Beta-receptor downregulation in congenital heart disease: a risk factor for complications after surgical repair?
BACKGROUND
Neurohormonal activation in children with heart failure due to congenital heart disease leads to downregulation of myocardial beta-receptors that may influence the postoperative course after cardiothoracic surgery.


METHODS
Myocardial biopsies of 26 children (aged 14+/-4 months) were obtained from the right atrium during cardiac surgery. Patients were allocated to either of two groups based on the duration of their intensive care unit stay: group 1 comprised those who stayed less than 7 days (n = 17), whereas group 2 comprised those who stayed more than 7 days, plus 3 infants who died during the early postoperative course (n = 9). For beta1- and beta2-mRNA quantitation, real-time polymerase chain reaction with fluorescence-labeled products was used.


RESULTS
Values for myocardial beta1-receptor gene expression were twice as high in group 1 children compared with group 2 (beta1-receptor 0.12+/-0.07 versus 0.06+/-0.03, p = 0.0016; beta2-receptor 0.12+/-0.07 versus 0.06+/-0.03, p = 0.0071). Beta-receptor gene expression in 16 children who received standard treatment for heart failure averaged lower than in the 10 children who received additional propranolol.


CONCLUSIONS
Beta-receptor downregulation due to congestive heart failure has an impact on the postoperative course in children with congenital disease and depends on heart failure therapy.
Buchhorn
Reiner
R
Department of Pediatric Cardiology and Cardiothoracic Surgery, Georg-August-University Göttingen, Germany. rbuchho@gwdg.de
Hulpke-Wette
Martin
M
Ruschewski
Wolfgang
W
Pregla
Reinhard
R
Fielitz
Jens
J
Hetzer
Roland
R
Regitz-Zagrosek
Vera
V
D001706:Biopsy; D002675:Child, Preschool; D004077:Digoxin / Q000008:administration & dosage; D004232:Diuretics / Q000008:administration & dosage; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D004359:Drug Therapy, Combination; D005260:Female; D006330:Heart Defects, Congenital / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006333:Heart Failure / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D017052:Hospital Mortality; D006801:Humans; D007223:Infant; D007902:Length of Stay; D008297:Male; D009206:Myocardium / Q000473:pathology; D011183:Postoperative Complications / Q000188:drug therapy / Q000473:pathology / Q000503:physiopathology*; D011433:Propranolol / Q000008:administration & dosage; D011446:Prospective Studies; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology*; D012307:Risk Factors
D004232:Diuretics; D011943:Receptors, Adrenergic, beta; D004077:Digoxin; D011433:Propranolol