Infant Nasal Nitric Oxide Levels in Congenital Heart Disease

Methods: Parents or legal guardians will be approached to provide written, informed consent. To allow for at least three sub groups of cardiac anomalies (with 20 patients per group), 60 children, less than one year of age, with CHD will be recruited from the Pediatric Cardiology inpatient ward at Stollery Children's Hospital. Sixty age matched controls, without acute respiratory illness, will be recruited from the General Pediatric inpatient ward. All subjects will be breathing room air at the time of nNO measurement. Subjects: This is a pilot study to gather data to power future studies. The investigators aim to recruit 60 subjects with CHD and 60 normal controls without CHD. 60 subjects will allow for at least three sub groups of cardiac anomalies with 20 subjects per group. Control group: The control group will consist of age matched infants, less than one year of age, without CHD or acute respiratory illness. They will also require written informed consent and will have to be breathing room air at the time of the nNO test. Investigational device: For nNO assessment, an inert nitric oxide (NO) sampling line with a disposable foam olive (DirectMed Inc., Glen Cove, NY) will be placed into one of the subject's nostrils while the contralateral nostril is left open. Air will be then sampled at a constant rate of 0.3 Liters/min from the nose by a chemiluminescent analyzer which provides measurement of the nNO level in parts per billion (ppb). All nNO measurements will be performed with the subjects supine. Measurements will be obtained using a NO analyzer (CLD 88 SP, ECO PHYSICS AG, Duerten, Switzerland) available at Stollery Children's Hospital. The analyzer will be calibrated according to the manufacturer's specifications. Two samples will be taken five minutes apart, to assess for test-retest reproducibility, with results for each patient being averaged over the two samples. The test is not painful and each sample takes less than a minute.