PT - JOURNAL ARTICLE AU - M Rosenthal AU - A Bush TI - The effects of surgically treated pulmonary stenosis on lung growth and cardiopulmonary function in children during rest and exercise AID - 10.1183/09031936.99.13359099 DP - 1999 Mar 01 TA - European Respiratory Journal PG - 590--596 VI - 13 IP - 3 4099 - http://erj.ersjournals.com/content/13/3/590.short 4100 - http://erj.ersjournals.com/content/13/3/590.full SO - Eur Respir J1999 Mar 01; 13 AB - The effects of high pulmonary blood flow and pressure on pulmonary development are well understood, but the effect of low pulmonary flow/pressure is not. Pulmonary stenosis (PS) was therefore used as a model to determine its effect on lung development, which was assessed noninvasively by carbon monoxide transfer at rest and during exercise. One hundred and six control children (55 males, 8-16 yrs) and 11 children with isolated valvar or subvalvar PS surgically corrected > or =10 yrs prior to the study without residual stenosis/regurgitation were evaluated. Measurements of effective pulmonary blood flow, stroke volume, arteriovenous oxygen difference (AVO), transfer factor and transfer constant, alveolar ventilation and anaerobic threshold were performed using a mass spectrometer. Data from the normal children allowed calculation of z-scores for the study group matched for age, sex, pubertal stage and surface area. PS children at rest had a significantly lower forced expired volume in one second, cardiac frequency and transfer constant with a raised oxygen consumption and AVO which persisted on exercise. During exercise, the cardiac frequency was 12 beats x min(-1) slower and AVO 0.017 L greater than controls (p<0.05). A persistently mildly raised effective functional residual capacity (0.2 L x m(-2)) during exercise led to a reduced transfer constant (0.35 mmol x min(-1) x kPa(-1) x L(-1)), although the percentage rise (28%) from rest to peak exercise was normal. The percentage fall in stroke volume from the penultimate exercise stage to peak exercise stage was greater in PS children (24%, 95% confidence interval 11-37) than control children (2.4, -2-10, p<0.005). In conclusion, although the effects are small, pulmonary stenosis does affect cardiopulmonary function after surgery. This needs to be considered when contemplating the timing of treatment.