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)
effects of certain medications
Other related procedures that may be used to assess the heart include: