What Is a Resting and Exercise Radionuclide Angiogram (RNA)?
Resting and exercise radionuclide angiogram (RNA) is a type of nuclear medicine procedure. This means that a tiny amount of a radioactive substance, called a radionuclide (radiopharmaceutical or radioactive tracer), is used during the procedure to assist in the examination of the tissue under study. Specifically, resting RNA evaluates the heart's chambers in motion.
MUGA/radionuclide angiography uses radioactive imaging to view blood flow, internal organ structure, and organ function, including how the heart wall moves and how much blood is expelled with each heartbeat, while the patient is at rest.
A radionuclide (usually technetium) will be injected into an arm vein to "tag" the blood cells so their progress through the heart can be traced with a scanner.
A special camera (gamma camera) will make recordings of the heart wall at work, like a motion picture. These recordings will be synchronized with the heartbeat by using the electrocardiogram (ECG, or recording of the heart's electrical activity).
A cardiologist (a physician who specializes in heart disease) trained in nuclear cardiology will study the films to evaluate the heart's pumping function and ejection fraction (the volume of blood pumped out with each heartbeat).
An RNA procedure with rest and exercise is performed to assist the physician in assessing the heart's function during exercise after comparing it to the heart's function at rest.
If the heart muscle does not move in a normal manner, and/or a less-than-normal amount of blood is pumped out by the heart, this may indicate one or more of the following:
Injury to the heart muscle, possibly as a result of decreased blood flow to heart muscle due to clogged coronary arteries
An enlargement of one or more of the heart's chambers
Aneurysm (a weak spot in the heart muscle)
Toxic effects of certain medications
Other related procedures that may be used to assess the heart include: