Myocardial Perfusion

Overview

The Myocardial Perfusion Nuclear Medicine Study demonstrates the distribution of blood flow and perfusion to the mycocardium at stress and rest.

Indications

  • Detection of coronary artery disease.
  • Documentation of myocardial perfusion abnormalities before and after interventional therapy.
  • Evaluating the success of Coronary Angioplasty (PTCA) or Coronary Bypass Surgery (CAB).

Study Description

When the patient arrives they are first taken to get a double port IV started (someone at the hospital usually does this). After the IV is started, the nuclear medicine technologist will meet the with the patient, explain the procedures and give them an injection of Tc-99m-Cardiolite (Sestimibi).

The patient will then wait approximately 30 minutes before they are taken for their first set of pictures, which lasts approximately 12-30 minutes. After taking the first set of pictures, the patient is taken to another part of the hospital to await the stress portion of their test.

Respiratory will get the patient when they are ready. The patient will be hooked up to an EKG, oxygen saturation monitor (if desired), and blood pressure equipment.

The doctor will come into the room and the stress test will begin.

Treadmill Stress Testing

  • A target heart rate needs to be calculated before the stress test begins.
  • The treadmill protocol (used by other facilities) is at the start of each three minute stage. The treadmill should increase in speed and grade (Bruce Protocol).
  • The goal and recommended time to inject the second dose of Tc-99m- Cardiolite (Sestimibi) is not less than 85% of the target heart rate (220 - patient's age * 85%).
  • After the second injection, the patient has to continue to exercise for at least one minute.
  • When the treadmill is finished, the patient is monitored and EKG's are taken.
  • After the monitoring is complete and the patient has recovered from the stress testing, the patient is returned to the waiting room where they will wait for a minimum of 30 minutes before taking the second set of pictures. The second set of pictures will also last approximately 30 minutes.

Adenosine/Lexiscan Stress Testing

  • Aminophylline or Theophylline needs to be on hand.
  • The patient lies on a bed (the head can be slightly raised).
  • The adenosine/lexiscan is injected and a second dose of Tc-99m-Cardiolite (Sestimibi) will be injected with the stress agent.
  • When the injection is finished, the patient is monitored and EKG's are taken. After the monitoring is complete and the patient has recovered from the stress testing, the patient is returned to the waiting foom where they will wait approximately 30 minutes before taking the second set of pictures. The second set of pictures will also last approximately 12-30 minutes.

The patient is now free to go home, eat, drink and continue daily routines.

Examination Time

  • Rest - Initially, 5-10 minutes for injections. Then patient must wait approximately 30 minutes before the first set of images can be taken. Imaging takes approximately 12-30 minutes.
  • Stress - Intially, 20-30 minutes to complete stress testing and receive second injection. Then the patient must wait approximately 30 minutes before the second set of images can be taken. Imaging takes approximately 12-30 minutes.

Patient Preparation

  • Ensure patient is not pregnant or breast-feeding
  • NPO (nothing by mouth) for 4 hours prior to exam (patient is allowed water)
  • No caffeine or caffein containing medications 24 hours prior to exam (No coffee, decaf coffee, tea, herbal tea, soft drinks, chocolate) (Note: Caffeine-free and decaffeinated beverages also contain small amounts of caffeine.)
  • No Theophylline for 48 hours prior to exam
  • No Aggrenox or Persantine for 72 hours prior to exam
  • No beta blockers for 24 hours
  • Wear comfortable clothes and shoes with no metal on the shirt
  • If the patient uses inhalers, they should bring them to the stress test.