From the Guidelines
Normal pulmonary artery (PA) pressures in adults at rest are typically defined as a mean pulmonary artery pressure (mPAP) less than 20 mmHg, with a recent redefinition as mPAP >20 mmHg at rest being diagnostic of pulmonary hypertension 1.
Key Points:
- The mPAP is particularly important clinically, as a sustained elevation above 25 mmHg is diagnostic of pulmonary hypertension.
- Pulmonary artery pressures can be measured directly via right heart catheterization, which remains the gold standard, or estimated non-invasively using echocardiography.
- Factors that can temporarily increase PA pressures include exercise, high altitude, and certain physiological states like pregnancy.
- Clinicians should be aware that PA pressures can vary slightly with respiration, with slightly higher pressures during inspiration due to increased venous return to the right heart.
Definition and Measurement:
- The definition of normal PA pressures is based on the average values obtained from healthy individuals, with an upper limit of normal mPAP being approximately 20 mmHg 1.
- Right heart catheterization is the gold standard for measuring PA pressures, but echocardiography can provide a non-invasive estimate of PA pressures.
Clinical Significance:
- Elevated PA pressures are associated with increased morbidity and mortality, and can be a sign of underlying pulmonary vascular disease or other conditions such as left heart disease or lung disease 1.
- Clinicians should be aware of the potential risks associated with elevated PA pressures and take a multidisciplinary approach to managing patients with this condition.
From the Research
Definition of Normal PA Pressures
Normal pulmonary artery (PA) pressures are defined as a mean pulmonary arterial pressure less than or equal to 25 mm Hg at rest or less than 30 mm Hg during physical activity 2.
PA Pressure Ranges
- Mean pulmonary arterial pressure greater than 25 mm Hg at rest or 30 mm Hg during physical activity is considered pulmonary arterial hypertension 2.
- A resting mean pulmonary artery pressure ≧ 25 mmHg is characterized as a hemodynamic state of pulmonary hypertension (PH) 3.
Diagnosis and Measurement
Diagnosis of PA pressures is typically done through right heart catheterization, which is required to confirm the diagnosis of pulmonary arterial hypertension 2. Echocardiography and exclusion of other causes of symptoms are also essential in the evaluation process 2.
Treatment Options
Treatment options for pulmonary arterial hypertension include oral anticoagulation, diuretics, oxygen supplementation, and for a small percentage of patients, calcium channel blockers 4, 2. Newer treatments include prostacyclin analogues, endothelin receptor antagonists, and phosphodiesterase type 5 inhibitors 4, 5, 2.