Nuclear cardiology is a special type of X-ray procedure that uses very small amounts of radioactive material to diagnose heart disease. It is safe, and the amount of radiation exposure is no greater than a common chest X-ray. It is highly effective in determining the degree of blood flow to the heart muscle and in detecting the presence of arterial blockages in the heart. This test helps a doctor to determine the extent of the risk of heart disease and the best way to manage it. The entire test takes about three to four hours.