Pulmonary Hypertension

PH is defined as a mean pulmonary artery pressure (mPAP) ≥20 mmHg at rest, measured by right heart catheterization (RHC)—the gold standard for diagnosis. For pre-capillary PH, pulmonary vascular resistance (PVR) ≥3 Wood units (WU), and pulmonary artery wedge pressure (PAWP) ≤15 mmHg further refine the diagnosis.

Diagnostic Approach

• Clinical Evaluation: Initial suspicion arises from unexplained exertional dyspnea, fatigue, chest pain, or syncope. Risk factors, comorbidities (such as connective tissue disease, congenital heart disease), and family history should be explored.
• Echocardiography: Assesses right ventricular size/function and estimates systolic pulmonary artery pressure. Also evaluates for left heart disease, valvular disease, and possible congenital shunts.
• Electrocardiogram & Chest X-ray: May suggest right heart strain or enlargement but are neither sensitive nor specific.
• Pulmonary Function Testing & Imaging: Evaluate for parenchymal lung disease; ventilation/perfusion (V/Q) scan or CT pulmonary angiography screens for chronic thromboembolic PH.
• Serology & Laboratory Tests: Autoimmune screening, liver function, HIV and hepatitis screening, as indicated.

Definitive Diagnosis:

Right Heart Catheterization (RHC): Mandatory to confirm elevated pulmonary pressures, assess PVR, and determine left heart filling pressures (PAWP). Vasoreactivity testing may guide therapy selection.