Pulmonary Hypertension Diagnosis

1. Diagnosis: Step 1
   1. Tests
      1. Electrocardiogram (EKG)
         1. Right Ventricular Hypertrophy
      2. Chest XRay
         1. Right Interlobar pulmonary diameter >16 mm
         2. Hilar to thoracic ratio >0.44
   2. Interpretation: Pulmonary Hypertension suggested
      1. Proceed to Step 2 below
2. Diagnosis: Step 2
   1. Tests: Echocardiogram (most useful)
      1. Early findings
         1. Tricuspid regurgitation
         2. Peak pulmonary pressure estimated
            1. Mean right atrial pressure added to
            2. Peak tricuspid jet velocity
      2. Late findings
         1. Right ventricular dilation
         2. Right Ventricular Hypertrophy
   2. Interpretation
      1. Findings not consistent with Pulmonary Hypertension
         1. No further evaluation needed
      2. Findings consistent with Pulmonary Hypertension
         1. No structural heart disease suspected
            1. Follow Step 3 below
         2. Structural heart disease suspected
            1. Cardiac Catheterization (Gold standard)
3. Diagnosis: Step 3
   1. Basic Tests (indicated in all cases)
      1. Complete Blood Count (CBC)
      2. Comprehensive Metabolic Panel (electrolytes, Renal Function tests, Liver Function Tests)
      3. HIV Test
      4. Thyroid Stimulating Hormone (TSH)
      5. Arterial Blood Gas (ABG)
         1. Supplemental Oxygen for all hypoxic patients
      6. Oximetry (6 Minute Walk Test)
      7. Pulmonary Function Tests
      8. Coagulation studies (PTT, INR)
         1. Preparation for Anticoagulation
   2. Additional Tests as indicated
      1. Sleep Study
      2. Sickle Cell Anemia screening
      3. Imaging
         1. CT Chest
         2. Liver Ultrasound
      4. Autoimmune panel
         1. Anticentromere Antibody level
         2. Antinuclear Antibody level
         3. Anti-Scl-70 Antibody level
         4. Ribonucleoprotein Antibody level
   3. Interpretation of Pulmonary Function Tests (PFT)
      1. Severe Chronic Obstructive Lung Disease (COPD)
         1. See COPD Management
      2. Nearly normal PFT
         1. Go to Step 4 below
      3. Severe Restrictive Lung Disease
         1. Go to Step 5 below
4. Diagnosis: Step 4 (Normal PFT Evaluation)
   1. Ventilation Perfusion Scan (V-Q Scan)
      1. Exclude chronic or recurrent Pulmonary Embolism
      2. Preferred over CT due to higher sensitivity for smaller multiple distal emboli
   2. Interpretation of V-Q Scan
      1. No segmental defects
         1. Follow Step 5 below
      2. One or more segmental defects
         1. Obtain Pulmonary Angiogram
         2. Pulmonary Angiogram shows no proximal embolism
            1. Follow Step 5 below
         3. Pulmonary angiogram shows proximal embolism
            1. Treat Pulmonary Embolism
5. Diagnosis: Step 5 (Restrictive Lung Disease Evaluation)
   1. Test: High resolution CT Chest
      1. Exclude Interstitial Lung Disease
      2. Exclude mediastinal fibrosis
   2. Interpretation
      1. Normal or mediastinal fibrosis
         1. Cardiac catheterization
      2. Interstitial Lung Disease
         1. Lung biopsy for tissue diagnosis
6. References
   1. McLaughlin (2009) Circulation 119(16): 2250-94
   2. Nauser (2001) Am Fam Physician 63(9):1789-98
   3. Rubin (1997) N Engl J Med 336:111-7
   4. Rubin (1993) Chest 104:236-50