b. Suggestive
1.Horizontal or downsloping ST segment
depression between 0.5 mm and 1 mm at 60 s
past the J point- ST elevation b/w 0.5–1.0 mm
3.Upsloping ST segment depression that is
greater than 0.7 mm but less than 1.5 mm at
80 ms past J point - Exercise-induced hypotension
- Chest pain occurring with exercise typical of
angina - Frequent, high grade, ventricular ectopy
- A new third heart sound or murmur at peak
exercise - Abnormal 1-min HRR or 3-min systolic BP
response - ST-segment depression in recovery only
- Normalization of abnormal ST-segments/
T- wave inversion
c. Negative - Above criteria not met and the patient exercised
to at least 85% of predicted HRmax
d. Inconclusive - The patient does not reach 85% of maximum
predicted HR and there is no evidence of
ischemia based on the above criteria. (Be sure
the patient is not on B-Blockers or has
chronotropic incompetence.)
CLINICAL DECISION MAKING
- Physicians can use the results of the exercise test to
guide them in the management of their patients. This
approach should include a probability statement of
CAD and a prediction of severity of CAD, prognosis
of the likelihood of future adverse events in a patient
based on the exercise treadmill score (ETS), and exer-
cise prescription.
PROBABILITY OF CAD
- The exercise test has a role in the diagnosis of CAD
with an overall 75% sensitivity and 80% specificity.
The predictive value, however, depends on the preva-
lence of CAD in the population tested. It is therefore
imperative to determine a pretest probability of CAD
in a patient, and then use the results of the treadmill to
determine a new posttest likelihood. Exercise stress
testing has the greatest value in those individuals who
have a pretest probability between 20 and 80%.
Diamond and Forrester have created tables to predict
the pretest/posttest likelihood of disease based on age,
sex, and clinical symptoms (Diamond and Forrester,
1979 ). Two examples serve to illustrate this point:
a. A 40-year old male with atypical angina has a
pretest probability of about 35%. If he has between
1 and 2 mm of ST depression on EST, his posttest
probability of CAD becomes nearly 70%, a much
more significant risk elucidated by EST.
b. A 40-year old female with atypical angina has a
pretest probability of less than 10%. If she has
between 1 and 2 mm of ST depression, her posttest
probability of CAD still is less than 20%, and little
is gained from the EST.PREDICTION OF SEVERITY OF CAD- A suggestive or positive written report may be used to
further manage patients by predicting the severity of
CAD. Upsloping, horizontal, and downsloping ST
depression correlate respectively with a worsening
extent of CAD. The following are important exercise
test predictors of severe CAD (Goldschlager, Selzer,
and Cohn, 1976 ):
a. ST depression, >2.5 mm
b. ST depression beginning at low workload, <5 METS
c. Downsloping configuration (99% predictive of
CAD) or ST elevation
d. Prolonged ST depression lasting >8 min into rest
e. Global ST depression
f. Serious dysrhythmias at low HR (<130 bpm)
g. U wave inversion
h. Low workload ability, <5 METs
i. Exercise induced hypotension
j. Chronotropic incompetence
k. Anginal symptoms - ST depression only at high workloads (HR >160 bpm
or changes only after Stage IV—Bruce protocol at
12 min) correlates with a low mortality and good prog-
nosis in patients. In fact, the ability to exercise
13 METs has a good prognosis regardless of the EKG
changes. Many cardiologists recommend repeating the
exercise test in 6 months without further workup in
these patients (Goldschlager, Selzer, and Cohn, 1976).
EXERCISE TREADMILL SCORE- This tool supports the above concepts by assigning a
score to determine prognosis (Mark et al, 1987; 1991):
Treadmill score =Exercise duration (min) − 5 ×ST
deviation (mm) − 4 ×treadmill angina index. (TM
angina index =0 if no exercise angina, 1 for exercise
angina, and 2 for exercise-limiting angina)124 SECTION 2 • EVALUATION OF THE INJURED ATHLETE