0

The full content of Annals is available to subscribers

Subscribe/Learn More  >
Articles |

The Electrocardiographic Exercise Test in a Population with Reduced Workup Bias: Diagnostic Performance, Computerized Interpretation, and Multivariable Prediction

Victor F. Froelicher, MD; Kenneth G. Lehmann, MD; Ronald Thomas, PhD; Steven Goldman, MD; Douglas Morrison, MD; Robert Edson, MS; Philip Lavori, PhD; Jonathan Myers, PhD; Charles Dennis, MD; Ralph Shabetai, MD; Dat Do, BA; Jeffrey Froning, MS, The Veterans Affairs Cooperative Study in Health Services #016 (QUEXTA) Study Group*
[+] Article and Author Information

Copyright ©2004 by the American College of Physicians


Ann Intern Med. 1998;128(12_Part_1):965-974. doi:10.7326/0003-4819-128-12_Part_1-199806150-00001
Text Size: A A A

Background: Empirical scores, computerized ST-segment measurements, and equations have been proposed as tools for improving the diagnostic performance of the exercise test.

Objective: To compare the diagnostic utility of these scores, measurements, and equations with that of visual ST-segment measurements in patients with reduced workup bias.

Design: Prospective analysis.

Setting: 12 university-affiliated Veterans Affairs Medical Centers.

Patients: 814 consecutive patients who presented with angina pectoris and agreed to undergo both exercise testing and coronary angiography.

Measurements: Digital electrocardiographic recorders and angiographic calipers were used for testing at each site, and test results were sent to core laboratories.

Results: Although 25% of patients had previously had testing, workup bias was reduced, as shown by comparison with a pilot study group. This reduction resulted in a sensitivity of 45% and a specificity of 85% for visual analysis. Computerized measurements and visual analysis had similar diagnostic power. Equations incorporating nonelectrocardiographic variables and either visual or computerized ST-segment measurement had similar discrimination and were superior to single ST-segment measurements. These equations correctly classified 5 more patients of every 100 tested (areas under the receiver-operating characteristic curve, 0.80 for equations and 0.68 for visual analysis; P < 0.001) in this population with a 50% prevalence of disease.

Conclusions: Standard exercise tests had lower sensitivity but higher specificity in this population with reduced work-up bias than in previous studies. Computerized ST-segment measurements were similar to visual ST-segment measurements made by cardiologists. Considering more than ST-segment measurements can enhance the diagnostic power of the exercise test.

*For members of the Veterans Affairs Cooperative Study in Health Services #016 (QUEXTA) Study Group, see Appendix 2.

Figures

Grahic Jump Location
Figure 1.
Receiver-operating characteristic curves comparing the diagnostic capacity of standard visual ST-segment analysis with that of the major logistic regression equations.Table 3Table 4

The vertical line is at the specificity obtained with 1 mm of visual ST-segment depression (85%). The Equation from step 4 ( ) , that included clinical, hemodynamic, visual ST-segment, and computerized measurements is similar to the Equation fromstep 3b, and both equations have better discrimination than single electrocardiographic measurements do.

Grahic Jump Location
Grahic Jump Location
Figure 2.
Receiver-operating characteristic curves comparing the diagnostic capacity of standard visual ST-segment analysis with that of several computerized measurements.

The computer measurements are similar but not superior to visual analysis. MAX EX = maximal exercise; STO = beginning of ST segment; ST60 = ST amplitude 60 milliseconds after QRS end.

Grahic Jump Location

Tables

References

Letters

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Comments

Submit a Comment
Submit a Comment

Summary for Patients

Clinical Slide Sets

Terms of Use

The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.

Toolkit

Buy Now

to gain full access to the content and tools.

Want to Subscribe?

Learn more about subscription options

Advertisement
Related Articles
Related Point of Care
Topic Collections
PubMed Articles
Forgot your password?
Enter your username and email address. We'll send you a reminder to the email address on record.
(Required)
(Required)