From the Guidelines
Normal pulmonary artery pressure in adults at rest is typically considered to be less than 20 mmHg, as recently redefined in 2018 1. This definition is based on the mean pulmonary arterial pressure (mPAP) measured at rest, with values above 20 mmHg indicating potential pulmonary hypertension.
- The pulmonary circulation is a low-pressure, low-resistance system designed to optimize gas exchange, with the right ventricle having thinner walls than the left ventricle due to lower resistance.
- Pulmonary artery pressures can be measured directly via right heart catheterization, which remains the gold standard, or estimated non-invasively using echocardiography.
- Elevated pulmonary pressures may indicate various cardiopulmonary conditions, including left heart disease, lung disease, pulmonary embolism, or primary pulmonary arterial hypertension, warranting further investigation.
- The 2018 updated clinical classification of pulmonary hypertension includes five groups, with group 1 being pulmonary arterial hypertension (PAH), and the diagnosis of PH remaining challenging due to its nonspecific symptoms and diverse causes 1.
- A careful history evaluation is critical to evaluate for risk factors for PH, including family history, history of drugs and toxins associated with PH, and other underlying conditions 1.
- The sixth World Symposium on Pulmonary Hypertension defined specific criteria for precapillary PH, isolated postcapillary PH, and combined pre- and postcapillary PH using an mPAP >20 mmHg in combination with pulmonary arterial wedge pressure (PAWP) and peripheral vascular resistance (PVR) measurements 1.
From the Research
Normal Pulmonary Artery Pressure Values
- The normal mean pulmonary artery pressure at rest is approximately 14 ± 3 mmHg 2
- Pulmonary hypertension is defined as a mean pulmonary artery pressure ≥ 20 mmHg at rest 3, 4
- However, some studies suggest that pulmonary hypertension should be defined as a mean pulmonary artery pressure ≥ 25 mmHg at rest 5, 6, 2
- Pulmonary wedge pressure should be < 12 mmHg 3 or ≤ 15 mmHg 2
Pulmonary Artery Pressure During Exercise
- The mean pulmonary artery pressure during exercise is dependent on age and exercise level 3, 6
- In healthy individuals younger than 50 years of age, the mean pulmonary artery pressure during exercise increases in parallel with increasing cardiac output 3
- However, the increase in the mean pulmonary artery pressure during exercise is steeper in healthy individuals aged 50 years and over 3
- During mild exercise, the mean pulmonary artery pressure can exceed 30 mmHg, especially in elderly individuals 6, 2