Stress Testing

A. Indications

  1. Complaints of dyspnea on exertion (ischemia due to coronary artery disease)
  2. Determine ventilatory/cardiac limitations to work
  3. Determine maximum workloads for developing an exercise plan or adjusting daily activities
  4. For disability purposes

B.   Contraindications

  1. PaO2 less than 45 mmHg on room air
  2. PaCO2 greater than 70 mmHg
  3. FEV1 less than 30% predicted
  4. Recent MI 
  5. Unstable angina
  6. 2nd or 3rd degree heart block
  7. Rapid ventricular/atrial arrhythmias
  8. Congestive heart failure (CHF)
  9. Uncontrolled hypertension
  10. Severe pulmonary hypertension
  11. Severe aortic stenosis
  12. Orthopedic problems that impair activity
  13. Neurological disorders that limit ability to perform
  14. Dissecting aneurysms

C.  Protocols

  1. Bruce
  2. Naughton
    • Uses 10 exercise periods of 3 minutes duration, each separated by rest periods of 3 minutes.
    • Grade and speed of each time:
      • Period 1:    0%, 1mph 
      • Period 2:   0%, 1.5 mph
      • Period 3:   0%, 2 mph
      • Period 4:   3.5%, 2 mph
      • Period 5:   7%,  2 mph
      • Period 6:   5%, 3 mph
      • Period 7:   7.5%, 3 mph
      • Period 8:    10%, 3 mph
      • Period 9:    12.5%, 3 mph
      • Period 10:  15%, 3 mph
  3. Incremental (sub-maximum) Stress Testing
    • Patient is exercised at workloads less than maximum heart rate
    • Formula:      220 – age (yrs) = maximum heart rate
    • Endpoint of testing is when patient reaches 85% of their maximum heart rate

D. Prep Techniques

  1.  Preparation of the Patient
    • Last meal before exercise should be light, 2 hours before test
    • Avoid cigarettes, alcohol, coffee, tea, carbonated beverages 
    • No heavy exercise before test or on same day
    • Wear properly fitting clothes
    • Room temperature should be 21 degrees – 23 degrees (70-73 F)
  2. Preliminary Procedures
    • Wrapping blood pressure cuff on upper arm (brachial artery)
    • Attach 12-lead EKG and 3-lead cardiotachometer
    • Secure oximeter to ear
    • Show patient how to pedal bicycle or to mount the treadmill
    • Establish intravenous (IV) line
    • Seated and standing 12-lead ECG
    • Have patient hyperventilate prior to testing to document and rule out S-T and T wave abnormalities

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