Nuclear Medicine Cardiac Stress Test

Dr Ghee Chew*
                            Dr Timothy Cain *

What are the prerequisites for having a NM cardiac stress test done?

There are no prerequisites for this study.

What are the absolute contraindications for a NM cardiac stress test?

This study may not be suitable for pregnant women. The benefit versus risk should be discussed with the nuclear medicine specialist.

Women who are breastfeeding and people who are the primary or sole carer for small children may need to make special preparations after the test to stop breastfeeding for a short time and to avoid close contact with young children due to the small amount of radioactivity released for a while after the test. Patients should discuss this with their referring doctor or the nuclear medicine practice where they will have the test for details. See nuclear medicine for further information about the precautions to take with nuclear medicine studies for breastfeeding patients and those in close contact with children.

Known allergy to any of the pharmacological stress agents is an obvious contraindication.
More specific contraindications for dipyridamole and adenosine:

  • asthma and chronic airways limitation with a significant bronchospastic component;
  • 2nd and 3rd degree AV block and sick sinus syndrome without an artificial pacemaker.

Caution is exercised when using dobutamine in patients with suspected tendency to ventricular tachyarrythmias and in patients with atrial tachyarrythmias (particularly if not on anticoagulation).

What are the relative contraindications for a NM cardiac stress test?

There are no relative contraindications for the NM Cardiac Stress Test. Even in claustrophobic and obese patients, whose weight exceeds the limits of the imaging bed, can be scanned with patient sitting up and 2 dimensional (planar instead of tomographic) images acquired.

The contraindications of the pharmacological stress agents are outlined above.

What are the adverse effects of a NM cardiac stress test?

The likelihood of an adverse reaction to the radiopharmaceutical is very remote, in the order of 1 in 10,000. The likelihood of a serious allergic event is even less likely. The adverse effects of the pharmacological stress agents are outlined above.

Are there alternative imaging tests, interventions or surgical procedures to a NM cardiac stress test?

The alternatives to NM cardiac stress tests are:

  • Exercise stress test only – lower accuracy compared to the addition of the nuclear scan and cannot be performed in patients who are unable to exercise to an adequate level.
  • Stress echocardiogram – similar to the nuclear scan, accuracy is dependent on the expertise of the sonographer or technical staff and the cardiologist interpreting the echocardiogram.
  • Cardiac CT – relative contraindication in renal failure. Scan quality reduced in patients whose heart rate cannot be adequately reduced.
  • Cardiac MRI – contraindications of MRI applies. Relative contraindication in renal failure.
  • Coronary angiogram – invasive with higher risks. Relative contraindication in renal failure.

Further information about NM cardiac stress test

Relevant to clinical practice, the NM cardiac stress test:

  • Has ample clinical data to support its role in the prognostication of coronary vascular events, which assists the clinician in determining the need for further investigations and the tailoring of medical therapy.
  • Is a physiological examination of net blood flow to each coronary vessel territory, and has a complementary role to the other imaging modalities which evaluate the coronary vascular anatomy.
*The author has no conflict of interest with this topic.

Page last modified on 21/7/2017.

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