title: Myocardial metabolism is better preserved after blood cardioplegia in infants.
abstract: BACKGROUND
  We have previously reported improved hemodynamic function after blood cardioplegia in comparison with crystalloid cardioplegia. Furthermore, lactate was released from the heart after crystalloid cardioplegia but not after blood cardioplegia. The purpose of this study was to determine whether the difference in substrate metabolism between the two cardioplegia methods was restricted to lactate, or whether the difference in metabolic derangement was more extensive.
  
  
  METHODS
  Thirty consecutive infants with complete atrioventricular septal defects were included in this prospective, randomized, controlled study. Arterial and coronary sinus blood concentrations of substrates and amino acids were measured after weaning from bypass.
  
  
  RESULTS
  After crystalloid cardioplegia, there was a myocardial uptake of glutamate (p = 0.003), leucine (p = 0.03), lysine (p = 0.003), and beta-hydroxybutyrate (p = 0.004), whereas lactate was released (p = 0.03). After blood cardioplegia, there was a myocardial uptake of free fatty acids (p = 0.01) but no uptake of amino acids and no release of lactate.
  
  
  CONCLUSIONS
  There are differences in myocardial substrate metabolism between blood cardioplegia and crystalloid cardioplegia, which involve carbohydrates and amino acids. The differences may include lipids but our data in this respect are not conclusive.
authors.affiliation: Department of Pediatrics, The Queen Silvia Children's Hospital, Göteborg, Sweden. kerstin.amark@vgregion.se
authors.forename: Kerstin
authors.initials: K
authors.lastname: Amark
authors.forename: Håkan
authors.initials: H
authors.lastname: Berggren
authors.forename: Kerstin
authors.initials: K
authors.lastname: Björk
authors.forename: Annica
authors.initials: A
authors.lastname: Ekroth
authors.forename: Rolf
authors.initials: R
authors.lastname: Ekroth
authors.forename: Krister
authors.initials: K
authors.lastname: Nilsson
authors.forename: Jan
authors.initials: J
authors.lastname: Sunnegårdh
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000097:blood; D000596:Amino Acids / Q000097:blood*; D001011:Aorta; D001639:Bicarbonates / Q000494:pharmacology; D001769:Blood; D001786:Blood Glucose / Q000032:analysis; D002122:Calcium Chloride / Q000494:pharmacology; D002314:Cardioplegic Solutions / Q000494:pharmacology*; D002315:Cardiopulmonary Bypass; D003331:Coronary Vessels; D017558:Elective Surgical Procedures; D004734:Energy Metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods*; D006343:Heart Septal Defects / Q000097:blood / Q000601:surgery; D006801:Humans; D007223:Infant; D007773:Lactates / Q000097:blood*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D017202:Myocardial Ischemia / Q000378:metabolism / Q000517:prevention & control; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000097:blood; D011189:Potassium Chloride / Q000494:pharmacology; D017680:Potassium Compounds / Q000494:pharmacology*; D011446:Prospective Studies; D012965:Sodium Chloride / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D001639:Bicarbonates; D001786:Blood Glucose; D002314:Cardioplegic Solutions; D005230:Fatty Acids, Nonesterified; D007773:Lactates; D017680:Potassium Compounds; C041711:St. Thomas' Hospital cardioplegic solution; C018369:potassium cardioplegic solution; D012965:Sodium Chloride; D011189:Potassium Chloride; D008274:Magnesium; D002122:Calcium Chloride; D010100:Oxygen; D020155:3-Hydroxybutyric Acid