Radionuclide angiography + +

Coronary Angiography-YouTube Video

Radionuclide angiography

Purpose

MUGA is typically ordered for the following patients:

• With known or suspected coronary artery disease, to diagnose the disease and predict outcomes
• With lesions in their heart valves
• With congestive heart failure
• Who have undergone percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery, or medical therapy, to assess the efficacy of the treatment
• With low cardiac output after open-heart surgery
• Who are undergoing cardiotoxic drug agents such as in chemotherapy e.g., with doxorubicin or immunotherapy (herceptin)
• Who have had a cardiac transplant

• Coronary angiography procedure-You Tube

  Procedure

  At a high level, the MUGA test involves the introduction of a radioactive marker into the bloodstream of the patient. The patient is subsequently scanned to determine the circulation dynamics of the marker, and hence the blood.
  The introduction of the radioactive marker can either take place in vivo or in vitro. In the in vivo method, stannous (tin) ions are injected into the patient's bloodstream. A subsequent intravenous injection of the radioactive substance, technetium-99m-pertechnetate, labels the red blood cells in vivo. With an administered activity of about 800 MBq, the effective radiation dose is about 8 mSv to 12 mSv. In thein vitro method, some of the patient's blood is drawn and the stannous ions (in the form of stannous chloride) are injected into the drawn blood. The technetium is subsequently added to the mixture as in the in vivo method. In both cases, the stannous chloride reduces the technetium ion and prevents it from leaking out of the red blood cells during the procedure.
  The patient is placed under a gamma camera, which detects the low-level 140keV gamma radiation being given off by technetium-99m. As the gamma camera images are acquired, the patient's heart beat is used to 'gate' the acquisition. The final result is a series of images of the heart (usually sixteen), one at each stage of the cardiac cycle.
  Depending on the objectives of the test, the doctor may decide to perform either a resting or a stress MUGA. During the resting MUGA, the patient lies stationary, whereas during a stress MUGA, the patient is asked to exercise during the scan. The stress MUGA measures the heart performance during exercise and is usually performed to assess the impact of a suspected coronary artery disease. In some rare cases, a nitroglycerin MUGA may be performed, where nitroglycerin (a vasodilator) is administered prior to the scan.
  The resulting images show that the volumetrically derived blood pools in the chambers of the heart and timed images may be computationally interpreted to calculate the ejection fraction and injection fraction of the heart. This nuclear medicine scan yields an accurate, inexpensive and easily reproducible means of measuring and monitoring the ejection and injection fractions of the ventricles, which are one of many of the important clinical metrics in assessing global heart performance.

  External links

  • Radionuclide+Angiography at the US National Library of Medicine Medical Subject Headings (MeSH)
  • YouTube - Angiography

  • • ACC/AHA Practice Guidelines

    ACC/AHA Guidelines for Coronary Angiography: Executive Summary and Recommendations

    A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Coronary Angiography) Developed in collaboration with the Society for Cardiac Angiography and Interventions

    Figure 1.

    

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    Nomogram of prognostic relations embodied in the Duke Treadmill Score. Determination of prognosis proceeds in 5 steps: 1. The observed amount of exercise-induced ST-segment deviation (the largest elevation or depression after resting changes have been subtracted) is marked on the line for ST-segment deviation during exercise. 2. The observed degree of angina during exercise is marked on the line for angina. 3. The marks for ST-segment deviation and degree of angina are connected with a straight edge. The point where this line intersects the ischemia reading line is noted. 4. The total number of minutes of exercise in treadmill testing according to the Bruce protocol (or the equivalent in multiples of resting oxygen consumption [METs] from an alternative protocol) is marked on the exercise-duration line. 5. The mark for ischemia is connected with that for exercise duration. The point at which this line intersects the line for prognosis indicates the 5-year survival rate and average annual mortality for patients with these characteristics. Patients with <1 mm of exercise-induced ST-segment depression should be counted as having 0 mm. Angina during exercise refers to typical effort angina or an equivalent exercise-induced symptom that represents the patient’s presenting complaint. This nomogram applies to patients with known or suspected CAD, without prior revascularization or recent MI, who undergo exercise testing before coronary angiography. Modified with permission from Mark DB, Shaw L, Harrell FE Jr, et al. Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease. N Engl J Med. 1991;325:849–853. © 1991 Massachusetts Medical Society. All rights reserved.

    

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    Figure 2.

    Clinical context for noninvasive and invasive diagnostic testing of patients with known or suspected ischemic heart disease. *ECG interpretable unless preexcitation, electronically paced rhythm, left BBB, or resting ST-segment depression >1 mm. See text for discussion of use of digoxin, left ventricular hypertrophy, and ST-segment depression <1 mm. **For example, high risk if Duke treadmill score predicts average annual mortality >3%. Modified from Gibbons RJ, Balady GJ, Beasley JW, et al. ACC/AHA guidelines for exercise testing: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Exercise Testing). J Am Coll Cardiol.1997;30:260–311.

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    Table 1.

    Noninvasive Test Results Predicting High Risk¹ for Adverse Outcome