Patient education: Nuclear heart testing (The Basics)

What is nuclear heart testing? — 

This is an imaging test to check how healthy the heart is. It can show:

●How much blood flows to the heart muscle

●How well the heart pumps blood to the rest of the body

Usually, people have a test called a "stress test" along with a nuclear heart test. This measures how well the heart works when it is under stress. A nuclear heart test shows if the heart gets enough blood during these times. When both tests are done together, it's called a "nuclear stress test." Doctors also use the term "myocardial perfusion imaging."

Why might I get a nuclear heart test? — 

Your doctor might order a nuclear heart test or a nuclear stress test to:

●Check if your heart muscle is getting enough blood

●Look for certain heart conditions, or check on a known heart condition

●Check your heart after a heart attack or heart surgery

●See how well your heart pumps blood to the rest of your body

How do I prepare for a nuclear heart test? — 

The doctor or nurse will tell you if you need to do anything special to prepare.

Before the test, your doctor will:

●Do an exam

●Ask about all the medicines you take – They might have you stop or change some medicines before the test.

●Tell you when to stop eating and drinking before the test (called "fasting") – They might also ask you not to drink anything that has caffeine in it for 24 hours beforehand.

If you are pregnant, tell your doctor before you have a nuclear heart test. They might suggest a different test or delay the test until after you give birth.

What happens during a nuclear heart test? — 

First, you will get a test called an "electrocardiogram" ("ECG"). This records your heart rate and rhythm by measuring the electrical activity in your heart (figure 1).

Then, you will lie down on a table. The staff will put a thin tube called an IV into your arm and put a radioactive substance, called a "tracer," into it. The tracer will travel through your blood to your heart. A camera outside of your body will record the tracer's signals. A computer will use these signals to create images of blood flowing to and through your heart.

If you have a nuclear stress test, you will usually have 1 set of pictures done while you rest, and another set done when your heart is under stress. Some people might only have the pictures done once. To "stress" your heart, the doctor will do 1 of the following:

●Have you run or walk on a treadmill (figure 2)

●Have you pedal a stationary bike – This is an exercise bike that doesn't move, except for the pedals.

●Give you medicine to make your heart pump faster or widen your heart arteries – This is for people who cannot exercise.

After the stress test, the doctor will take another set of pictures. That way, they can compare the results from the 2 different times.

Some nuclear heart tests do not require exercise. In this case, pictures are only taken while you rest.

What happens after a nuclear heart test? — 

Your doctor or nurse will review the results and tell you what they mean. If there is a problem or if you need treatment, they will discuss your options with you.

What are the risks of nuclear heart tests? — 

Nuclear heart tests do involve a small amount of radiation. Too much radiation can cause serious health problems, like cancer. The amount of radiation in a single nuclear heart test will not cause any long-term problems in most people. But your doctor should talk with you about the possible long-term side effects of radiation.

Other risks can include:

●Pain or redness where the IV went into your arm

●Side effects from the stress test – Symptoms might include chest pain, trouble breathing, abnormal heartbeat, or feeling dizzy or faint.

More on this topic

Patient education: ECG and stress test (The Basics)
Patient education: Chest pain (The Basics)
Patient education: Heart attack (The Basics)
Patient education: Coronary artery disease (The Basics)
Patient education: Heart failure (The Basics)

Patient education: Chest pain (Beyond the Basics)
Patient education: Heart attack (Beyond the Basics)
Patient education: Heart failure (Beyond the Basics)