Exercise Testing

Bruce Protocol
Duke Treadmill Score
Suboptimal Exercise in MPI
Patient Effort Level: Perceived Exertion
References

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

Click on the image for a printable version

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

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. Totowa, NJ: Humana Press; 2004:43-59.
Gibbons RJ, Chatterjee K, Daley J, et al. ACC/AHA/ACP-ASIM guidelines for the management of patients with chronic stable angina: executive summary and recommendations: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Management of Patients with Chronic Stable Angina). Circulation. 1999;99:2829-2848.
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.
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://www.acc.org/qualityandscience/clinical/guidelines/exercise/exercise_clean.pdf. Accessed July 24, 2009.
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 July 24, 2009.
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.
Cerqueira MD. Pharmacologic stress versus maximal-exercise stress for perfusion imaging: which, when, and why? J Nucl Cardiol. 1996;3:S10-S14.
Bar Harbor Invitation Meeting 2000. J Nucl Cardiol. 2001;8:224-316.
Consensus development conference on the diagnosis of coronary heart disease in people with diabetes. Diabetes Care. 1998;21:1551-1559.
Lim PO, MacFadyen RJ, Clarkson PBM, MacDonald TM. Impaired exercise tolerance in hypertensive patients. Ann Intern Med. 1996;124:41-55.
Farrell SW, Cheng YJ, Blair SN. Prevalence of the metabolic syndrome across cardiorespiratory fitness levels in women. Obes Res. 2004;12:824-830.
Rosamond W, Flegal K, Friday G, et al. Heart disease and stroke statistics—2007 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2007;115:e69-e171.
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.
Borg G. Perceived exertion as an indicator of somatic stress. Scan J Rehabil Med. 1970;2:92-98.
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.