title: Early changes in myocardial repolarization and coronary perfusion after cardiopulmonary bypass surgery for ASD repair in children.
abstract: BACKGROUND
  In adults, impaired myocardial repolarization and increased risk of arrhythmia are known consequences of open heart surgery. Little is known, however, about post-operative consequences of cardiopulmonary bypass surgery in children. The aim of this study was to assess ventricular repolarization and coronary perfusion after bypass surgery for atrial septal defect (ASD) repair in children.
  
  
  METHODS
  Twelve patients with ASD were assessed one day before and 5-6 days after ASD repair. Myocardial repolarization (corrected QT interval, QTc, QT dispersion, QTd, and PQ interval) was determined on 12-lead electrocardiograms. Coronary flow in proximal left anterior descending artery (peak flow velocity in diastole, PFVd) was assessed by transthoracic Doppler echocardiography.
  
  
  RESULTS
  Ten of the 12 (83%) children had normal myocardial repolarization before and after surgery. After surgery, QTc increased 1-9% in 5 (42%) patients, decreased 2-11% in 5 (42%) patients and did not change in 2 (16%) patients. Post-op QTc positively correlated with bypass time (R=0.686, p=0.014) and changes in PFVd (R=0.741, p=0.006). After surgery, QTd increased 33-67% in 4 (33%) patients, decreased 25-50% in 6 patients (50%) and did not change in 2 (16%) patients. After surgery, PQ interval increased 5-30% in 4 (33%) patients, decreased 4-29% in 6 (50%) patients and did not change in 1 (8%) patient. Post-op PQ positively correlated with bypass time (R=0.636, p=0.027). As previously reported, PFVd significantly increased after surgery (p<0.001).
  
  
  CONCLUSIONS
  Changes in QTc, PQ and PFVd are common in young children undergoing surgery for ASD repair. Post-op QTc significantly correlates with bypass time, suggesting prolonged cardiopulmonary bypass may impair ventricular repolarization. Post-op QTc significantly correlates with PFVd changes, suggesting increased coronary flow may also impair ventricular repolarization. The clinical significance and reversibility of these alternations require further investigations.
authors.affiliation: Pediatric Department, Section of Pediatric Cardiology, Skane University Hospital, Lund University, Lund, Sweden. e.aburawi@uaeu.ac.ae.
authors.forename: Elhadi H
authors.initials: EH
authors.lastname: Aburawi
authors.forename: Abdul-Kader
authors.initials: AK
authors.lastname: Souid
authors.forename: Petru
authors.initials: P
authors.lastname: Liuba
authors.forename: Taoufik
authors.initials: T
authors.lastname: Zoubeidi
authors.forename: Erkki
authors.initials: E
authors.lastname: Pesonen
mesh_terms: D002315:Cardiopulmonary Bypass / Q000009:adverse effects* / Q000639:trends; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D006329:Heart Conduction System / Q000502:physiology*; D006344:Heart Septal Defects, Atrial / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D007223:Infant; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology*; D013997:Time Factors
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