A radioactive isotope called technetium is injected into your vein. Radioactive isotopes attach to red blood cells and pass through the heart in the circulating blood. The radioactive isotope can be traced through the heart using special cameras or scanners. The images may be combined with an electrocardiogram.

You will be tested when you are resting, then tested again with exercise or after you take certain medications.

You may be�told not to eat or drink�beverages containing caffeine or alcohol for several hours before the test.

You may feel a brief sting or pinch when the IV is inserted. You may have trouble staying still during the test.

The test will show how well the blood is pumping through the heart, and will check for clogged arteries.

Normal results indicate normal heart function, or a normal cardiac response to exercise.

Abnormal results may indicate poor pumping function, a prior heart attack (myocardial infarction), blockages in the coronary arteries (coronary artery disease), heart valve disease, or other cardiac disorders associated with weakening of the heart function.

Additional conditions under which the test may be performed:

• Atrial septal defect
• Dilated cardiomyopathy
• Heart failure
• Idiopathic cardiomyopathy
• Mitral stenosis
• Peripartum cardiomyopathy
• Senile cardiac amyloid

Nuclear imaging tests carry a very low risk of complications. Exposure to the radioisotope is safe for patients undergoing an occasional nuclear imaging test.