A cardiac amyloidosis scan or Tc-99m PYP/HDP imaging scan is an examination used to detect a certain type of cardiac amyloidosis called ATTR-CM (transthyretin amyloid cardiomyopathy). Transthyretin is a normal transport protein produced by the liver. When this protein becomes unstable, it becomes abnormal- it becomes an amyloid.
As these amyloids (abnormal proteins) build up over time in your heart muscle, the heart wall starts to thicken and become stiff. The resulting effect of this buildup is that the heart cannot pump effectively (cardiomyopathy) which may then lead to heart failure. Cardiac Amyloidosis can also affect the way electrical signals move through the heart which then produces abnormal heart beats called arrhythmias.
To diagnose cardiac amyloidosis and the presence of ATTR, Tc-99M PYP/HDP scan is performed.
Preparation for the Test
- **IMPORTANT** Please obtain your urine test 2 weeks prior to coming in for your PYP cardiac amyloidosis scan appointment. Results of the urine test are needed prior to proceeding with the cardiac amyloidosis scan.
- There are no special preparations or restrictions for the test. Wear comfortable clothes. You may eat, drink and take any of your medications prior to your test
What happens during the Test
- An intravenous (IV) line will be inserted into a vein in your arm by a nuclear medicine technologist
- A low level radioactive tracer called Technetium 99 PYP/HDP will be injected through the IV line. If there is amyloid tissue then this tracer will be absorbed by the heart muscle. Imaging will begin 1 hour and 3 hours after the injection to give proper time for the radioactive tracer to circulate. The images generally take 30min. In between imaging times, you may go out and eat, drink and take any medications with no restrictions.
Are there any side effects?
- Because the injected medications contain only a minimal amount of the carrier drug, there are no significant side effects. The radioactive tracer used during the Tc99m PYP/HDP scan is a diagnostic dose of radiation that is similar to the dose you would receive during a CT scan.
How long will it take to complete the test?
- 2 sets of images at 1 hour and 3 hours post-injection will be taken. The images usually take 30 minutes. In between imaging times, you may go out and eat, drink and take any medications with no restrictions.