Nuclear scan of the heart

The nuclear heart scan is non-invasive imaging. In this method, a type of radioactive detector is injected into the blood and produces images of your heart. Doctors use nuclear heart scans to diagnose coronary artery disease and to report a heart attack. This method can show how the blood goes to the heart and how the heart works. Cardiac scans can also provide information about the accurate amount of heart pumping.

Reasons for a nuclear heart scan demanding

Nuclear heart scans show parts in your heart where blood flow is reduced when resting or during exercise. This information will help your doctor understand the following:

• Coronary Artery Disease
• Heart attack and damaged areas of heart tissue
• Quality of bypass surgery or other cardiac procedures
• The necessity for more immediate tests, such as a heart angiogram or percutaneous coronary intervention (PCI)
• The possibility of a heart attack in the future

How to do a nuclear heart scan 

A radioactive tracer is injected into your blood. Inside your body, the detector generates a type of energy called gamma rays. A gamma camera receives tracker signals then the computer converts them into images. Images of thin parts heart are taken from different angles. The doctor will check These images for the location of the radioactive tracer. To create a three-dimensional image of the heart, the device uses a computer to put thin parts of the heart together. In the resulting images, parts of your heart that show good blood flow will be bright, and parts with poor blood flow will be dark. Many heart scans produce color images. Different colors indicate different amounts of radioactive material adsorption. 

A heart scan may be done at rest or during exercise (nuclear stress test). Stress testing gives your doctor a better understanding of how your heart works. If you can not exercise, you may be taking medicine to increase blood flow to your heart, as if you were exercising. This test is called the chemical or drug stress test. If the test is normal during exercise and rest, the coronary artery blood flow is normal. This test may show normal bloodstream at rest, but after exercise, it may reveal a defect in the blood supply going to the heart. This may be due to an obstruction in one or more coronary arteries (hearts). Coronary artery occlusion can cause a "blood flow defect" or form an area where more or less absorption of the tracer is seen. 

This test may be abnormal during exercise and rest. In this case, the tracking material will be visible in more than one area. This means that not enough blood is flowing to that part of the heart at any given time.

 Lack of a tracer often means that cells in that area have died from a previous heart attack. Using special radioactive detectors designed for this test, a heart scan can also show how your left ventricle is pumping.

Risks of heart scan

A heart scan is safe for most people. The amount of radiation is low, which your body excretes it through your kidneys within 24 to 72 hours. If you are pregnant or breast-feeding, or you suspect pregnancy, tell your doctor before having this test, as this imaging procedure may harm your baby.

Preparing for a heart scan

Tell your doctor about any medications you are taking, including Over-The-Counter (OTC) medications, herbs, and vitamins. Do not stop taking medicine until your doctor tells you to. Your doctor may ask you not to take it before the test. Your doctor may also ask you not to eat certain foods, such as caffeinated beverages, 24 hours before the test. If you have recently consumed caffeine, the test may be delayed or canceled. Fast for 4 to 6 hours before the imaging, but you can drink water during this time. Wear comfortable, loose-fitting clothes and shoes if your doctor prescribed you a nuclear scan with an exercise stress test.

The process of performing a nuclear heart scan

Physicians and nuclear medicine technicians usually perform the scan in a hospital or clinic using special equipment. The technician places small electrodes on the chest, arms, and legs. Electrodes have wires that connect to a device that records your ECG. It monitors your heart rate during the test and can record your heart rate at the same time when shooting with a nuclear camera. To check blood pressure during imaging, a cuff is wrapped around your arm that measures your blood pressure at regular intervals. The technician will usually insert an angiocatheter into your arm, which the tracker will be injected by this intravenous method. To scan at rest, you will lie on a table then a gamma camera will move around your chest, turning the tracker marks into a photo. For the nuclear stress test, you either walk on a treadmill or ride a stationary bike. Then you will lie down on the table again to shoot. If you can not exercise, you will receive intravenous medication (chemical stress) to increase blood flow to your heart, just like what happens during physical activity. These medications may include adenosine, dipyridamole (pristine), or dobutamine. This test usually takes between 2 and 2.5 hours.

After performing a nuclear heart scan

You can usually return to normal activities immediately.
Drink plenty of water for the next few days. This helps you to expel radioactive material from your body.
See your doctor to discuss test results and determine the next steps.