What Is a Myocardial Scintigraphy?

Myocardial scintigraphy provides images of the heart, allowing a doctor to evaluate blood flow. A cardiologist may request this test as a diagnostic tool or in a patient assessment to determine the response to treatment. The study may be useful for developing treatment plans for certain conditions. It takes place in a medical imaging center, and may take an hour or more to complete. Patients may want to arrange a day off from work or school in case of delays or discomfort after the test that might make it difficult to resume ordinary activities.

In this medical imaging study, a technician injects a small amount of a radioactive tracer material. The patient rests while it has a chance to circulate, and then lies under a gamma camera. A series of pictures follow the tracer as it moves through the heart, providing information about the level of blood flow available to the heart muscle. Doctors can ask for a rest-stress test, where the myocardial scintigraphy is performed on a resting patient and again while the patient exercises, to look at the differences between the two.

Patients usually need to rest for around half an hour to allow the tracer to fully circulate before the imaging of the heart can begin. If a rest-stress test is required, the patient may need to wait between tests to allow the team to collect clear, useful images. Throughout the procedure, the patient is monitored for signs of distress, and the test can be stopped at any time. Patients with severe heart conditions may be at risk when the heart is under stress, and thus may require special care.

A very small amount of radiation is involved in myocardial scintigraphy, and it is usually safe for patients. People who have had a number of nuclear imaging studies may be at greater risk, as are those with certain allergies. Before the test, the doctor may request a medical history to identify any risk factors. The care providers who perform the myocardial scintigraphy may have additional questions to screen the patient further. If there are concerns, they may recommend waiting or pursuing a different test to collect this information.

Depending on the facility, myocardial scintigraphy results may be available immediately. The doctor can discuss them with the patient and recommend next steps, which may include other diagnostic testing or treatments. In other cases, the doctor may want time to look at the test results before meeting with the patient, and could request a follow-up appointment to talk about them. This is ideal when the myocardial scintigraphy uncovers an immediate and life-threatening emergency, as the patient will be able to receive prompt care.