title: Transient ischaemia induced by rapid cardiac pacing results in myocardial preconditioning.
abstract: OBJECTIVE
  The aim was to determine whether rapid ventricular pacing can protect against the ventricular arrhythmias occurring during a subsequent coronary artery occlusion.
  
  
  METHODS
  The effect was examined of two 2 min periods of pacing (300 beats.min-1) in chloralose-urethane anaesthetised dogs on a subsequent 25 min coronary artery occlusion. Ventricular arrhythmias, ST segment elevation, and inhomogeneity of conduction were analysed.
  
  
  METHODS
  25 anaesthetised mongrel dogs in a restricted body weight range were used.
  
  
  RESULTS
  Preocclusion pacing reduced the severity of occlusion induced ST segment elevation, degree of inhomogeneity, and arrhythmias: ventricular premature beats were reduced from 528(SEM 40) to 136(45), and there were lower incidences of ventricular fibrillation (0% v 47%) and ventricular tachycardia (30% v 80%).
  
  
  CONCLUSIONS
  Rapid ventricular pacing "preconditions" the myocardium in a manner similar to that following short coronary artery occlusions. Short periods of ischaemia no matter how induced protect the heart against the arrhythmogenic effect of a prolonged coronary artery occlusion.
authors.affiliation: Institute of Pharmacology, Albert Szent-Gyorgyi Medical University, Szeged, Hungary.
authors.forename: A
authors.initials: A
authors.lastname: Vegh
authors.forename: L
authors.initials: L
authors.lastname: Szekeres
authors.forename: J R
authors.initials: JR
authors.lastname: Parratt
mesh_terms: D000818:Animals; D001145:Arrhythmias, Cardiac / Q000209:etiology / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects*; D003327:Coronary Disease / Q000209:etiology* / Q000503:physiopathology; D004285:Dogs; D005260:Female; D006321:Heart / Q000503:physiopathology*; D008297:Male; D010805:Physical Conditioning, Animal / Q000379:methods*