Procedure Guideline for Equilibrium Ventriculography

Mark D. Wittry, Jack E. Juni, Henry D. Royal, Gary V. Heller and Steven C. Port Saint Louis University, St. Louis, Missouri; William Beaumont Hospital, Royal Oak, Michigan; Mallinckrodt Institute of , St. Louis, Missouri; Hartford Hospital, Hartford, Connecticut; and Cardiovascular Associates, Ltd., Milwaukee, Wisconsin

a. To distinguish ischemie from nonischemic causes. Key Words: gated blood-pool imaging;practice guideline;radionu- b. To distinguish systolic from diastolic causes. clide ventriculography; cardiac function; 3. Evaluation of cardiac function in patients undergoing J NucíMed 1997; 38:1658-1661 chemotherapy. 4. Assessment of ventricular function in patients with PART I: PURPOSE valvular stenosis and/or insufficiency. The purpose of this guideline is to assist An RVG may be used in the conditions listed above for: practitioners in recommending, performing, interpreting and (a) determining long-term prognosis, (b) assessing short- reporting the results of gated equilibrium radionuclide ventricu term risk (e.g., pre-operative evaluation) and (c) moni lography. toring the response to surgery or other therapeutic inter ventions. PART II: BACKGROUND INFORMATION AND DEFINITIONS Gated equilibrium radionuclide ventriculography (RVG) is a PART IV: PROCEDURE procedure in which the patient's blood is radiolabeled and A. Patient Preparation ECG-gated cardiac scintigraphy is obtained. Single or multiple 1. Rest measurements of left and/or right ventricular function are made. No special preparation is required for a resting RVG. Alternative terminologies for this technique include gated A fasting state is generally preferred. It is not neces cardiac blood-pool imaging, multigated acquisition (MUGA) sary to withhold any medications. The electrodes used and gated equilibrium radionuclide (RNA). for cardiac gating must be placed securely to the skin Data are collected from several hundred cardiac cycles to in order to ensure an optimal ECG signal. generate an image set of the beating heart that is presented as a 2. Exercise single, composite cardiac cycle. The method can be used to The patient should be fasting for at least 3-4 hr prior assess: (a) regional and global wall motion, (b) cardiac chamber to the study, and should be both hemodynamically size and morphology and (c) ventricular systolic and diastolic and clinically stable. Exercise stress is generally function including left and right ventricular ejection fractions. preferred. Patients who are unable to exercise for An RVG may be acquired at rest, during exercise or following noncardiac reasons may undergo pharmacologie either pharmacologie or mechanical interventions. stress. It is recommended that medications that may alter the heart rate response be withheld unless med PART III: COMMON INDICATIONS ically contraindicated or the efficacy of the medica A. Parameters obtained from RVG include the following: tion is being tested by the exercise test. 1. Global ventricular systolic function. Life support instrumentation and cardiac resuscita- 2. Regional wall motion. tive drugs must be available in the immediate vicinity 3. Ventricular volumes (qualitative or quantitative). of the stress laboratory. A physician or other person 4. Responses of above parameters to exercise or other nel trained in advanced cardiac life support (ACLS) interventions. must be immediately available during the stress and 5. Systolic and diastolic indices. recovery phases. Continuous electrocardiographic 6. volume ratios. monitoring must also be performed throughout all B. Common clinical settings in which RVG may be useful phases of the stress study. Intermittent blood pressure include: measurement and electrocardiographic tracings 1. Known or suspected (CAD). should be performed prior to, during and in the a. CAD without myocardial infarction (MI). recovery phases of the stress study. The patient should b. Remote MI. be clinically observed during and immediately fol c. Acute MI. lowing the stress test. Any abnormalities in symptom 2. Known or suspected congestive heart failure (CHF). atology, hemodynamics or the ECG should be moni tored until resolved. Received Dec. 18, 1996; accepted Jun. 17, 1997. For correspondence or reprints contact: Wendy J.M. Smith, Director of Health Care B. Information Pertinent to Performing the Procedure Policy, 1850 Samuel Morse Dr., Reston, VA 20190-5316 or via e-mail at An adequate history and cardiovascular examination [email protected]. Note: All 26 SNM-approved procedure guidelines are available on the Society's home should be obtained prior to diagnostic evaluation. Spe page. We encourage you to download these documents via the Internet at http: cific areas to be reviewed include the indication(s) for \\www.snm.org. If you would like information on the development process of this testing, medications, symptomatology, cardiac risk fac guideline or to order a compendium of all 26 procedure guidelines for $20.00, please contact Wendy J.M. Smith, Society of Nuclear Medicine at (703) 708-9000, ext. 242 or tors and prior cardiac procedures (diagnostic or therapeu via e-mail at [email protected]. tic). The patient's cardiac rhythm should be noted, as

1658 THEJOURNALOFNUCLEARMEDICINE•Vol. 38 •No. 10 •October 1997 TABLE 1 TABLE 2 Radiation Dosimetry for Adults Radiation Dosimetry for Children (5-yr-old) receivingthe largestradiation receiving dose*mGy the largest dose* "To-labeled(mCi)555-1 (rad)0.023Heart(0.085)0.020Heart(0.074)Effectivedose*mSv(rem)0.0085(0.031)0.0079(0.029) activity radiation dose* Radiopharmaceutical"To-labeledMBq/kg(mCi/kg)7-1 mGy(rad)0.062 mSv(rem)0.025 RBCs*"Tc i.V.(15-30)370-740110 5 i.v. RBCst"Te (0.2-0.4)5-10 Heart (0.093)0.023 albumin*AdministeredactivityMBqi.V.(10-20)Organ (0.23) albumin*Administered i.v. 0.054 (0.1-O.3)Organ Heart (0.085) (0.20)Effective *Per MBq (per mCi). TICRP53, page 210. *Per MBq (per mCi). *ICRP53, page 173. nCRPSS, page 210. »ICRP53,page 173.

marked heart rate variability may limit the ability to both perform and interpret the RVG. Physical limitations may tor. An appropriate ECG gating device should limit or preclude the performance of a study requiring interface with the acquisition computer. The si physical exercise. A resting 12-lead electrocardiogram multaneity of the gating device's R-wave trigger should be reviewed prior to an exercise study. and the patient's QRS complex should be verified C. Precautions prior to initiation of the study. An appropriate R-R 1. It is mandatory that the OSHA guidelines for safe interval beat acceptance window should be se handling of human blood products be followed at all lected to account for heart rate variability and times when techniques labeling autologous red blood ectopy. Systolic function determinations are less cells are used. susceptible to heart rate variability than diastolic 2. When an in vitro method is used for radiolabeling function measurements. "List" mode acquisition is autologous red blood, a fail-safe policy and procedure useful for making a composite cardiac cycle from must be in place and implemented to assure that a heterogenous population of beats. misadministration of labeled cells to the wrong pa b. Acquisition Parameters tient is prevented. A minimum of 16 frames per R-R interval are 3. Patients with potentially unstable cardiac rhythms required for an accurate assessment of ventricular (e.g., paroxysmal supraventricular or ventricular wall motion and assessment of ejection fraction. A tachycardia) or implanted devices (e.g., implantable higher framing rate (32-64 frames per R-R) is defibrillators) may require special precautions as heart rate response to exercise may be unpredictable. necessary for detailed measurement of diastolic D. filling parameters. For the adult, the usual administered activity is 555-1110 Images should be acquired such that the heart MBq (15-30 mCi) of autologous red blood cells labeled occupies approximately 50% of the usable field of with 99mTc(Table 1) using either the in vivo, modified in view. Typical acquisitions are for a total of 3-7 vitro or in vitro techniques. The usual administered million counts. Supine imaging is performed in a activity in children is 7-15 MBq/kg (0.2-0.4 mCi/kg) minimum of three views to visualize all wall with a minimum dose of 70-150 MBq (2-4 mCi) (Table segments of the left ventricle. The left anterior oblique acquisition (LAO) is obtained at 45°or an 2). The largest absorbed radiation dose to an organ is to the heart (about 0.02 mSv/MBq). 99mTc-labeled red angle which allows the best separation of the right blood cells distribute within the blood-pool with an and left ventricles (best septal or best separation estimated volume of distribution of approximately view). An anterior acquisition is obtained in a 4%-7% of body weight. The estimated biological half- straight (0°)anterior projection or at an angle approximately 45°less than the "best septal" view. life is approximately 24-30 hr. Approximately 25% of the administered dose is excreted in the urine in the first The lateral acquisition is obtained as a left cross- 24 hr. table lateral or at an angle that is approximately 45°greater than the best septal view. A 70°LAO Labeling is least consistent with the in vivo, interme diate with the modified in vitro and most consistent with acquisition may be used instead of a left cross- the in vitro method. -99m radiolabeled hu table lateral view. Left posterior oblique (LPO) or man serum albumin (HSA) is an alternative to radiola right anterior oblique (RAO) acquisitions may be beled red blood cells. of additional benefit. A slant-hole collimator may E. Image Acquisition be used for angulation in the caudal-cephalic plane 1. Rest study to help separate the ventricles from the atria. a. Instrumentation Stress Study Acquisition is performed by a a. Instrumentation interfaced to a dedicated computer. Images are Referto IV.E.l.a. acquired with either a low-energy, all-purpose A high sensitivity or LEAP collimator is pre (LEAP) or high-resolution, parallel-hole collima- ferred for the stress equilibrium study.

PROCEDUREGUIDELINEFORRVG •Wittry et al. 1659 b. Acquisition Parameters matic display of each view. Abnormalities of contrac Referto IV.E.l.b. tion should be described using the conventional terms 16 frames per R-R interval are sufficient for of hypokinesia, akinesia and dyskinesia. Systematic assessment of ventricular wall motion and left reporting may be aided by standardized recording ventricular ejection fraction (LVEF). Images may forms. Parametric images such as phase and ampli be acquired on a bicycle ergometer in either a tude images may be useful in evaluating regional supine, semiupright or upright position using the variations in the timing and magnitude of contraction, best septal view, as previously described, or other identifying valve planes and in the identification of views, as appropriate, to visualize a particular conduction abnormalities. The pattern of left ventric region of interest. The most accurate determination ular diastolic function may be qualitatively evaluated of the LVEF is obtained in the best septal view. and supported by quantitative measurements. Right Images may be acquired at multiple levels of ventricular systolic function may be approximated by exercise. A 2-3 min acquisition may be attained at calculation of right ventricular ejection fraction, how each new level of exercise once a stable heart rate ever, more accurate determination may require a is attained (usually beginning after one minute of different technique such as first pass radionuclide exercise at the new level). The last stage of angiography. exercise may be extended to increase image statis 4. Cardiac Rhythm tics, but workload should not be decreased. A A single channel rhythm strip should be reviewed postexercise RVG is desirable to assess postexer when the scintigraphic data is interpreted. cise recovery. Pharmacologie stress with inotropic agents or 5. Stress Images vasodilators and atrial or ventricular pacing are The stress or intervention study should be displayed other less common alternatives to exercise testing. side by side with the resting study in cinematic mode. F. Interventions Changes in chamber sizes, regional wall motion and None global ejection fraction of both ventricles should be G. Processing assessed qualitatively and reported. The cine loop should be reviewed for adequacy of 6. Comparison to Previous Studies counting statistics, appropriate ECO gating, adequacy of Results should be compared to any previous studies radiopharmaceutical labeling and positioning of the by direct comparison of the cinematic displays of the heart. A subjective visual assessment of left ventricular two studies, whenever possible. Discrepancies should systolic function should be performed prior to calculation be resolved by reprocessing when necessary. of LVEF. Regions of interest (ROIs) should be created, I. Quality Control either manually by the operator or automatically by the Please refer to the Society of Nuclear Medicine Proce computer, so that all activity from the left ventricle is dure Guideline for General Imaging. encompassed by the ROI. The ROI used for background J. Sources of Error correction should be free of activity from the spleen or 1. RBC Labeling descending aorta. Other ventricular systolic and diastolic Certain medications (e.g., heparin) and disease pro parameters may be generated. Discrepancies between the cesses (e.g., chronic renal failure) will decrease label calculated LVEF and qualitative left ventricular systolic ing efficiency and reduce the target-to-background function should be resolved by reprocessing when nec ratio. essary. Ventricular volumes may be calculated using 2. Patient Positioning either count-based or geometric methods. Calculation of The ejection fraction may be inaccurately calculated the stroke volume ratio may be helpful in patients by inadequate separation of the left ventricle from suspected of valvular disease. Parametric images (e.g., other cardiac structures. phase/amplitude images) may be generated. 3. Gating Errors H. Interpretation/Reporting A poor ECG signal or one in which complexes other 1. Image Quality than the QRS complex are dominant may result in The interpreting physician should first assess the spurious gating and data that is not interpretable. Care overall quality of the image set, especially in regard to the adequacy of radiolabeling (target-to-background should be taken to ensure that the QRS complex is the triggering signal. ratio), ECG gating and appropriateness of views 4. Heart Rate Variability obtained. 2. Cardiac Morphology Significant heart rate variability may compromise the The morphology, orientation and sizes of the cardiac determination of diastolic filling indices. chambers, and great vessels should be subjectively 5. Image Statistics evaluated and reported. The thickness of the pericar Inadequate counts/frame may compromise image in dia! silhouette and the ventricular wall may also be terpretation as well as decrease the statistical reliabil subjectively evaluated and reported. When measured, ity of quantitative measurements. absolute ventricular volumes may also be included. 6. Processing Errors 3. Systolic Ventricular Function Inclusion of non-ventricular activity or exclusion of Global left ventricular function should be assessed ventricular activity from ventricular ROIs may cause qualitatively and compared to the calculated ejection underestimation or overestimation of the ejection fraction. Discrepancies should be resolved by repro fraction. Inclusion of structures such as the spleen or cessing when necessary. All left ventricular segments the descending aorta in the background ROI may alter should be assessed for regional function using cine the left ventricular ejection fraction.

1660 THI:JOURNALOFNUCLEARMEDICINE•Vol. 38 •No. 10 •October 1997 PART V: DISCLAIMER in medically treated patients The Society of Nuclear Medicine has written and approved with coronary artery disease: a comparison with clinical guidelines to promote the cost-effective use of high quality and catheterization variables. Circulation 1990;82:1705- nuclear medicine procedures. These generic recommendations 1717. cannot be applied to all patients in all practice settings. The 12. Links JM, Becker LC, Shindledecker JG, et al. Measure guidelines should not be deemed inclusive of all proper proce ment of absolute left ventricular volume from gated dures or exclusive of other procedures reasonably directed to blood-pool studies. Circulation 1982;65:82-91. obtaining the same results. The spectrum of patients seen in a 13. Mahmarian JJ, Moye L, Verani MS, et al. Criteria for the specialized practice setting may be quite different than the accurate interpretation of changes in the left ventricular spectrum of patients seen in a more general practice setting. The ejection fraction and cardiac volumes as assessed by rest appropriateness of a procedure will depend in part on the and exercise gated radionuclide angiography. J Am Coll prevalence of disease in the patient population. In addition, the Cardiol 1991:18:112-119. resources available to care for patients may vary greatly from 14. Massardo T, Gal RA, Grenier RP, et al. Left ventricular one medical facility to another. For these reasons, guidelines volume calculation using a count-based ratio method cannot be rigidly applied. applied to multigated radionuclide angiography. J Nucí Advances in medicine occur at a rapid rate. The date of a Med 1990:31:450-456. guideline should always be considered in determining its 15. Miller TR, Goldman KJ, Sampathkumaran KS, et al. current applicability. Analysis of cardiac diastolic dysfunction: application in coronary artery disease. J NucíMed 1983;24:2-7. PART VI: ISSUES REQUIRING FURTHER 16. Palmeri ST, Bonow RO, Meyers CE, et al. Prospective CLARIFICATION evaluation of doxorubicin cardiotoxicity by rest and None exercise radionuclide angiography. Am J Cardiol 1986; 58:607-613. PART VII. CONCISE BIBLIOGRAPHY 17. Polak JR, Kemper A, Bianco JA, et al. Resting early 1. Alexander J, Daniak N, Berger HJ, et al. Serial assess peak diastolic filling rate: a sensitive index of myocardial ment of doxorubicin cardiotoxicity with quantitative dysfunction in patients with coronary artery disease. radionuclide angiocardiography. N Engl J Med 1979; J NucíMed 1982:23:471-478. 300:278-283. 18. Rocco TP, Dilsizian V, Fischman AJ, et al. Evaluation of 2. Bacharach SL, Bonow RO, Green MV. Comparison of ventricular function in patients with coronary artery fixed and variable temporal resolution methods for cre disease. J NucíMed 1989;30:1149-1165. ating gated cardiac blood-pool image sequences. J Nucí 19. Spirito P, Marón BJ, Bonow RO. Noninvasive assess Med 1990;31:38-42. ment of left ventricular diastolic function: comparative 3. Bacharach SL, Green MV, Borer JS, et al. Left ventric analysis of Doppler echocardiographic ad radionuclide ular peak ejection rate, peak filling rate and ejection techniques. J Am Coll Cardiol 1986;7:518-526. fraction: frame rate requirements at rest and exercise. 20. Stewart RAH, McKenna WJ. Assessment of diastolic JNitcl Med 1979;20:189-193. filling indexes obtained by radionuclide ventriculogra- 4. Bonow RO. Radionuclide angiography for risk stratifi phy. Am J Cardiol 1990:65:226-230. cation of patients with coronary artery disease [Editori 21. Upton MT, Rerych SK, Newman GÈ, et al. The repro- al]. Am J Cardiol 1993;72:735-739. ducibility of radionuclide angiographie measurements of 5. Bonow RO, Kent KM, Rosing DR, et al. Exercise- left ventricular function in normal subjects at rest and induced in mildly symptomatic patients with during exercise. Circulation 1980;62:126-132. coronary artery disease and preserved left ventricular 22. U.S. Department of Health and Human Services, Public function: identification of subgroups at risk of death Health Service. Clinical Practice Guideline Number 11. during medical therapy. N Engl J Med 1984;311:1339- Heart failure: evaluation and care of patients with 1345. left-ventricular systolic dysfunction. AHCPR Publication 6. Bonow RO, Picone AL, Mclntosh CL, et al. Survival and No. 94-0612, 1994. functional results after valve replacement for aortic régur gitation from 1976 to 1983: impact of preoperative left PART VIII: LAST HOUSE OF DELEGATES APPROVAL ventricular function. Circulation 1985;72:1244-1256. DATE 7. Bonow RO, Rosing DR, Kent KM, et al. Timing of June 11, 1995 operation for chronic aortic régurgitation.Am J Cardiol 1982;50:325-336. PART IX: NEXT ANTICIPATED APPROVAL DATE 8. Breisblatt WM, Vita NA, Armuchestegui M, et al. 1997 Usefulness of serial radionuclide monitoring during graded nitroglycerin infusion for unstable angina pecto- ACKNOWLEDGMENTS ris for determining left ventricular function and individ Wendy Smith, MPH, Director of Health Care Policy, Society ual therapeutic dose. Am J Cardiol 1988;61:685-690. of Nuclear Medicine, for project coordination, data collection 9. Dilsizian V, Rocco TP, Bonow RO, et al. Cardiac and editing; members of the Guideline Development Subcom blood-pool imaging II: applications in noncoronary heart mittee Jeffrey Dobkin, MD, Howard Dworkin, MD, and David disease. J NucíMed 1990;31:10-22. Price, MD; other SNM members Barbara Croft, PhD, Carol 10. Juni JE, Chen CC. Effects of gating modes on the Marcus, MD, PhD, H. William Strauss, MD; and members of analysis of left ventricular function in the presence of the SNM Cardiovascular Council Board of Directors who heart rate variation. J NucíMed 1988;29:1272-1278. contributed their time and expertise to the development of this 11. Lee KL, Pryor DP, Peiper KS, et al. Prognostic value of information.

PROCEDUREGUIDELINEFORRVG •Wittry et al. 1661