Radioisotope Treadmill Test: Understanding Nuclear Stress Tests

A radioisotope treadmill test, also called a nuclear stress test, is a procedure to analyze heart function and diagnose potential heart ailments including the death of heart muscle tissue.

Before Testing

• Before a nuclear stress test begins, a doctor attaches electrodes that measure the heart's electrical activity, to the patient's chest, according to the Mayo Clinic. These electrodes feed information to an electrocardiogram machine, which records the generated data.

Stress Testing

• In the test's first phase, the patient exercises on a treadmill or stationary bicycle to stress the heart muscle and provide information for the electrocardiogram.

Active Scan

• When the patient reaches his maximum exercise tolerance, the doctor injects a radioactive dye into a vein. Once this dye travels to the heart, the doctor takes images of the heart muscle using a specialized scanner.

Resting Scan

• After this first scan, the patient rests for two to four hours, the Mayo Clinic reports. The radioisotope procedure is then repeated to record images of the heart in its resting state.

Significance

• Areas of the heart that do not register on a radioisotope scan have likely died from blood supply loss or a previous heart attack, according to the Texas Heart Institute.