What is the purpose of a myocardial perfusion scan?

Nuclear stress test: This is a specialized form of stress test used to confirm the presence of coronary artery disease in patients suspected of having this problem. It uses a low-level nuclear tracer to assess blood flow to the heart muscle before and after exercise-induced stress. In patients who cannot exercise, other pharmacologic means can be used such as adenosine, lexiscan, persantine, or dobutamine.

Assess risk: 1. Determine blood flow to the heart at rest and at stress. The difference between these two can help determine risk of a major cardiac event such as a heart attack. 2. Determine cardiac size. 3. Determine cardiac function (left ventricular ejection fraction). 4. Determine exercise capacity. 5. Determine electrical (ECG) response to stress. These factors are used to help guide medical therapy.

Cardiac blood supply: A cardiac perfusion scan measures the amount of blood supplied to your heart muscle. Radiotracers such as thallium or technetium sestamibi are injected intravenously and travel through blood to heart muscle. Two sets of images are made during rest and exercise and compared. Indications for this study include chest pain, previous heart attack, heart surgery and coronary artery disease.