Nuclear Stress Test

What is a Nuclear Stress Test?
Nuclear stress test is a noninvasive means of detecting the presence and/or significance of coronary artery disease. Coronary artery disease is a condition in which there is narrowing or blockage of the blood vessels supplying the heart muscle. This can cause chest pain which is known as angina pectoris.

Why is a nuclear stress test useful?
The most direct means of detecting the narrowing or blockage of a coronary artery is with coronary angiography. Since this is an invasive and expensive procedure, it is not practical to perform coronary angiography in every patient who is suspected of having coronary artery disease. On the other hand, nuclear stress test is noninvasive and less expensive, therefore it is more suitable for this purpose.

How is a nuclear stress test performed?
Nuclear stress test is an assessment of blood flow to the heart. This assessment is done in two parts, at rest and during stress.

Rest component of the test: A radioactive compound that localizes in the heart is injected in the vein of your arm, followed by the scan of your heart with the help of a gamma camera that detects the presence of the injected compound in your heart.

Stress component of the test: This component involves treadmill exercise. Before you start the exercise, several small electrodes (small pads) will be placed on your chest. These electrodes are then connected to an electrocardiograph (ECG) which monitors the rhythm of your heart. A second injection of the radioactive compound is given during exercise, and a second scan of your heart is performed.

How long does it take to perform a nuclear stress test?
After each injection, approximately 30 to 60 minutes time is allowed for the injection to distribute in the heart and to be cleared away from adjacent organs. Once the scan starts, it takes approximately 30 minutes.

What are the side effects?
The side effects can be divided in two parts: those due to injection of the radioactive compound and those due to the treadmill stress test.

Side effects of the injection of the radioactive compound: Some patients experience transient metallic or bitter taste immediately after the injection of Technetium sestamibi. Occasionally, headache and non-itching rash occur. Rarely, seizures, temporary joint pains, shortness of breath, slower heat rate and vomiting occur.

Side effects of the treadmill test: Chest pain, irregular heart rate and rarely, death have been reported during treadmill stress test. If you have any questions regarding this subject, please do not hesitate to ask questions to your physician or to the physician supervising your stress test.

If you are pregnant, suspect you may be, or are a nursing mother, please discuss this with your physician before scheduling the test.

What type of preparation is required for a nuclear stress test?

• You should not eat or drink for 3-4 hours before the test.
• Your physician may determine that certain medications may have to be stopped temporarily before the test to ensure the accuracy and effectiveness of the test.
• Since you will be exercising on a treadmill, it will help to wear comfortable clothing and footwear. If necessary, a hospital gown will be provided.