title: Modified alternating current defibrillation: a new defibrillation technique.
abstract: OBJECTIVE
  Defibrillation is the only clinically effective treatment for ventricular fibrillation (VF). Early defibrillation improves the outcome and increases the chance of survival with full recovery. Immediate availability of a home-based defibrillator using mains-derived alternating current (AC) current will drastically improve the outcome. The aim was to develop a defibrillator based on the modulated AC, resembling biphasic configuration, and compare its efficacy, in a pig model, with a standard direct current (DC) defibrillator.
  
  
  RESULTS
  A computer controlled, modulated AC defibrillation system was developed using a high-voltage switch and a high-voltage transformer. The efficacy and safety was evaluated in five pigs (30-40 kg), under general anaesthesia with ketamine and isoflouran. A single quadripolar-pacing catheter was inserted percutaneously. Ventricular fibrillation was induced with rapid ventricular burst pacing, and stable VF was defibrillated after 15 s. Defibrillation threshold (DFT) was determined in each animal with AC and standard DC shock using the step-down protocol. A biphasic-like shock was used with a short isoelectric stage between the phases. The DFT with AC was 70.83 +/- 24.81 J and with DC was 65.83 +/- 12.41 J (P = 0.49). No macroscopic damage was observed after AC or DC defibrillation.
  
  
  CONCLUSIONS
  Modulated AC defibrillation is safe and effective as the commercially available DC defibrillation. The defibrillator is built from an inexpensive high-voltage transformer, without the need for capacitor, batteries, or routine maintenance, delivers repeated shock without any delay, and provides pacing as well. It may be an ideal platform for automatic home defibrillator.
authors.affiliation: Heart Institute, Hadassah Hebrew University Medical Center, Jerusalem, Israel. shimonr@ekmd.huji.ac.il
authors.forename: Shimon
authors.initials: S
authors.lastname: Rosenheck
authors.forename: Shraga
authors.initials: S
authors.lastname: Gorni
authors.forename: Ioni
authors.initials: I
authors.lastname: Katz
authors.forename: Asaf
authors.initials: A
authors.lastname: Rabin
authors.forename: Uri
authors.initials: U
authors.lastname: Shpoliansky
authors.forename: Mendel
authors.initials: M
authors.lastname: Mandelbaum
authors.forename: Abraham Teddy
authors.initials: AT
authors.lastname: Weiss
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004554:Electric Countershock / Q000379:methods*; D013552:Swine; D013813:Therapy, Computer-Assisted; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000503:physiopathology / Q000628:therapy*