title: Adenosine preconditioning reduces both pre and postischemic arrhythmias in human myocardium.
abstract: BACKGROUND
  Consistently, clinical series record supraventricular tachyarrhythmias in approximately 30% of patients following coronary artery bypass surgery (CABG). Ischemic preconditioning and adenosine preconditioning (Ado-PC) decrease postischemia/reperfusion (I/R) myocardial stunning, infarct size, and pharmacologically induced arrhythmias in all species including man. We hypothesized that adenosine preconditioning would decrease spontaneous pre- and postischemic atrial arrhythmias in human myocardium. The purposes of this study were to determine the effect of in vivo and in vitro Ado-PC on atrial arrhythmias.
  
  
  METHODS
  Human atrial trabeculae were harvested from CABG patients, placed in organ baths, and paced (1 Hz). Developed force (DF) was recorded during simulated I/R (30/45 min). Prior to I/R, trabeculae were treated with Ado (125 microM) for 5 min (in vitro), or patients were treated with Ado (12 mg iv) 5 min (in vivo) prior to harvest of trabeculae. Contraction frequency >4 Hz (defined as atrial tachyarrhythmias) was recorded in all groups pre- and postischemia.
  
  
  RESULTS
  Control trabeculae exhibited increased tachyarrhythmias pre- and postischemia. In vivo and in vitro Ado-PC suppressed both pre- and postischemic arrhythmias.
  
  
  CONCLUSIONS
  Adenosine preconditioning suppresses the frequency of pre- and postischemic tachyarrhythmias against an ischemia/reperfusion insult in human myocardium. This antiarrhythmic effect occurs with both in vitro and in vivo administration of adenosine. Preconditioning with adenosine prior to elective ischemia/reperfusion is a promising strategy of reducing spontaneous atrial arrhythmias in patients undergoing myocardial revascularization.
authors.affiliation: Department of Surgery, University of Colorado Health Sciences Center, Denver, Colorado 80262, USA. ben.pomerantz@uchsc.edu
authors.forename: B J
authors.initials: BJ
authors.lastname: Pomerantz
authors.forename: K
authors.initials: K
authors.lastname: Joo
authors.forename: B D
authors.initials: BD
authors.lastname: Shames
authors.forename: J C
authors.initials: JC
authors.lastname: Cleveland
authors.forename: A
authors.initials: A
authors.lastname: Banerjee
authors.forename: A H
authors.initials: AH
authors.lastname: Harken
mesh_terms: D000241:Adenosine / Q000008:administration & dosage*; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage*; D001026:Coronary Artery Bypass; D004562:Electrocardiography; D006801:Humans; D066298:In Vitro Techniques; D019157:Ischemic Preconditioning, Myocardial; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000188:drug therapy* / Q000601:surgery; D015428:Myocardial Reperfusion Injury / Q000188:drug therapy / Q000601:surgery; D013617:Tachycardia, Supraventricular / Q000175:diagnosis / Q000188:drug therapy*
chemical_list: D000889:Anti-Arrhythmia Agents; D000241:Adenosine