DOBUTAMINE NUCLEAR STRESS TEST

Your physician has ordered a cardiac nuclear stress test. This test is performed for many reasons. It is done to identify the cause of chest pain or chest discomfort which can occur with blockages in blood flow to the heart, to monitor heart function in people with known heart disease, and to determine the response to medications or after angioplasty or bypass surgery. The nuclear stress test also involves taking pictures, also known as images, of your heart. A radioactive substance, known as a tracer, is injected into a vein in your hand or arm and travels in the bloodstream to the heart. Areas of the heart receiving adequate blood flow pick up the tracer more completely.

Your physician has determined that you would not be able to perform an exercise test, such as walking on a treadmill well enough to stress your heart adequately. As a result, a pharmacologic or medicated stress test must be performed. The drug, Dobutamine, is used to stress the heart without exercise. Dobutamine has the effect of increasing the force of contraction of the heart, the heart rate and blood pressure. This stresses the heart muscle, which simulates exercise. When combined with the administration of Dobutamine, the pictures can detect areas of the heart that are not receiving enough blood flow. This enables your physician to determine your heart’s response to stress. The results assist the physician in managing your cardiac condition.

A 24 hour notice of cancellation is required. The radioactive tracer material for your test is ordered in advance and is delivered daily. It is not reusable. You may be responsible for the cost of the material if you fail to cancel.

How do I prepare for the Dobutamine nuclear stress test?

• Do not eat anything 2 hours before the test.
• Some “over the counter” medications such as Excedrin contain caffeine – please check the label for ingredients.
• Do not smoke or use any form of nicotine 12 hours prior to your test.
• If instructed by your physician, do not take Beta Blockers or Calcium Channel Blockers for 24 hours prior to the test. (A list of these medications is attached).
• Take your medications (other than those listed above) on the day of the test unless instructed otherwise.
•  Failure to comply with the above directions will require your test to be rescheduled.
• Do not apply lotions or powders to the chest.
• Wear loose, comfortable clothing: ladies may want to wear a front-buttoning, short sleeve shirt.
• Ladies should not wear underwire bras, if possible. Underwire bras must be removed for the imaging portion of the test.

What happens during the Dobutamine stress test?

            Rest Portion

• You will be given an explanation of the test and asked to sign a consent form.
• A registered nuclear medicine technologist inserts an intravenous catheter into your hand or arm.
• A small amount of radioactive material, called a tracer, is injected through the intravenous catheter.
• You lie flat on a special table under a large scanning camera.
• The camera takes pictures, called images, of your heart from many angles.

Stress Portion

• Electrodes are placed on your chest and connected to an electrocardiogram (ECG) machine, which permits continuous monitoring of your heart rhythm.
• A nurse supervises the stress portion of the test.
• Your blood pressure is checked frequently, and your ECG is continuously monitored.
• Dobutamine is administered through the intravenous catheter in increasing doses
• Near the end of the infusion of the Dobutamine a second tracer is injected into the intravenous catheter.
• It is common to experience the sensation of heart pounding or racing with Dobutamine.
• Report any symptoms, such as chest pain, shortness of breath, or dizziness.
• When the stress portion is completed, your blood pressure and ECG will be monitored for several more minutes.
• You lie under the camera for a second set of images.

Please allow 2 ½ – 3 ½ hours for the entire test to be completed.

When will I know the results of the stress test?

• Final interpretation of the test results is completed by a cardiologist with a specialty in nuclear cardiology.
• The physician ordering your test and/or your primary care physician receive a report within approximately 3-5 days.

Medications which affect Dobutamine Stress Tests

Must be off a minimum of 24 hours prior to test

Beta Blockers

Betapace (sotalol)

Blocadren (timolol)

Cartrol (carteolol)

Coreg (carvedilol)

Corgard (nadolol)

Inderal (propranolol)

InnoPran XL (propranolol)

Kerlone (betaxolol)

Levatol (penbutolol)

Lopressor (metoprolol)

Rythmol (propafenone)

Sectral (acebutolol )

Tenormin (atenolol)

Toprol XL

Trandate, Normodyne (labetolol)

Visken (pindolol)

Zebeta (beisoprolol)

Or combinations