title: Esmolol added in repeated, cold, oxygenated blood cardioplegia improves myocardial function after cardiopulmonary bypass.
abstract: OBJECTIVE
  This study investigated if the β-receptor blocking agent esmolol, added to standard oxygenated blood cardioplegia, improved myocardial function after weaning from bypass.
  
  
  METHODS
  A block-randomized, blinded study.
  
  
  METHODS
  A university laboratory.
  
  
  METHODS
  Twenty anesthetized pigs, Norwegian Landrace.
  
  
  METHODS
  After cardiopulmonary bypass, cardiac arrest was induced with cold (12°C), oxygenated blood cardioplegia, enriched with either esmolol or vehicle, repeated every 20 minutes. After 100 minutes the heart was reperfused and weaned.
  
  
  RESULTS
  Left ventricular function was evaluated with pressure-volume loops, local myocardial function with multilayer strain and strain rate by epicardial short-axis tissue Doppler imaging. One hour after declamping, preload recruitable stroke work did not differ between groups, but increased to 72±3 mmHg in esmolol-treated animals v 57±4 mmHg (p<0.001) in controls after 3 hours. Radial peak ejection strain rate also was increased by esmolol; 6.0±1.0 s(-1)v 2.9±0.3 s(-1) (p<0.001) in subendocardium and 3.9±0.5 s(-1)v 2.3±0.2 s(-1) (p<0.005) in the midmyocardium. Cardiac index was increased, 4.0±0.2 L/min/m(2) by esmolol v 3.3±0.1 L/min/m(2) for controls (p<0.05). Isovolumetric relaxation time constant was reduced by esmolol, 23±1 ms v 26±1 ms (p<0.025). Troponin-T did not differ and was 339±48 ng/L for the esmolol group and 357±55 ng/L for the control group (p = 0.81).
  
  
  CONCLUSIONS
  Esmolol added to blood cardioplegia preserved systolic cardiac function during the first 3 hours after reperfusion in a porcine model with 100 minutes of cardioplegic arrest.
authors.affiliation: Section of Cardiothoracic Surgery, Department of Heart Disease, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science. Electronic address: geir.olav.dahle@helse-bergen.no.
authors.forename: Geir O
authors.initials: GO
authors.lastname: Dahle
authors.affiliation: Section of Cardiothoracic Surgery, Department of Heart Disease, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science.
authors.forename: Pirjo-Riitta
authors.initials: PR
authors.lastname: Salminen
authors.affiliation: Department of Clinical Science.
authors.forename: Christian A
authors.initials: CA
authors.lastname: Moen
authors.affiliation: Section of Cardiothoracic Surgery, Department of Heart Disease, Haukeland University Hospital, Bergen, Norway.
authors.forename: Finn
authors.initials: F
authors.lastname: Eliassen
authors.affiliation: Department of Biomedicine, University of Bergen, Bergen, Norway.
authors.forename: Anne K
authors.initials: AK
authors.lastname: Jonassen
authors.affiliation: Section of Cardiothoracic Surgery, Department of Heart Disease, Haukeland University Hospital, Bergen, Norway; Department of Clinical Science.
authors.forename: Rune
authors.initials: R
authors.lastname: Haaverstad
authors.affiliation: Department of Clinical Science.
authors.forename: Knut
authors.initials: K
authors.lastname: Matre
authors.affiliation: Department of Clinical Science.
authors.forename: Ketil
authors.initials: K
authors.lastname: Grong
mesh_terms: D058671:Adrenergic beta-1 Receptor Antagonists / Q000008:administration & dosage* / Q000378:metabolism; D000818:Animals; D002314:Cardioplegic Solutions / Q000008:administration & dosage / Q000378:metabolism; D002315:Cardiopulmonary Bypass / Q000379:methods* / Q000639:trends; D003080:Cold Temperature; D005260:Female; D006324:Heart Arrest, Induced / Q000379:methods* / Q000639:trends; D008297:Male; D010100:Oxygen / Q000008:administration & dosage* / Q000378:metabolism; D011412:Propanolamines / Q000008:administration & dosage* / Q000378:metabolism; D011897:Random Allocation; D013552:Swine
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D002314:Cardioplegic Solutions; D011412:Propanolamines; C036604:esmolol; D010100:Oxygen
keywords: beta-blockade; cardiac function; cardioplegia; cardiopulmonary bypass; esmolol