Myocardial perfusion imaging (nuclear stress test) Diagnostic Imaging

Myocardial perfusion imaging is a heart test that uses a small amount of a radiotracer (a substance that gives off a tiny amount of radiation) and a special camera to show blood flow to the heart muscle.

Myocardial perfusion imaging (nuclear stress test) procedure illustration

Overview

Myocardial perfusion imaging is a heart test that uses a small amount of a radiotracer (a substance that gives off a tiny amount of radiation) and a special camera to show blood flow to the heart muscle. Pictures are taken at rest and during stress, either with exercise on a treadmill or with medicine that makes the heart work harder. This test helps find areas of the heart that do not get enough blood, which can point to blocked arteries. It can also show scar from a past heart attack and help teams plan treatment or check how well treatment is working.

Overview Preparation Clinical Info Recovery FAQ References

Also known as: Nuclear stress test, Myocardial perfusion scan, SPECT stress test, PET perfusion scan

Recovery
0–1 days
Return to Work
0–1 days

Preparation & Next Steps

Everything you need to know before and after your procedure

Before Care

  • Bring a current list of your medicines and supplements, including over-the-counter items and caffeine sources.
  • Follow the testing center’s instructions about not eating or drinking (except water) for a set time before the test.
  • Avoid caffeine if told to do so; it can interfere with stress medicines used during the test.
  • Wear comfortable clothing and walking shoes in case exercise stress is used.
  • Confirm how long the appointment may take; parts of the test may be spaced over several hours.
  • Tell the staff ahead of time about allergies, past reactions to contrast or tracers, asthma, or heart rhythm problems.
  • Tell the team if there is any chance you are pregnant or if you are breastfeeding so they can review options.
  • Ask how to handle diabetes medicines or inhalers for the day of the test; bring needed supplies with you.
  • Bring prior heart test results or images if available to help with comparison.
  • Arrive early to complete forms and set up an IV line for the tracer.

After Care

  • Plan to drink water during the day unless you were told otherwise; fluids help your body clear the tracer.
  • You can usually eat your normal meals after the test unless the center gives different instructions.
  • Keep the IV site clean and dry; mild soreness or bruising can happen and often improves within a day.
  • Resume normal daily activities as you feel able unless the care team gives different instructions.
  • If a medicine was used for stress, mild flushing, headache, or nausea usually fades within hours.
  • Avoid new strenuous exercise the rest of the day if you feel tired from the test.
  • Some centers advise limiting prolonged close contact with infants or pregnant people for several hours; guidance varies by center.
  • Ask when and how results will be shared; many centers provide a report within a few business days.
  • Contact the testing center or your clinician if you develop chest pain, trouble breathing, fainting, spreading redness or swelling at the IV site, hives, or a fever.

Clinical Information

Important medical details about this procedure

Indications

  • Chest pain, pressure, or shortness of breath where coronary artery disease is suspected
  • Abnormal or unclear exercise treadmill test
  • Risk check after a heart attack or before certain surgeries
  • Evaluation of known coronary artery disease
  • Assessing cause of new or worsening exercise limits
  • Checking results after stent or bypass surgery
  • Clarifying unclear ECG changes

Alternatives

  • Exercise treadmill test without imaging
  • Stress echocardiogram (ultrasound of the heart during stress)
  • Coronary CT angiography
  • Cardiac MRI perfusion study
  • Invasive coronary angiography

Risks

  • Exposure to ionizing radiation from the radiotracer
  • Side effects from stress medicines such as flushing, headache, chest discomfort, or shortness of breath
  • Abnormal heart rhythm or low blood pressure during stress
  • Allergic or injection-site reaction to the tracer or IV contrast (rare)
  • Nausea or dizziness during or after the test
  • Very rare risk of heart attack during stress testing

Contraindications

  • Suspected or recent heart attack or unstable chest pain not yet evaluated
  • Uncontrolled abnormal heart rhythms or severe aortic valve narrowing
  • Severe active wheezing or uncontrolled asthma when certain stress medicines are used
  • High-grade heart block without a pacemaker for certain stress medicines
  • Pregnancy unless the expected benefit clearly outweighs risks

Recovery Timeline

What to expect during your recovery

Most people return to normal activities the same day. Tiredness or mild symptoms from stress medicine usually resolve within hours.

Typical Range

0–1 days

Return to Work

0–1 days

Recovery Milestones

Day 0

Resume light daily activities after leaving the imaging center

Day 0–1

Drink water regularly to help clear the tracer

Day 0–1

Return to work or school if you feel well

Day 0–2

Check your portal or phone for test results as advised

Frequently Asked Questions

Common questions and expert answers about this procedure

What does a nuclear stress test show?

It shows how well blood flows to your heart muscle at rest and during stress. Areas with low blood flow may point to narrow or blocked arteries.

How long does the test take?

Plan for several hours. Images are taken at rest and again after stress, with waiting periods between tracer injection and camera scans.

Do I have to walk on a treadmill?

If you can exercise, a treadmill is often used. If not, a medicine can make your heart respond as if you were exercising.

What is the difference between SPECT and PET?

Both use radiotracers. SPECT is more common and widely available. PET can offer clearer pictures and shorter scans at some centers.

Why avoid caffeine before the test?

Caffeine can block the effect of stress medicines and make results less accurate.

Is the radiation safe?

The test uses ionizing radiation. The amount varies by tracer and camera. The goal is to use the lowest dose that gives good images.

When will I get results?

A cardiologist or nuclear medicine physician reviews the images and sends a report, often within a few business days.

Can I drive myself home?

Most people can drive after the test. If you feel unwell or very tired, consider arranging a ride.