EHR519 Lecture Notes - Lecture 12: Coronary Artery Disease, Revascularization, Sensitivity And Specificity
1. Week 12 – Clinical Interpretation of Cardiovascular
and Pulmonary Diseases
Diagnostic Exercise Testing
Patients with a high probability of disease (e.g., typical angina, prior coronary revascularization, myocardial
infarction) are tested to assess residual myocardial ischemia, to assess threatening ventricular arrhythmias, and for
health prognosis rather than for diagnostic purposes
Accuracy if Diagnostic Tests
Positive test
Patient evaluated has an abnormality that was identified by the test.
Negative test
Did not find the abnormality
Any clinical test, even if considered the “gold standard,” will not always correctly identify whether a
person has or does not have an abnormality.
False-positive result
Test result is positive, but the patient is later found to not have the abnormality.
False-negative result
Test result is negative, but the patient is later found to have the abnormality.
True-positive and true-negative
Tests that accurately assess a patient as positive or negative for an abnormality
Sensitivity
How often the test uncovers an abnormality or disease in a population with the abnormality or
disease
Specificity
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How often the test is negative or normal in a population without the abnormality or disease
Success of any diagnostic test depends on
Technical performance of the test
Appropriateness of the test for the person being evaluated
Interpretation or clinical judgment of the clinician who evaluates the results
Predictive value
Ability of a test to accurately determine the presence or absence of an abnormality or disease in
a single person
Relies on the test sensitivity and specificity and the prevalence of disease in the population being
tested
Positive predictive value
Probability of disease being present in a person with a positive test
Negative predictive value
Probability of disease being absent in a person with a negative test
It is important that the proper population, techniques, and interpretation be applied to any clinical test to
enhance the predictive value. It is this criterion on which studies in the literature are evaluated and
recommendations are made for diagnostic testing.
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How to Decide Which Diagnostic Test To Select
The decision to perform a graded exercise test with
electrocardiography should be made based on several
criteria:
Pretest likelihood that the patient has CAD
Can patient adequately exercise to symptom-
limited maximum?
Will the ECG be interpretable at peak exercise for
possible ischemia
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Document Summary
Week 12 clinical interpretation of cardiovascular and pulmonary diseases. Patients with a high probability of disease (e. g. , typical angina, prior coronary revascularization, myocardial infarction) are tested to assess residual myocardial ischemia, to assess threatening ventricular arrhythmias, and for health prognosis rather than for diagnostic purposes. Patient evaluated has an abnormality that was identified by the test. Any clinical test, even if considered the gold standard, will not always correctly identify whether a person has or does not have an abnormality. Test result is positive, but the patient is later found to not have the abnormality. Test result is negative, but the patient is later found to have the abnormality. Tests that accurately assess a patient as positive or negative for an abnormality. How often the test uncovers an abnormality or disease in a population with the abnormality or disease. How often the test is negative or normal in a population without the abnormality or disease.
