Myocardial perfusion imaging is a non-invasive imaging testing modality that shows how well the blood flows through (perfuses) your heart muscle. It can show areas of the heart muscle that are not getting enough blood flow and can lead to symptoms such as chest pain or shortness of breath. We combine myocardial perfusion images with exercise (walking on a treadmill) to assess the blood flow to the heart muscle. We perform a chemical or pharmacological stress test using the drugs regadenoson, dipyridamole, adenosine or dobutamine in patients who are unable to exercise maximally. This approach provides similar information about the heart's blood flow.
We inject a small amount of an imaging agent Tc-99m sestamibi or Thallium, into the blood stream during rest and during exercise or chemical stress. Then we use a scanning device (gamma camera) to measure the uptake of the imaging agent in the heart during stress and at rest. If there is significant blockage of a coronary artery, your heart muscle may not get enough blood when you are exercising or during chemical stress. The imaging tests can show this decrease in blood flow.
Myocardial perfusion studies can identify areas of your heart muscle that are not getting enough blood as well as the areas that are scarred from a heart attack. We can also see where your coronary artery may have atherosclerosis (hardening or narrowing), how much of your heart is not getting enough blood, and how well your heart is pumping. This information helps us identify whether you are at an increased risk and may be a candidate for invasive procedures such as coronary angiography, angioplasty, or heart surgery.
When your heart is inflamed or does not receive enough blood, it can irreversibly affect the basic cellular component of the heart muscle. Nuclear cardiology techniques can help us determine which areas of the heart muscle have been damaged by infection or by a heart attack. These techniques can also help us monitor your heart after cardiac transplantation.