title: Ischemic postconditioning: brief ischemia during reperfusion converts persistent ventricular fibrillation into regular rhythm.
abstract: OBJECTIVE
  Brief episodes of myocardial ischemia-reperfusion employed during reperfusion after a prolonged ischemic insult may attenuate the total ischemia-reperfusion injury. This phenomenon has been termed ischemic postconditioning. In the present study, we studied the possible effect of postconditioning on persistent reperfusion-induced ventricular fibrillation (VF) in the isolated rat heart model.
  
  
  METHODS
  Isolated Langendorff-perfused rat hearts (n = 46) were subjected to 30 min of regional ischemia and reperfusion. The hearts with persistent VF (n = 11) present after 15 min of reperfusion were then randomly assigned into one of the two groups: (1) control hearts (n = 6) in which perfusion was continued without intervention; (2) postconditioned hearts (n = 5) subjected to 2 min of global ischemia followed by reperfusion. Left ventricular pressures, heart rate, coronary flow, and electrogram were monitored throughout the experiment.
  
  
  RESULTS
  Conversion of VF into regular rhythm was observed in all hearts subjected to postconditioning. Regular beating was maintained by all postconditioned hearts during the subsequent reperfusion. None of the hearts in the control group had normal rhythm at the end of the experiment. At the end of reperfusion, the left ventricular developed pressure was lower in beating postconditioned hearts compared to the hearts that did not develop persistent VF.
  
  
  CONCLUSIONS
  Ischemic postconditioning possesses strong antiarrhythmic effect against persistent reperfusion-induced tachyarrhythmias. Postconditioning may be an interesting, novel adjunct strategy to protect the heart.
authors.affiliation: Department of Pathophysiology and Laboratory of Circulation, St. Petersburg I.P. Pavlov Federal Medical University, Russian Federation.
authors.forename: Michael
authors.initials: M
authors.lastname: Galagudza
authors.forename: Dmitry
authors.initials: D
authors.lastname: Kurapeev
authors.forename: Sarkis
authors.initials: S
authors.lastname: Minasian
authors.forename: Guro
authors.initials: G
authors.lastname: Valen
authors.forename: Jarle
authors.initials: J
authors.lastname: Vaage
mesh_terms: D000818:Animals; D003250:Constriction; D003326:Coronary Circulation; D006339:Heart Rate; D006439:Hemodynamics; D008297:Male; D015425:Myocardial Reperfusion / Q000009:adverse effects / Q000379:methods*; D015428:Myocardial Reperfusion Injury / Q000150:complications*; D051381:Rats; D017208:Rats, Wistar; D014693:Ventricular Fibrillation / Q000209:etiology / Q000628:therapy*