RT Book, Section A1 Hoffman, Julien I. E. A2 Rudolph, Colin D. A2 Rudolph, Abraham M. A2 Lister, George E. A2 First, Lewis R. A2 Gershon, Anne A. SR Print(0) ID 7048901 T1 Chapter 492. Pulmonary Hypertension T2 Rudolph's Pediatrics, 22e YR 2011 FD 2011 PB The McGraw-Hill Companies PP New York, NY SN 978-0-07-149723-7 LK accesspediatrics.mhmedical.com/content.aspx?aid=7048901 RD 2024/04/19 AB After about 1 week of age, pulmonary arterial blood pressure is normally under 25/12 mm Hg, and mean pressure is under 18 mm Hg.1,2 Any higher pressure is regarded as pulmonary arterial hypertension, although slight increases are usually not clinically important.