Overview
Pulmonary artery pressure is the lateral pressure exerted by blood flow through the pulmonary circulation on the pulmonary artery vessels, measured directly from the distal end of a floating catheter, and is categorized into systolic and diastolic pressures. The pulmonary circulation is a high-volume, low-resistance system with a large stretching and volume storage capacity due to the thin and incomplete walls of the pulmonary arterial musculature. The total resistance of the arterial portion of the pulmonary circulation is approximately equal to that of the venous portion, so the pressure drop in the arterial portion of the blood flow is equal to that in the venous portion. Because of the low resistance of the pulmonary vessels to blood flow, pulmonary artery pressure is much lower than aortic pressure, although the output per minute of the right ventricle is essentially equal to that of the left ventricle.
Normal range values for pulmonary artery pressure
Normal pulmonary artery pressure is measured directly by inserting a catheter: systolic pressure is 10 to 30 mmHg; diastolic pressure is 5 to 10 mmHg; mean pressure is 10 mmHg, and the average capillary pressure in the pulmonary circulation can be measured at 7 mmHg.
Clinical significance
Pulmonary artery pressure is an important indicator of hemodynamic detection, which can be measured directly from the distal end of the floating catheter.
1. Elevated pulmonary artery pressure
(1) It is seen in diseases that increase pulmonary vascular resistance, such as pulmonary disorders, hypoxemia. Primary pulmonary hypertension and pulmonary embolism.
(2) In diseases that increase pulmonary venous pressure, such as: mitral valve disease, left ventricular failure increase pulmonary venous pressure, also cause elevated pulmonary artery pressure.
(3) In diseases that increase pulmonary blood flow, left-to-right shunts within the heart, such as atrial septal defects and ventricular septal defects, can increase pulmonary vascular blood flow and pulmonary artery pressure.
2. Decreased pulmonary artery pressure
Hypovolemic state can cause a decrease in pulmonary artery systolic and diastolic pressure.
Diseases that cause a decrease in pulmonary artery systolic pressure include: hypovolemia, pulmonary stenosis, supra- or infra-valvular stenosis, and tricuspid stenosis.