area in the heart muscle? This area will show evidence of starvation by symptoms or EKG changes. Other modalities will help to identify this problem more definite, even in those who are having silent narrowing and abnormal blood flow, such as a nuclear isotope that travel to heart muscle with blood flow, extracted by the heart muscle in proportion to the blood flow delivered to that area. The tracer uptake by the muscle then will be projected into special electronic pictures, identify the healthy heart muscle from the diseased one.
   

• How is nuclear stress test performed?
  The test is divided into three parts:

• Imaging at rest: The perfusion tracer or isotope will be injected in the IV, which was put in before the test start. Then patient is placed under the scanning camera.

• Stress test (Treadmill or pharmacological): The perfusion tracer or isotope is injected 1.5 minutes prior to the termination of the stress test, to allow the tracer to be taken up by the heart muscle.

• Imaging after stress test: These images are taken to compare it with the resting images.

• All pictures or images are fed into a computer to reconstruct them as slices of the three dimensional heart.

• The images then will be studied by a qualified physician to identify disease heart muscle and also to have a good idea about the function of the heart including contractility.

• How long does the entire test take?
  Approximately two to four hours should be considered for the entire test, including the preparation.
   

• How safe is an isotope stress test?
  The patient is exposed To a very small amount of radiation and the risk is very minimal, if any.
   

• What is the reliability of an isotope stress test?

• With good exercise and good images, this test is capable to diagnose heart disease in 855 of patient with narrowing arteries.

• Approximately 10% of patient may have a false positive test.

• Women could have abnormal images in the front part of the heart because of overlying breast tissue.

• Men could have abnormal findings in the lower portion of the heart because of a prominent diaphragm

• Patient who have a left bundle branch block in their EKG (abnormal electrical conduction in the heart) could have also a false abnormal test.