Prepared By Division of Lung Diseases and Office of Prevention, Education, and Control National Heart, Lung, and Blood Institute. Reprinted without permission. The pulmonary artery is the blood vessel carrying oxygen-poor blood from the right ventricle, one of the pumping chambers of the heart, to the lungs. In the lungs, the blood picks up oxygen and then flows to the left side of the heart, where it is pumped by the left ventricle to the rest of the body through the aorta.
Hypertension is the medical term for an abnormally high blood pressure.
Normal mean pulmonary-artery pressure is approximately 14 mmHg at rest. In the PPH patient, the mean blood pressure in the pulmonary artery is greater than 25 mmHg at rest and 30 mmHg during exercise. This increased resistance, in turn, places a strain on the right ventricle, which now has to work harder than usual against the resistance to move adequate amounts of blood through the lungs. The true incidence of primary pulmonary hypertension is unknown. The first reported case occurred in 1891, when E.Romberg, a German doctor, published a description of a patient who, at autopsy, showed thickening of the pulmonary artery but no heart or lung disease that might have caused the condition.