title: Changes in human coronary sinus blood flow and myocardial metabolism induced by ventricular fibrillation and defibrillation.
abstract: BACKGROUND
  During implantation of cardioverter-defibrillators, repeated inductions of ventricular fibrillation and defibrillation are performed. Little is known about the myocardial metabolism associated with ventricular fibrillation and defibrillation in humans.
  
  
  METHODS
  Sixteen patients scheduled for transvenous cardioverter-defibrillator implantation were included in the study. In 10 of the patients, blood samples were taken simultaneously in the coronary sinus and radial artery and analyzed for PO2, PCO2, standard bicarbonate, pH, lactate, alanine, glucose, and glycerol. Oxygen saturation, base excess, and oxygen content were calculated. The patients were studied before, shortly after, and 2 and 5 minutes after successful defibrillation. In six of the patients, coronary sinus blood flow was registered continuously.
  
  
  RESULTS
  The coronary sinus blood flow declined from a basal value of 93 +/- 16 mL/min to 35 +/- 6 mL/min 14 +/- 2 seconds after induction of ventricular fibrillation. Following termination of ventricular fibrillation, coronary sinus blood flow increased to a peak value of 227 +/- 75 mL/min. Oxygen saturation, PO2, and oxygen content in the coronary sinus increased by approximately 25% shortly after each episode of ventricular fibrillation and defibrillation. The coronary sinus lactate increased and the arterio-coronary sinus lactate difference decreased shortly after each of the four episodes, but was normalized within 2 minutes.
  
  
  CONCLUSIONS
  Repeated threshold tests during defibrillator implantation did not cause any long-lasting or cumulative metabolic effects, indicating that the described technique, with a 5-minute recovery period in between episodes, is safe as regards myocardial metabolism.
authors.affiliation: Department of Cardiothoracic Surgery, Karolinska Institute, Karolinska Hospital, Stockholm, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Runsiö
authors.forename: L
authors.initials: L
authors.lastname: Bergfeldt
authors.forename: M
authors.initials: M
authors.lastname: Rosenqvist
authors.forename: A
authors.initials: A
authors.lastname: Owall
authors.forename: L
authors.initials: L
authors.lastname: Jorfeldt
mesh_terms: D000328:Adult; D000368:Aged; D003326:Coronary Circulation; D004554:Electric Countershock; D005260:Female; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000097:blood; D014693:Ventricular Fibrillation / Q000503:physiopathology*
chemical_list: D019344:Lactic Acid; D010100:Oxygen