title: Coronary flow and reactivity, but not arrhythmia vulnerability, are affected by cardioplegia during cardiopulmonary bypass in piglets.
abstract: BACKGROUND
  Surgery under cardiopulmonary bypass (CPB) is still associated with significant cardiovascular morbidity in both pediatric and adult patients but the mechanisms are not fully understood. Abnormalities in coronary flow and function have been suggested to play an important role. Prior studies suggest protective effects on coronary and myocardial function by short intravenous (i.v.) infusion of cyclosporine A before CPB.
  
  
  METHODS
  Barrier-bred piglets (10-12 kg, n=20) underwent CPB for 45 min, with or without antegrade administration of cardioplegic solution. Prior to CPB, half of the animals in each group received an i.v. infusion of 100 mg/kg cyclosporine A. The left anterior descending coronary flow velocity responses to adenosine, serotonin, and atrial pacing, as well as left ventricular function and postsurgical vulnerability to atrial fibrillation (Afib) were assessed by intracoronary Doppler, epicardial echocardiography, and in vivo electrophysiological study, before and 8 hours after surgery. Plasma C-reactive protein (CRP) and fibrinogen were measured at both time-points.
  
  
  RESULTS
  Cyclosporine infusion did not influence any of the studied variables (p>0.4). Coronary peak flow velocity (cPFV) rose significantly after surgery especially in the cardioplegia group (p<0.01 vs. non-cardioplegia group and pre-surgery). cPFV responses to adenosine, but not to serotonin, tended to decrease (p=0.06) after surgery only in cardioplegia group (p=0.06; p=0.8 in non-cardioplegia group vs pre-surgery). Also, cPFV response to atrial pacing was lower in the cardioplegia than in the non-cardioplegia group (p=0.02). Neither vulnerability nor duration of induced Afib after CPB differed between groups (Chi-square p=0.4). Cyclosporine had no significant effect on coronary indexes or arrhythmia vulnerability (p>0.4). There was no difference in systolic myocardial function between groups at any time point.
  
  
  CONCLUSIONS
  In piglets, CPB with cardioplegia was associated with profound abnormalities in coronary vasomotor tone and receptor-related flow regulation, whereas arrhythmia vulnerability appeared to be comparable with that in non-cardioplegia group. In this study, preconditioning with cyclosporine had no detectable protective effect on coronary circulation or arrhythmia vulnerability after CPB.
authors.affiliation: Division of Cardiology, Children's Heart Center, Skåne University Hospital, Lund, Sweden. petru.liuba@med.lu.se
authors.forename: Petru
authors.initials: P
authors.lastname: Liuba
authors.forename: Sune
authors.initials: S
authors.lastname: Johansson
authors.forename: Erkki
authors.initials: E
authors.lastname: Pesonen
authors.forename: Michal
authors.initials: M
authors.lastname: Odermarsky
authors.forename: Axel
authors.initials: A
authors.lastname: Kornerup-Hansen
authors.forename: Anders
authors.initials: A
authors.lastname: Forslid
authors.forename: Elhadi H
authors.initials: EH
authors.lastname: Aburawi
authors.forename: Thomas
authors.initials: T
authors.lastname: Higgins
authors.forename: Malene
authors.initials: M
authors.lastname: Birck
authors.forename: Valeria
authors.initials: V
authors.lastname: Perez-de-Sa
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D001145:Arrhythmias, Cardiac / Q000378:metabolism / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology; D002097:C-Reactive Protein / Q000378:metabolism; D002315:Cardiopulmonary Bypass; D003326:Coronary Circulation / Q000502:physiology*; D016572:Cyclosporine / Q000494:pharmacology; D004452:Echocardiography; D004562:Electrocardiography; D005340:Fibrinogen / Q000378:metabolism; D006324:Heart Arrest, Induced / Q000379:methods*; D013552:Swine
chemical_list: D016572:Cyclosporine; D005340:Fibrinogen; D002097:C-Reactive Protein