title: Fetal right ventricular myocardial function is better preserved by fibrillatory arrest during fetal cardiac bypass.
abstract: BACKGROUND
  Protection and preservation of fetal myocardial function are important for successful fetal intracardiac repair. Our objective was to determine fetal biventricular cardiac performance after two cardiac-arrest techniques.
  
  
  METHODS
  Three groups of midterm ovine fetuses underwent 90-minute bypass. A control group (no arrest shams, n = 3), and two groups that included 20 minutes of arrest, using fibrillatory (n = 3) or blood cardioplegia (n = 3), were compared. Blood cardioplegia consisted of 4:1 cold blood to crystalloid solution induction every 10 minutes, followed by a warm shot terminal dose before clamp removal. Myocardial function variables from biventricular intracardiac pressure catheters, and 3-axes cardiac sonomicrometry, fetal hemodynamics, and arterial blood gases were continuously recorded. Fetal myocardium was collected for troponin-I analysis at 90 minutes. Statistical analysis was by two-way analysis of variance for repeated measures.
  
  
  RESULTS
  Compared with sham, right ventricular myocardial contractility was reduced with plegia but not fibrillation at 90 minutes after arrest: dP/dt max (511 ± 347 vs 1208 ± 239, p < 0.01) and preload-recruitable stroke work (7.2 ± 8.5 vs 32.3 ± 14.6, p < 0.01). Right ventricular end diastolic pressure-volume relationship (ventricular stiffness) worsened by 90 minutes for plegia vs fibrillation (0.84 ± 0.18 vs 0.25 ± 0.16, p < 0.05). There were no differences in left ventricle performance between groups. Fetal heart rate increased in shams by 30 minutes after arrest compared with both arrest groups (p < 0.05). Right ventricular troponin-I degradation increased with plegia, but not fibrillation, compared with sham (p < 0.05).
  
  
  CONCLUSIONS
  In vivo, fetal right ventricular contractile function deteriorates with a common blood-plegia regimen. Fibrillatory arrest better preserves right ventricular function, the dominant ventricle in fetal life, for short arrest periods.
authors.affiliation: Division of Cardiothoracic Surgery, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA.
authors.forename: Orlando
authors.initials: O
authors.lastname: Petrucci
authors.forename: R Scott
authors.initials: RS
authors.lastname: Baker
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Lam
authors.forename: Casey A
authors.initials: CA
authors.lastname: Reed
authors.forename: Jodie Y
authors.initials: JY
authors.lastname: Duffy
authors.forename: Pirooz
authors.initials: P
authors.lastname: Eghtesady
mesh_terms: D000818:Animals; D002314:Cardioplegic Solutions; D002315:Cardiopulmonary Bypass / Q000379:methods*; D005260:Female; D005333:Fetus / Q000601:surgery*; D006324:Heart Arrest, Induced / Q000379:methods*; D006330:Heart Defects, Congenital / Q000601:surgery*; D006439:Hemodynamics; D011247:Pregnancy; D020127:Recovery of Function; D012756:Sheep; D014693:Ventricular Fibrillation / Q000378:metabolism*; D016278:Ventricular Function, Right
chemical_list: D002314:Cardioplegic Solutions