What is a Stress Echo?

An echocardiogram (often called "echo") is a graphic outline of the heart's movement, valves and chambers, using high-frequency sound waves that come from a hand-held wand placed on your chest. Echo is often combined with Doppler ultrasound and color Doppler to evaluate blood flow across the heart’s valves. The exercise stress echo test involves exercising on a treadmill or an intravenous infusion of a medication called Dobutamine (medication that exercises your heart) while you are closely monitored. The test is used to evaluate your heart and valve function at rest and with exertion.

What is a stress echo used for?

• Determine if there is adequate blood flow to your heart during increasing levels of activity
• Evaluate the function of your heart and valves at rest and during activity
• Determine your likelihood of having coronary artery disease (blocked arteries)
• Evaluate the effectiveness of your cardiac treatment plan

What can I Expect?

DO NOT eat or drink anything except water for four hours before the test.

Bring your medication with you on the day of the test. Your physician may also ask you to stop taking other heart medications on the day of the test. If you have questions about your medications — ask your physician. Do not stop any medication without first talking with your doctor.

If you have diabetes and take medications to manage your blood sugar, ask your physician how to adjust your medications the day of your test. Do not take your diabetes medication and skip a meal before the test. If you think your blood sugar is low, tell the lab personnel immediately. Plan to eat and take your blood sugar medication after your test.

If you use an inhaler for breathing, bring it to the test.

Wear comfortable clothes. Bring shoes suitable for walking. You will need to change into a hospital gown to wear during the procedure. You will be given a locker to store your belongings during the test. Do not bring valuables.

Before the test, a cardiac sonographer (an allied health professional who has been trained specifically to perform ultrasound examinations), nurse or physician will explain the procedure in detail, including possible complications and side effects. They will be available to answer any questions you may have.

First, the sonographer will gently rub ten small areas of your chest, and place small sticky electrode patches to these areas. The electrodes are attached to an electrocardiograph (ECG) monitor, which charts your heart’s electrical activity during the test.

Before you begin to exercise, the sonographer will perform a resting ECG, measure your resting heart rate and take your blood pressure.

The sonographer will ask you to lie on your left side on an exam table so he or she can perform a resting echo. The sonographer will place a wand (sound-wave transducer) on several areas of your chest. The wand will have a small amount of cool gel on the end, which will not harm your skin and helps get clearer pictures of the heart's movement. Sounds are part of the Doppler signal so you may hear the sounds during the test.

You will exercise either on a treadmill or be given a medication called Dobutamine through an IV, to exercise your heart if you cannot walk on the treadmill. The lab personnel will ask you to start exercising and gradually increase your rate of exercise. You will be asked to exercise very hard until you are exhausted. It is normal for your heart rate, blood pressure, breathing and perspiration to increase. This information will allow your physician to assess your heart's ability to function.

At regular intervals, the lab personnel will ask how you are feeling. If you feel chest, arm or jaw pain or discomfort, short of breath, dizzy, lightheaded, irregular heart beats or if you have any other unusual symptoms, tell the stress lab personnel immediately.

The lab personnel will watch for changes on the EKG monitor that suggest the test should be stopped.

When you cannot exercise any longer:

• You will get off the treadmill, quickly return to the exam table and lie on your left side so the sonographer can perform another echocardiogram. It is normal to feel a little unsteady when getting off the treadmill and onto the exam table for the echo, as you stop exercising suddenly.
• If you were given Dobutamine, the sonographer will perform the echo test several times while the medication is running until your target heart rate (number based on your age) is reached, and then the medication will be turned off.
• Your heart rate, blood pressure and EKG will continue to be monitored after exercising until the levels are returning to normal.

The appointment takes about 60 minutes. The actual exercise time is usually between 7 and 12 minutes.

After the cardiologist reviews your test, the results will go into your electronic medical record. Your physician will have access to the results and will discuss them with you. Ask you doctor if you have any questions about the echocardiogram.

Pharmacologic Stress Testing

What is a Pharmacologic Stress Test?

A test used to provide information about how the heart responds to stress. It utilizes a medication (Adenosine or Dobutamine) to ‘exercise’ your heart while the electrocardiogram, heart rate and blood pressure are monitored. It is used in patients who are unable to exercise on a treadmill or stationary bicycle.

What is a Pharmacologic Nuclear Stress Test used for?

• To determine if there is adequate blood flow to your heart during increasing levels of activity

What is Adenosine?

• Adenosine is a potent coronary vasodialator which increases coronary blood flow
• Adenosine does not provoke ischemia
• In coronary artery disease, resistance vessels distal to stenosis are already maximally dialate
• Adenosine causes a “Reverse Robin Hood Effect”
  • Blood flow in normal arteries increases 10 times normal
  • diseased arteries cannot increase blood flow any more and are ‘relatively’ under-perfused in relation to normal arteries
  • This shows up as a perfusion defect or area of ischemia on the nuclear blood flow scan

What is Dobutamine?

• Dobutamine is a medication that increases heart rate and blood pressure similar to the effect of exercise.