Pulmonary arterial response to hypoxia in survivors of chronic lung disease of prematurity.
BACKGROUND
It is unclear whether increased pulmonary arterial (PA) reactivity to hypoxia observed in preterm infants who develop chronic lung disease of prematurity (CLD) persists into childhood.


OBJECTIVE
We assessed and compared PA pulse wave velocity (PWV) in air and after 12% hypoxia using velocity-encoded MRI between children who had CLD in infancy and preterm-born and term-born controls.


METHODS
From 67 recruited children, 59 (13 CLD, 21 preterm, 25 term), 9-12-year-old children successfully completed the study. Velocity-encoded phase-contrast MR PA images were acquired breathing air and during breathing 12% hypoxia. PA PWV was derived as the ratio of flow to area changes during early systole.


RESULTS
There were no differences in mean (SD) PA PWV between the groups breathing air (CLD=1.3 (0.4) m/s, preterm control=1.3 (0.4) m/s, term control=1.3 (0.3) m/s)) but increased following hypoxia to 1.9 (0.7) m/s, 1.6 (0.6) m/s and 1.5 (0.5) m/s in CLD, preterm and term groups, respectively. The mean differences (95% CI) for PA PWV between CLD and the preterm and control groups were 0.37 (0.08 to 0.70) and 0.34 (0.05 to 0.70), respectively. There was no difference for change in PA PWV with hypoxia between the two control groups, mean difference 0.23 (-0.2 to 0.3).


CONCLUSIONS
Children who had CLD in infancy had increased pulmonary arterial reactivity during hypoxia, thus long-term follow-up is warranted in this population.
Department of Child Health, School of Medicine, Cardiff University, Cardiff, UK.
Chuen Y
CY
Poon
Department of Child Health, School of Medicine, Cardiff University, Cardiff, UK.
William J
WJ
Watkins
Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK.
C John
CJ
Evans
Department of Paediatric Cardiology, Bristol Children's Hospital, Bristol, UK.
Beverly
B
Tsai-Goodman
Nottingham Respiratory Research Unit, University of Nottingham, Nottingham, UK.
Charlotte E
CE
Bolton
Wales Heart Research Institute, School of Medicine, Cardiff University, Cardiff, UK.
John R
JR
Cockcroft
Cardiff University Brain Research Imaging Centre, School of Psychology, Cardiff University, Cardiff, UK.
Richard G
RG
Wise
Department of Child Health, School of Medicine, Cardiff University, Cardiff, UK.
Sailesh
S
Kotecha
D002648:Child; D002908:Chronic Disease; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis / Q000503:physiopathology; D008171:Lung Diseases / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000503:physiopathology; D063177:Pulse Wave Analysis / Q000379:methods; D013223:Statistics as Topic
Cardiology; Neonatology; Respiratory