The nuclear stress test is a medical procedure performed to help a doctor to evaluate the heart for blocked arteries. It is a common cardiovascular test to determine the possibility or extent of coronary artery disease.

The Stress Test

The stress test is designed to measure blood flow to and from the heart. This is done while the patient is resting and doing physical activity.

Stress test.Credit: Public demain per BlueOctane

The stress test is done on a treadmill, bicycle or stationary exercise machine. The treadmill allows the operator to vary speed, or increase or decrease the elevation angle. Before the test the operator attaches electrodes to the patient’s body for the electro cardiogram (ECG or EKG). The purpose is to increase the patient’s heart rate. While the test progresses, the heart rate, blood pressure and ECG are continuously monitored. As the heart rate reaches  various stages, the operator prints a section of the ECG. A person’s age determines what the highest heart rate to check. The older the patient, the lower the maximum heart rate required for the test.

The Nuclear Stress Test

The treadmill portion of the test is the same as the treadmill test. It is about a 2 hour test and the amount of time on the treadmill is about a quarter of an hour. The difference with the nuclear stress test is the addition of nuclear material in the veins. A nuclear solution is injected into a vein. This allows observation of how the heart is operating as the solution goes through the heart. After specified amount of time, an operator takes an x-ray. Combined with the stress test, it allows seeing how the heart operates in more situations. The final test portion is a series of pictures taken by a gamma camera. The patient lays on a table and must remain still. This takes about 20 minutes. The camera rotates and takes pictures from different angles.


Before the test the physician gives instructions what to do before the cardiovascular test. They may deviate from those listed here.These instructions include, items not to eat or drink, whether to take medications, and don’t smoke before the test. The doctor will inquire to medications and supplements the patient is taking. It’s a good idea to take a book to read during the waiting times between exercise and the medical photographs.

This test isn’t hard. Wear comfortable shoes and loose clothing for the exercise portion. It is a test that reveals coronary artery anomalies to give the physician a better opportunity to see if there are any problems. It is a complete test that can illuminate problems with heart blood flow or muscles. If the nuclear cardiovascular test is uncertain, or raises other questions, the doctor may recommend an angioplasty, a test done in the hospital.