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

  1. Sensitivity:  85-87%
  2. 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)

  1. Sensitivity 89%
  2. Specificity 85%