title: Novel mechanisms for cerebral blood flow regulation in patients with congenital heart disease.
abstract: BACKGROUND
  The mechanisms that regulate cerebral flow in patients after surgery for congenital heart diseases (CHDs) remain poorly understood. We tested our hypothesis that postoperative patients with CHD have disease- or hemodynamic-specific compensatory mechanisms for maintaining cerebral perfusion.
  
  
  METHODS
  A total of 89 children with specific hemodynamics including Glenn (n = 14), Fontan (n = 19), repaired tetralogy of Fallot (n = 24), and control patients (n = 32) were enrolled. The resistance and blood flow distribution between the brain (Rc and CIc) and lower body (Rs and CIs) were calculated by measuring the hemodynamic changes resulting from inferior vena cava occlusion during cardiac catheterization.
  
  
  RESULTS
  Despite considerable differences in cardiac index and superior vena cava pressure (SVCp), cerebral blood flow was preserved in all noncontrol groups, with a ratio between the vascular resistances in the cerebral and lower body circulation (Rc/Rs) that was significantly lower than that in controls. Interestingly, the reduced Rc/Rs of Glenn patients was mediated by the reduced Rc, whereas augmented Rs was conducive to the reduced Rc/Rs in the Fontan and tetralogy of Fallot groups. Multivariate analysis revealed that high SVCp was significantly associated with low Rc. Although low cardiac index was significantly associated with increased Rc and Rs, its impact was much greater on Rs than on Rc.
  
  
  CONCLUSIONS
  Compensatory mechanisms for cerebral flow regulation occur according to hemodynamic abnormality type in postoperative patients with CHD. Because such a regulation mechanism implies cerebral circulation fragility, further investigations are needed to address the impacts of cerebral circulation properties on neurodevelopmental outcomes.
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Hirofumi
authors: H
authors: Saiki
authors: Department of Pediatrics, Asahikawa Medical University, Asahikawa, Japan.
authors: Masaya
authors: M
authors: Sugimoto
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Seiko
authors: S
authors: Kuwata
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Clara
authors: C
authors: Kurishima
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Yoichi
authors: Y
authors: Iwamoto
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Hirotaka
authors: H
authors: Ishido
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan.
authors: Satoshi
authors: S
authors: Masutani
authors: Department of Pediatric Cardiology, Saitama Medical Center, Saitama Medical University, Saitama, Japan. Electronic address: hsenzaki@saitama-med.ac.jp.
authors: Hideaki
authors: H
authors: Senzaki
mesh_terms: D006328:Cardiac Catheterization; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D018729:Fontan Procedure; D006330:Heart Defects, Congenital / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D008297:Male; D011184:Postoperative Period; D011651:Pulmonary Artery / Q000503:physiopathology; D012039:Regional Blood Flow / Q000502:physiology*; D014655:Vascular Resistance / Q000502:physiology*; D014683:Vena Cava, Superior / Q000503:physiopathology