Relation between plasma nitrate and mean pulmonary arterial pressure in ventricular septal defect.
BACKGROUND
Nitric oxide (NO) is known to modulate myocardial contraction and coronary tone, and its inhalation reduces pulmonary vascular resistance in patients with pulmonary hypertension.


OBJECTIVE
To evaluate the pathophysiological role of NO in patients with a ventricular septal defect (VSD).


METHODS
Twenty-nine children with VSD, nine of whom had undergone VSD closure surgery, and 14 patients with Kawasaki disease. The mean age of the VSD patients was 3.1 years (range, 2 months to 9 years).


METHODS
Using high performance liquid chromatography, nitrate (a more stable NO oxidation product) was measured in plasma specimens of the patients undergoing cardiac catheterisation.


RESULTS
Nitrate concentrations in the pulmonary artery bore a significant relation to mean pulmonary artery pressure, pulmonary to systemic systolic pressure ratio, and pulmonary to systemic flow ratio.


CONCLUSIONS
The concentration of nitrate was in proportion to the increment in intravascular or cardiac pressure, indicating that endogenous NO is upregulated as a compensatory homeostatic attempt to reduce pulmonary pressure and blood flow.
Takaya
J
J
Department of Paediatrics, Kansai Medical University, Osaka, Japan.
Teraguchi
M
M
Nogi
S
S
Ikemoto
Y
Y
Kobayashi
Y
Y
D000704:Analysis of Variance; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006345:Heart Septal Defects, Ventricular / Q000097:blood / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007223:Infant; D008297:Male; D009566:Nitrates / Q000097:blood*; D009569:Nitric Oxide / Q000502:physiology*; D011651:Pulmonary Artery; D011669:Pulmonary Wedge Pressure; D012039:Regional Blood Flow
D009566:Nitrates; D009569:Nitric Oxide