From the Guidelines
Pulmonary hypertension is best evaluated through a combination of diagnostic tests, with right heart catheterization being the gold standard, as it directly measures pulmonary artery pressures and confirms the diagnosis when mean pulmonary artery pressure exceeds 20 mmHg at rest, as recommended by the 2023 European Society of Cardiology quality indicators for the care and outcomes of adults with pulmonary arterial hypertension 1. The diagnostic approach to pulmonary hypertension typically starts with non-invasive tests to estimate pulmonary artery pressure and assess right ventricular function.
- Echocardiography is usually the first screening test, providing estimates of pulmonary artery pressure and assessing right ventricular function and structure.
- Additional tests include:
- Pulmonary function tests to identify underlying lung disease
- Arterial blood gases to evaluate oxygenation
- Ventilation-perfusion (V/Q) scan to detect blood clots
- Chest CT scans to examine lung parenchyma and pulmonary vessels
- Chest X-rays to look for enlarged pulmonary arteries or heart chambers
- Six-minute walk tests help assess exercise capacity and disease severity, while blood tests may include BNP/NT-proBNP levels to evaluate heart strain, HIV testing, liver function tests, and autoimmune markers to identify potential causes, as outlined in the 2017 ACR Appropriateness Criteria for suspected pulmonary hypertension 1. The 2015 ESC/ERS guidelines for the diagnosis and treatment of pulmonary hypertension also recommend right heart catheterization to confirm the diagnosis of pulmonary arterial hypertension (PAH) and to support treatment decisions, as well as vasoreactivity testing in patients with IPAH, HPAH, and PAH induced by drug use 1. Overall, a comprehensive testing approach is crucial for determining both the presence and underlying cause of pulmonary hypertension, which is essential for appropriate treatment planning, as emphasized by the 2023 European Society of Cardiology quality indicators 1.
From the Research
Tests to Evaluate Pulmonary Hypertension
The following tests are used to evaluate pulmonary hypertension:
- Clinical history and physical examination
- Standard chest radiography
- Electrocardiography
- Transthoracic Doppler echocardiography 2, 3, 4, 5, 6
- Pulmonary function tests
- Arterial blood gas analysis
- Ventilation and perfusion lung scan
- High-resolution computed tomography of the lungs
- Contrast-enhanced spiral computed tomography of the lungs
- Pulmonary angiography
- Blood tests and immunology
- Abdominal ultrasound scan
- Exercise capacity assessment
- Hemodynamic evaluation
Role of Echocardiography
Echocardiography plays a key role in the diagnosis and management of patients with pulmonary hypertension:
- It provides an estimate of pulmonary artery pressure and resistance, right atrial pressure, as well as indirect information about right heart structure and function 4
- It is useful in ruling out secondary causes of pulmonary hypertension, such as left heart disease or congenital heart disease 3, 5
- It is valuable in assessing prognosis and treatment options, monitoring the efficacy of specific therapeutic interventions, and detecting the preclinical stages of disease 2, 3, 5
Limitations of Echocardiography
While echocardiography is a useful tool, it has some limitations:
- It is insufficiently precise as a single tool for the ultimate diagnosis of pulmonary hypertension, with right heart catheterization considered the gold standard technique 2, 5
- It may not provide accurate measurements of pulmonary hemodynamics in all cases, and advanced noninvasive imaging techniques may be necessary to provide additional information 6