What is a thallium stress test?  

A Thallium stress test is a nuclear medicine scanning procedure that allows the cardiologist to look for blockages in the (heart) coronary arteries.  The nuclear camera takes images of the heart and projects them onto a computer screen. These images show blood flow to the heart muscle which indicates the strength or weakness of the heart.

What will I be doing during the test?

During the thallium stress test, images of the heart are taken both during exercise and rest.  To exercise the heart, patients usually walk on a treadmill.  If exercise is not feasible or recommended, a small dose of medication is given to increase the heart rate or blood flow to the heart. 

The first pictures of the heart are taken after the patient receives a small dosage of thallium.  Thallium is an isotope that clings to the heart muscle and allows the nuclear camera to see images of the heart.

Thallium is extremely safe and there are no known adverse or allergic reactions. The patient lies on a table under the camera for approximately 15 minutes while the camera circles around them and records information. Next, the patient is exercised on the treadmill or given a dose of medication to increase the blood flow.  The doctor monitors the patient’s blood pressure during the exercise and makes sure that the patient reaches his/her maximum level of exercise.

After exercise levels have been reached, the patient receives another small injection of technitum, another radio isotope, and again lies down under the camera. Images of the heart after exercise are then taken.   

What does the thallium stress test show?

•  If blood flow to the heart is not blocked after exercise and rest, then the coronary arteries are normal.
• If the test shows that blood flow is normal during rest, but abnormal during exercise, then the heart is not receiving enough blood when it is working harder than normal.  This may be due to a blockage in one or more of the coronary arteries.
• If the test is abnormal during both exercise and rest, there is limited blood flow to the patient’s heart at all times.  This could suggest a prior heart attack. 
• Your cardiologist will review the results of your thallium stress test with you as soon as the test is complete and the pictures are developed.  They will advise you of treatment options if your test is abnormal.   

How to prepare for your Thallium Stress Test. 

• It may be a good idea to bring something to read or occupy your time in between the various portions of the test.  You may be at the office for as long as 4 hours.
•  Please arrive at least 15 minutes early to fill out  paper work if you are a new patient or if your insurance information has changed. 
•  No caffeine or de-caffeinated drinks for 24 hours prior to your test time– drink water, juice, or milk. 
• No solid foods for 3 hours before your test. If you are scheduled for an afternoon test, try to have breakfast at least 3 hours prior to your test.

For 24 hours before the test, do not take the following medications:

Beta Blockers such as: Toprol XL, Metoprolol,   Lopressor, Coreg, Atenolol, Tenormin.

Calcium Blockers such as: Tiazac, Cardizem CD, Diltiazem, CD, Cartia Verapamil, Calan, Cardizem LA.

Nitrates such as: Imdur, Isosorbide, Nitropatch.

No Excedrin.

• If you are taking other medications for your heart or if you are a diabetic, please check with your doctor before taking medications on the day of the test. 
• You may bring a light snack to have after the stress portion of the test.
• Wear loose comfortable clothing and sneakers with rubber soles.  No flip flops or open toe shoes. Do not wear shirts or blouses with metal buttons or zippers.
• Please notify our office if you are severely claustrophobic.
• Since there are no adverse side effects from the thallium stress test, you will be able to drive immediately following.
• The test is conducted at all 6 of our office locations.