Myocardial substrates in children with congenital heart disease: relationship to substrate supply, age, growth and desaturation.
OBJECTIVE
The myocardial uptake of substrates in children has only been investigated on a small scale. The purpose of this study was to define myocardial substrate uptake in relation to the arterial supply of substrates, age, growth and oxygen saturation.


METHODS
Thirty patients with congenital heart disease, aged 3 months to 16 years, were studied during cardiac catheterization. Arterial and coronary sinus blood was analyzed for the major fuel metabolites and amino acids.


RESULTS
The uptake of all major substrates correlated significantly with the arterial supply: free fatty acids (r = 0.52, p = 0.004), beta-hydroxybutyrate (r = 0.74, p < 0.0001), lactate (r = 0.70, p < 0.0001) and glucose (r = 0.48, p = 0.01). Free fatty acids were the dominant substrate, irrespective of age, growth and saturation. With age, there was an increase in the uptake of lactate (r = 0.61, p = 0.0004) and a decrease in the uptake of beta-hydroxybutyrate (r =-0.41, p = 0.02). In multivariate analyses, these changes were explained by the arterial supply of the substrates, while age per se did not contribute significantly.


CONCLUSIONS
The uptake of myocardial metabolites correlated with the arterial supply. Free fatty acids were the dominant substrate at all ages. The uptake of lactate and beta-hydroxybutyrate, although varying with age, was also determined by the arterial supply.
Amark
Kerstin
K
Department of Pediatrics, The Queen Silvia Children's Hospital, Göteborg University, Göteborg, Sweden. kerstin.amark@vgregion.se
Ekroth
Rolf
R
Nilsson
Krister
K
Sunnegårdh
Jan
J
Söderberg
Björn
B
D020155:3-Hydroxybutyric Acid / Q000097:blood; D000293:Adolescent; D000367:Age Factors; D000704:Analysis of Variance; D001774:Blood Chemical Analysis; D001786:Blood Glucose; D006328:Cardiac Catheterization; D002648:Child; D002675:Child, Preschool; D003331:Coronary Vessels / Q000378:metabolism; D005227:Fatty Acids / Q000097:blood; D018698:Glutamic Acid / Q000097:blood; D048788:Growth and Development; D006330:Heart Defects, Congenital / Q000378:metabolism*; D006801:Humans; D007223:Infant; D019344:Lactic Acid / Q000097:blood; D007930:Leucine / Q000097:blood; D017202:Myocardial Ischemia / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D010101:Oxygen Consumption; D012044:Regression Analysis; D013548:Sweden
D001786:Blood Glucose; D005227:Fatty Acids; D019344:Lactic Acid; D018698:Glutamic Acid; D007930:Leucine; D020155:3-Hydroxybutyric Acid