Stress Tests

General:

1.        Hold any nitroglycerin product for at last 1 hour prior any stress test

2.        Assess:

1. Double product:  HR X SBP
2. Precense of fixed (infarct) vs. reversible (ischemic) defect
3. Segments of wall involved
4. Wall motion abnormalities

3.    Want to achieve 85% maximal predicted HR for a diagnostic test

1.       Stress Treadmill or EKG

1. Cost $300
2. Evaluates:

1.        EKG changes indicating ischemia

2.        METS (>4 indicates good exercise tolerance and predicts better cardiac outcomes)

2.       Dubutamine Echo

1. Cost $1100  (regular TTE $800)
2. Contraindicated if on bb.  Hold am dose.
3. Poor results if large or large chest

1. Can eat a light meal prior test
2. Evaluates:

1.        EF % (nl 55-70)

2.        LV size

3.        Wall thickness (nl < 45)

4.        Valvular function

5.        Diastolic dysfunction

6.        CAD

7.        Wall motion indicating ischemia

4. Sensitivity:  85-87%
5. Specificity 89%

3.       Nuclear MIBI

1. Cost $3200
2. Dipyridamole/adenosine best test if LBBB or pacemaker or on a bb 
3. Contraindicated if true asthma or severe reactive airway
4. Hold caffeine or theophylline at least 12 hrs prior test
5. Can cause chest tightness
6. Dipyridamole can increase CO 3-5 times normal
7. Evaluates:

1.        Ischemic burden

2.        EF% (~7% less than TTE)

8. Sensitivity 89%
9. Specificity 85%