Definitions

1. 
   Claudication:
   Reproducible muscle discomfort or fatigue occurring with exertion at the same workload and relieved with rest, typically due to arterial obstruction.
   
2. 
   Cold extremity:
   Reduced temperature from patient history or observed on physical examination by physician.
   
3. 
   Physiological testing:
   Evaluation of the peripheral circulation based on measurement of limb blood pressures with pulse volume recordings or Doppler waveforms, or other parameters without utilizing data from direct imaging of the blood vessels.
   
4. 
   Resistant hypertension:
   The failure to normalize blood pressure on 3 or more drug regimen with medications at maximum doses and at least 1 of the medications being a diuretic agent.
   
5. 
   Malignant hypertension:
   Uncontrolled hypertension causing acute heart failure, acute renal failure, or acute visual or mental status changes.
   
6. 
   Disease surveillance:
   Baseline physiological testing or imaging:Testing conducted for initial diagnosis or for initial clinical evaluation post surgical or percutaneous intervention.Surveillance:
   Physiological testing or imaging conducted to monitor disease progression based solely on the passage of time since initial diagnosis or revascularization. It is assumed that baseline testing has already been conducted.