title: The myocardial protection of polarizing cardioplegia combined with delta-opioid receptor agonist in swine.
abstract: BACKGROUND
  The purpose of this study was to determine whether polarized arrest using adenosine/lidocaine cold crystalloid cardioplegia in combination with the hibernation inductor δ-opioid receptor agonist pentazocine would give satisfactory myocardial protection rather than using depolarized supranormal potassium cardioplegia, supranormal potassium cardioplegia with pentazocine, or adenosine/lidocaine cardioplegia.
  
  
  METHODS
  Twenty pigs were randomly divided into four groups (n=5 each) to receive the four types of cold crystalloid cardioplegia with an aortic cross-clamp time of 1 hour. Hemodynamic data were continuously measured, as was the left ventricular end-diastolic pressure (LVEDP), left ventricular end-systolic pressure (LVESP), plus or minus derivative of change in diastolic pressure over time (±dp/dt), cardiac output, pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac troponin I, and left ventricular ultrastructure.
  
  
  RESULTS
  Both the adenosine/lidocaine/pentazocine group and the adenosine/lidocaine group got significantly better results than the hyperkalemic and hyperkalemic pentazocine groups in improving hemodynamic values, pulmonary capillary wedge pressure, LVEDP, LVESP, ±dp/dt, cardiac output, cardiac troponin I values, and left ventricular ultrastructure. There were no statistical differences between the adenosine/lidocaine/pentazocine group and the adenosine/lidocaine group at 1 hour after cross-clamp removal; but at 2 hours after cross-clamp removal, the adenosine/lidocaine/pentazocine group stands out (LVEDP 3.3±0.5, LVESP 122.5±18.9, +dp/dt 2.9±0.1, -dp/dt 2.0±0.6, cardiac output 2.6±0.4, and troponin I 4.9±0.5), with significant differences from the adenosine/lidocaine group (LVEDP 5.8±1.0, LVESP 98.5±10.1, +dp/dt 2.5±0.2, -dp/dt 1.0±0.2, cardiac output 2.2±0.2, troponin I 8.2±0.8; p<0.05). The defibrillation rate was largely decreased after the cross-clamp was released in the group containing pentazocine in cardioplegia.
  
  
  CONCLUSIONS
  Adenosine/lidocaine/pentazocine cold crystalloid cardioplegia gave satisfactory cardiac arrest and better myocardial protection than the other three groups, especially with regard to improving prolonged postoperative cardiac function.
authors.affiliation: Department of Cardiopulmonary Bypass, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Wu
authors.forename: Peiqing
authors.initials: P
authors.lastname: Dong
authors.forename: Changcheng
authors.initials: C
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Xiaotong
authors.initials: X
authors.lastname: Hou
mesh_terms: D000241:Adenosine / Q000008:administration & dosage; D000818:Animals; D006321:Heart / Q000187:drug effects*; D006324:Heart Arrest, Induced / Q000379:methods*; D006439:Hemodynamics / Q000187:drug effects; D008012:Lidocaine / Q000008:administration & dosage; D008297:Male; D010423:Pentazocine / Q000008:administration & dosage; D017465:Receptors, Opioid, delta / Q000819:agonists*; D013552:Swine; D013556:Swine, Miniature
chemical_list: D017465:Receptors, Opioid, delta; D008012:Lidocaine; D000241:Adenosine; D010423:Pentazocine