What are the guidelines for diagnosing pulmonary hypertension?

From the Guidelines

Pulmonary hypertension is diagnosed when the mean pulmonary arterial pressure is ≥20 mmHg at rest as measured by right heart catheterization, which is the gold standard diagnostic test. The diagnostic process begins with clinical suspicion based on symptoms such as dyspnea, fatigue, chest pain, and syncope, followed by a stepwise approach to confirm the diagnosis. Initial screening typically involves echocardiography to estimate pulmonary artery pressure and assess right ventricular function. Additional testing includes pulmonary function tests, chest imaging (X-ray and CT scan), ventilation-perfusion (V/Q) scan to rule out chronic thromboembolic pulmonary hypertension, blood tests for connective tissue diseases, HIV, and liver function, and an electrocardiogram to detect right heart strain.

Key Diagnostic Steps

• Clinical suspicion based on symptoms
• Echocardiography for initial screening
• Pulmonary function tests
• Chest imaging (X-ray and CT scan)
• Ventilation-perfusion (V/Q) scan
• Blood tests for connective tissue diseases, HIV, and liver function
• Electrocardiogram to detect right heart strain Once pulmonary hypertension is confirmed, classification into one of five groups (WHO classification) is essential for appropriate treatment planning. The classification includes Group 1 (pulmonary arterial hypertension), Group 2 (due to left heart disease), Group 3 (due to lung diseases/hypoxia), Group 4 (chronic thromboembolic pulmonary hypertension), and Group 5 (unclear/multifactorial mechanisms) 1. Early diagnosis is crucial as pulmonary hypertension is progressive and can lead to right heart failure if left untreated. According to the most recent guidelines, right heart catheterization is recommended to confirm the diagnosis of pulmonary arterial hypertension and to support treatment decisions 1.

From the Research

Diagnostic Guidelines for Pulmonary Hypertension

The diagnosis of pulmonary hypertension (PH) involves a combination of clinical evaluation, non-invasive tests, and invasive procedures. The following are the key guidelines for diagnosing PH:

• Clinical evaluation: Patients with symptoms suggestive of PH, such as dyspnea, exercise intolerance, and chest pain, should undergo a thorough clinical evaluation, including medical history, physical examination, and routine laboratory tests 2, 3.
• Non-invasive tests:
  • Electrocardiography (ECG) to assess right ventricular hypertrophy and strain 2, 3.
  • Chest radiography to evaluate lung fields and cardiac silhouette 2, 3.
  • Pulmonary function tests to assess lung function and detect underlying lung disease 2, 3.
  • Transthoracic echocardiography (TTE) to estimate pulmonary artery pressure, assess right ventricular function, and rule out secondary causes of PH 2, 4, 3, 5, 6.
• Invasive procedures:
  • Right heart catheterization (RHC) to measure pulmonary artery pressure and resistance, and to confirm the diagnosis of PH 2, 3, 5, 6.
  • Ventilation-perfusion scan to exclude chronic thromboembolic PH (CTEPH) 2.
• Classification: PH can be classified into five clinical subgroups:
  • Pulmonary arterial hypertension (PAH)
  • PH due to left-sided heart disease
  • PH due to chronic lung disease
  • CTEPH
  • PH with unclear and/or multifactorial mechanisms 2, 3, 5.

Diagnostic Algorithm

The diagnostic algorithm for PH involves a step-wise approach, starting with clinical evaluation and non-invasive tests, followed by invasive procedures if necessary. The algorithm is as follows:

• Step 1: Clinical evaluation and routine laboratory tests 2, 3.
• Step 2: Non-invasive tests, including ECG, chest radiography, pulmonary function tests, and TTE 2, 4, 3, 5, 6.
• Step 3: RHC to confirm the diagnosis of PH and to assess pulmonary hemodynamics 2, 3, 5, 6.
• Step 4: Ventilation-perfusion scan to exclude CTEPH 2.

Role of Echocardiography

Echocardiography plays a crucial role in the diagnosis and management of PH. TTE can estimate pulmonary artery pressure, assess right ventricular function, and rule out secondary causes of PH 2, 4, 3, 5, 6. Advanced echocardiographic techniques, such as three-dimensional assessment of the right ventricle, can provide additional information on right ventricular structure and function 4.