A Resource for
Nuclear Lab Professionals
 

Exercise Testing

Bruce Protocol

The Bruce Protocol is the most widely used exercise testing method.1

 

Table 1. Bruce Protocol1

Stage

Speed, mph

Incline, %

METs

Total Time, min

1

1.7

10

4.6

3

2

2.5

12

7.0

6

3

3.4

14

10.1

9

4

4.2

16

12.9

12

5

5.0

18

15.0

15

6

5.5

20

16.9

18

 

Duke Treadmill Score

The Duke Treadmill Score is used for risk stratification with treadmill testing.

 

Table 2. Duke Treadmill Score (DTS): Equation and Risk Stratification2-4

EQUATION

DTS = exercise timea – (5 x max ST deviation in mm) – (4 x treadmill angina indexb)

RISK STRATIFICATION

DTS

Risk

< –10

High (79% 4-year survival)

–10 to +4

Moderate (95% 4-year survival)

≥ +5

Low (99% 4-year survival)

a In minutes on the Bruce protocol.
b No angina during exercise = 0; nonlimiting angina = 1; angina that limited exercise = 2.3

 

Suboptimal Exercise in MPI

Exercise is the preferred method of stress for myocardial perfusion imaging, but some patients may not be able to exercise adequately for a variety of reasons.

 

For exercise to be adequate for imaging, the patient must reach at least 85% of his or her maximal predicted heart rate,5 as estimated by the following equation1:

 

220 − patient age = maximal predicted heart rate

 

Table 3. Clinical Impact of Suboptimal Exercise

Decreased testing sensitivity/false-negative results6
Need to repeat the study using pharmacologic stress7
Double radiation exposure for patients7
Scheduling disruptions for patients and labs
Delayed diagnostic information for physicians7

 

Table 4. Certain Patients May Be Less Likely to Achieve Adequate Exercise Levels7-13

DEMOGRAPHICS/PATIENT CONDITIONS

Poor physical condition7 Advanced age7
Poor motivation7  Diabetes9
Musculoskeletal/orthopedic problems7 Obesity
Peripheral vascular disease7  Hypertension7,10
Pulmonary disease7  Metabolic syndrome11
Cerebrovascular problems7  African American women12
Lower-limb amputation   Women13
Presurgical limitations8  

 

Patient Effort Level: Perceived Exertion

 

Below are 2 self-rating scales that can be used with patients to determine their levels of effort/exertion while exercising on the treadmill. (Click on the images for a printable version that can be used with your patients.)

 

Borg Rating of Perceived Exertion Scale (RPE)14

Heart rate can be approximated by multiplying the Borg RPE by a factor of 10.14 Actual heart rate can vary depending on age and physical condition.

 

Modified Rating Perceived Exertion (CR10)15

 

References

  1. Wackers FJTh, Bruni W, Zaret BL. Stress procedures. In: Wackers FJTh, Bruni W, Zaret BL. Nuclear Cardiology: The Basics. How to Set Up and Maintain a Laboratory. 2nd ed. Totowa, NJ: Humana Press; 2008:53-75.
  2. Gibbons RJ, Abrams J, Chatterjee K, et al. ACC/AHA 2002 guideline update for the management of patients with chronic stable angina: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for the Management of Patients with Chronic Stable Angina). 2002. Available at www.acc.org/clinical/guidelines/stable/stable.pdf. Accessed February 4, 2013.
  3. Gibbons RJ, Hodge DO, Berman DS, et al. Long-term outcome of patients with intermediate-risk exercise electrocardiograms who do not have myocardial perfusion defects on radionuclide imaging. Circulation. 1999;100:2140-2145.
  4. Gibbons RJ, Balady GJ, Bricker JT, et al. ACC/AHA 2002 guideline update for exercise testing: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Exercise Testing) 2002. Available at: http://circ.ahajournals.org/content/106/14/1883.full. Accessed February 4, 2013.
  5. Henzlova MJ, Cerqueira MD, Hansen CL, Taillefer R, Yao S-S. Stress protocols and tracers. J Nucl Cardiol. 2009. Available at: http://www.asnc.org/imageuploads/imagingguidelinesstressprotocols021109.pdf Accessed February 4, 2013.
  6. Iskandrian AS, Heo J, Kong B, Lyons E. Effect of exercise level on the ability of thallium-201 tomographic imaging in detecting coronary artery disease: analysis of 461 patients. J Am Coll Cardiol. 1989;14:1477-1486.
  7. Cerqueira MD. Pharmacologic stress versus maximal-exercise stress for perfusion imaging: which, when, and why? J Nucl Cardiol. 1996;3:S10-S14.
  8. Bar Harbor Invitation Meeting 2000. J Nucl Cardiol. 2001;8:224-316.
  9. Consensus development conference on the diagnosis of coronary heart disease in people with diabetes. Diabetes Care. 1998;21:1551-1559.
  10. Lim PO, MacFadyen RJ, Clarkson PBM, MacDonald TM. Impaired exercise tolerance in hypertensive patients. Ann Intern Med. 1996;124:41-55.
  11. Farrell SW, Cheng YJ, Blair SN. Prevalence of the metabolic syndrome across cardiorespiratory fitness levels in women. Obes Res. 2004;12:824-830.
  12. Roger VL, Go AS, Lloyd-Jones DM, et al. Heart disease and stroke statistics—2012 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2012;155:e2-e220.
  13. Isaac D, Walling A. Clinical evaluation of women with ischemic heart disease: diagnosis and noninvasive testing. Can J Cardiol. 2001;17(suppl D):38D-48D.
  14. Borg G. Perceived exertion as an indicator of somatic stress. Scan J Rehabil Med. 1970;2:92-98.
  15. Borg GAV. A category scale with ratio properties for intermodal and interindividual comparisons. In: Geissler H-G, Petzold P, eds. Psychophysical Judgement and the Process of Perception. Berlin: VEB Deutscher Verlag der Wissenschaften; 1982:25-34.
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