Each heart examination has its own specific precautions, and healthcare professionals should provide clear instructions before the examination. Generally, before the examination: Fasting may be required as instructed. Avoid exercising. Remove metal items such as watches and jewelry. If you are on long-term medication, consult your doctor to determine if you need to temporarily stop the medication. If you are pregnant, have a history of allergies, asthma, or known kidney dysfunction, consult your doctor to determine if the examination is suitable for you. Take prescribed medications as instructed by the doctor (if applicable).