title: Relationship between pulmonary arterial resistance and compliance among patients with pulmonary arterial hypertension and congenital heart disease.
abstract: It is unknown whether changes in pulmonary arterial resistance (Rp), pulmonary arterial compliance (Cp), and the product of Rp and Cp (the RC time) in patients with pulmonary arterial hypertension (PAH) are related to an increase in pulmonary blood flow. The aim of this study is to clarify relationships between these parameters before and after corrective surgery among patients with PAH and congenital heart disease.
  
  
  
  We performed cardiac catheter examinations and compared Rp, Cp, and the RC time before and after corrective surgery in 100 infants (53 boys) with PAH related to ventricular septal defect.
  
  
  
  Median age at surgery was 2.9 (0.6-28.5) months. Preoperative values of the ratio of pulmonary to systemic blood flow (Qp/Qs), systolic pulmonary arterial pressure (PAP), Rp, Cp, and the RC time were 3.5 (2.7-4.3), 65 (56-70) mm Hg, 2.18 (1.64-3.19) Wood unit/m(2), 2.67 (2.01-3.38) mL/mm Hg/m(2), and 0.36 (0.31-0.40) seconds, respectively. Postoperative systolic PAP, Cp, and the RC time were significantly decreased to 26 (23-29) mm Hg, 1.96 (1.77-2.26) mL/mm Hg/m(2), and 0.31 (0.26-0.36) seconds, respectively, although Rp remained unchanged at 2.53 (2.06-3.31) Wood unit/m(2). The relationship between Rp and Cp was inversely related before and after surgery, and the Rp-Cp coupling curve was shifted downward after surgery. In addition, lower preoperative Cp (partial regression coefficient = -3.35; P = .001) and preterm delivery (partial regression coefficient = 6.28; P = .02) were independently related to postoperative higher systolic PAP.
  
  
  
  Rp-Cp coupling depends on both the amount of pulmonary blood flow and the condition of the pulmonary vasculature. Lower preoperative Cp is an independent predictive factor to predict higher postoperative pulmonary systolic pressure leading to an increase in right ventricular workload. It is necessary to assess Rp-Cp coupling before surgery among patients with PAH related to congenital heart disease.
authors.affiliation: Department of Pediatrics, Japan Community Healthcare Organization, Kyushu Hospital, Kitakyushu, Fukuoka, Japan. Electronic address: jmune@msn.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Muneuchi
authors.affiliation: Department of Pediatrics, Japan Community Healthcare Organization, Kyushu Hospital, Kitakyushu, Fukuoka, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Nagatomo
authors.affiliation: Department of Pediatrics, Japan Community Healthcare Organization, Kyushu Hospital, Kitakyushu, Fukuoka, Japan.
authors.forename: Mamie
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Cardiovascular Surgery, Japan Community Healthcare Organization, Kyushu Hospital, Kitakyushu, Fukuoka, Japan.
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Joo
authors.affiliation: Department of Cardiovascular Surgery, Japan Community Healthcare Organization, Kyushu Hospital, Kitakyushu, Fukuoka, Japan.
authors.forename: Tatsushi
authors.initials: T
authors.lastname: Onzuka
authors.affiliation: Department of Cardiovascular Surgery, Japan Community Healthcare Organization, Kyushu Hospital, Kitakyushu, Fukuoka, Japan.
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Ochiai
authors.affiliation: Department of Pediatrics, Japan Community Healthcare Organization, Kyushu Hospital, Kitakyushu, Fukuoka, Japan.
authors.forename: Kunitaka
authors.initials: K
authors.lastname: Joo
mesh_terms: D062186:Arterial Pressure; D006328:Cardiac Catheterization; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D003187:Compliance; D005260:Female; D006345:Heart Septal Defects, Ventricular / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D006976:Hypertension, Pulmonary / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011651:Pulmonary Artery / Q000503:physiopathology*; D011652:Pulmonary Circulation; D020127:Recovery of Function; D013997:Time Factors; D016896:Treatment Outcome; D014655:Vascular Resistance; D059289:Vascular Stiffness
keywords: RC time constant; compliance; left-to-right shunt; pulmonary arterial hypertension; resistance