Nuclear Cardiac Stress Imaging In Atlanta
In addition to exercise stress testing, nuclear stress testing can be used to evaluate a patient for the presence of coronary artery disease. Generally, nuclear stress testing is more accurate than regular exercise stress testing. In addition to walking on a treadmill, isotopes such as thallium, Cardiolite or Myoview are given to the patient intravenously. These agents are taken up by the heart muscle through its own dedicated arteries, enabling imaging of blood supply to the heart tissue. After the isotope is given, a blood-flow picture of the heart is obtained before the heart is stressed. Another isotope is injected while the heart is stressed and a second blood-flow picture is obtained. If there is a significant blockage in an artery, the territory of heart muscle supplied by that vessel will show reduced uptake of the isotope. This difference in blood flow allows the cardiologist to determine the presence and severity of coronary artery disease.
For patients who are unable to exercise, a chemical stress test is performed. Agents such as adenosine, persantine, and dobutamine are used to chemically stress the heart. Patients are instructed not to eat or drink anything for several hours prior to the test. They are also instructed to avoid caffeine products for at least 24 hours prior to the test to improve accuracy. Similar to exercise nuclear stress testing, isotopes are injected and images are obtained at rest and with stress. Comparisons are made between the two sets of images to determine to presence and degree of coronary artery disease. These tests are very safe and serious complications are very rare. Pregnant patients cannot receive nuclear stress testing. The entire procedure takes 2 to 3 hours to allow for adequate heart imaging.