3. Probability
Gibons at al, Progr Cardiol 1983;12:67
Positive Predictive
Value
Probability of a subject
with a positive test,
actually having disease
Depends upon
Sensitivity
Specificity
Population prevalence
or pretest likelihood
4. Pretest Probability
Age Gender Typical
Angina
Atypical
Angina
Nonanginal
CP
Asymptoma
tic
30-39 Men Intermediate Intermediate Low Very Low
40-49 High Intermediate Intermediate Low
50-59 High Intermediate Intermediate Low
60-69 High Intermediate Intermediate Low
30-39 Women Intermediate Very Low Very Low Very Low
40-49 Intermediate Low Very Low Very Low
50-59 Intermediate Intermediate Low Very Low
60-69 High Intermediate Intermediate Low
Diamond et al, NEJM 1979;300:1350
5. ACC/AHA 2002 ETT Indication
Class I (Indicated)
• Intermediate prob
CAD
• including RBBB,
<1mm resting ST
depression
Class III (Not indicated)
• Pre-excitation
• V-paced
• >1mm resting ST dep
• LBBB
• Diagnosis for pt w/
established CAD
MI or death 1 per 2500
6. Contraindications to ETT
• Acute myocardial infarction (<2 days)
• Unstable angina with recent rest pain
• Untreated life-threatening cardiac arrhythmias
• Advanced atrioventricular block
• Acute myocarditis or pericarditis
• Critical aortic stenosis or severe IHSS
• Uncontrolled hypertension
• Acute systemic illness (PE, dissection, anemia,
thyroid, fever, etc.)
7. Exercise Treadmill Testing- Protocols
Standard Bruce Protocol
Stage Min MPH Grade METS
I 03:00 1.7 10% 5
II 03:00 2.5 12% 7
III 03:00 3.4 14% 10
IV 03:00 4.2 16% 13.5
V 03:00 5.0 18% 16+
*3 minute stages
Variations
Modified Bruce Protocol
2 warm-up stages
Naughton Protocol
fixed speed
Submaximal ETT
Not to exceed 5 METS
Not to exceed 70%
MPHR
8. Diagnosis of Ischemia
Positive test
– 1mm horizontal or
down sloping ST
segment depression
0.06-0.08msec after
the j-point
(5% w/ CAD meet
criteria in recovery
alone)
– Lateral leads (V4-V6)
Up sloping
Horizontal
Down sloping
Adequate stress: 85% max predicted HR (220-age)
9. Decreased Specificity
• LVH with repolarization abnormalities
– Decreased specificity with no change in sensitivity
• Resting ST depression > 1mm
• LBBB
• RBBB (diagnostic accuracy preserved in V5, V6, II, AVF
• Digoxin
– ST depression in 25-40% of healthy subjects
– 2 weeks required washout
10. Non-coronary Causes of ST
segment depression
• Severe aortic stenosis
• Severe hypertension
• Cardiomyopathy
• Anemia
• Hypokalemia
• Severe hypoxia
• Digitalis use
• Sudden excessive
exercise
• Glucose load
• Left ventricular
hypertrophy
• Hyperventilation
• Mitral valve prolapse
• Intraventricular
conduction defect
• Preexcitation syndrome
• Severe volume overload
• Supraventricular
tachyarrhythmias
11.
12. Thompson CA, et al. JACC 2000; 36:2140-5. Lauer MS, et al. Circulation 1996;93:1520-6
14. Exercise Capacity
MET= 02 uptake of 70kg
man at rest for 1 min
=3.5ml O2/kg/min
Exercise capacity is
one of the strongest
prognostic markers
Encompasses many
different factors
Each 1 MET increase =
12% increased
survival
Stanford database of 6000 men
>13 >11
Ref
<10 <8
Myers et al, NEJM 2002;346:793
15. ETT in asymptomatic pts
Class I
• None.
Class IIa
• Evaluation of asymptomatic persons with diabetes mellitus who plan to start
vigorous exercise (see page 39). (Level of Evidence: C)
Class IIb
• Evaluation of persons with multiple risk factors as a guide to risk-reduction therapy.*
• Evaluation of asymptomatic men older than 45 years and women older than 55
years:
– Who plan to start vigorous exercise (especially if sedentary) or
– Who are involved in occupations in which impairment might impact public safety or
– Who are at high risk for CAD due to other diseases (e.g., peripheral vascular disease and
chronic renal failure)
Class III
• Routine screening of asymptomatic men or women.
19. Vasodilators
• Dipyridamole
– Increases adenosine levels
– 50% with side effects, last 15-25 minutes
• Adenosine
– Coronary vasodilation via A2A receptor
– 140mcg/kg/min x 6min
– 80% with side effects: flushing 40%, AV block
(7.6%), hypotension (5%), <10sec ½ life
– CP non-specific
– 1mmST depression 5-7%>CAD
• Regadenoson
– A2A agonist with lower affinity for receptors >
side effects
– Side effets of SOB, headache, flushing, last 15-
30 min
– Single 5ml injection
Contra-indications
• AV block (2nd or 3rd)
•Bronchospasm
•Methyl xanthines
•ACS
20. Myocardial Perfusion Testing
(Nuclear: SPECT)
Protocol (Dual Isotope)
• Resting images after Thallium-201
injection
• Stress, with Technetium-99 injected at
peak exercise (Cardiolite/Myoview)
• Post-stress images (with gated SPECT)
21. → Revasc better
Hachamovitch R, Hayes SW, Friedman JD, Cohen I, Berman DS. Circulation 2003;107:2900-6