The cardiac perfusion scan, also known as heart perfusion test or heart perfusion scan, is a test undertaken to measure the blood levels in the heart during exercise and while the body is at rest. This test is mainly used to determine the possibility of heart disorders, heart diseases or causes of symptoms, such as chest pain. Cardiac perfusion scan may also be used to study the functioning of the heart after a heart attack. Conducting a cardiac perfusion scan after a heart attack helps determine the damage caused by the heart attack and also find areas of the heart that are not receiving enough blood.
The scan employs the use of a radioactive tracer. The radioactive tracer is a special test medicine that is injected into a vein in the arm. The tracer travels through the blood into the heart muscles while a camera takes pictures. The radioactive tracer is absorbed by areas that have good blood flow while areas without adequate blood flow are unable to absorb the tracer. Two sets of pictures are taken to indicate the blood flow after a stress test and while the body is relaxed. Two sets of images help compare the functioning of the heart in both situations.
The Myocardial perfusion thallium scan or nuclear medicine myocardial perfusion scan is a non invasive method used to determine the extent of heart diseases or damage to the heart. Chest pain and shortness of breath are problems associated with a weak functioning heart. The coronary artery which supplies oxygen to the heart muscles are unable to function normally due to blockages or narrow arteries giving rise to chest pain or palpitation. The Myocardial perfusion imaging stress test is conducted by injecting small amounts of thallium in the blood stream. The injected thallium can then be traced with the help of a special gamma camera as it travels through the arteries before, during and after exercise. The Adenoscan or adenosine myocardial perfusion imaging is employed if exercise is not advisable to the patient requiring a cardiac perfusion scan. In such a condition drugs such as adenosine may be administered to help increase the blood flow to the heart before injecting a radioactive tracer.
A cardiac perfusion scan takes only two to four hours. However, it not advisable for pregnant women to undergo this test, as injecting radioactive substances used while conducting the scan are not recommended for pregnant women. There are no risks or complications associated with this test. Some common problems that may arise include fatigue, muscle ache and angina. It is important to note that consumption of alcohol, caffeine, nicotine and other drugs or inadequate exercise after injecting the tracer can affect the test results