title: Biometal muscle to restore atrial transport function in a permanent atrial fibrillation animal model: a potential tool in the treatment of end-stage heart failure.
abstract: BACKGROUND
  Half of the patients with end-stage heart failure suffer from persistent atrial fibrillation (AF). Atrial kick (AK) accounts for 10-15% of the ejection fraction. A device restoring AK should significantly improve cardiac output (CO) and possibly delay ventricular assist device (VAD) implantation. This study has been designed to assess the mechanical effects of a motorless pump on the right chambers of the heart in an animal model.
  
  
  METHODS
  Atripump is a dome-shaped biometal actuator electrically driven by a pacemaker-like control unit. In eight sheep, the device was sutured onto the right atrium (RA). AF was simulated with rapid atrial pacing. RA ejection fraction (EF) was assessed with intracardiac ultrasound (ICUS) in baseline, AF and assisted-AF status. In two animals, the pump was left in place for 4 weeks and then explanted. Histology examination was carried out. The mean values for single measurement per animal with +/-SD were analysed.
  
  
  RESULTS
  The contraction rate of the device was 60 per min. RA EF was 41% in baseline, 7% in AF and 21% in assisted-AF conditions. CO was 7+/-0.5 l min(-1) in baseline, 6.2+/-0.5 l min(-1) in AF and 6.7+/-0.5 l min(-1) in assisted-AF status (p<0.01). Histology of the atrium in the chronic group showed chronic tissue inflammation and no sign of tissue necrosis.
  
  
  CONCLUSIONS
  The artificial muscle restores the AK and improves CO. In patients with end-stage cardiac failure and permanent AF, if implanted on both sides, it would improve CO and possibly delay or even avoid complex surgical treatment such as VAD implantation.
authors.affiliation: Cardiovascular Surgery Department, CHUV, Lausanne, Switzerland. Piergiorgio.Tozzi@chuv.ch
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Tozzi
authors.forename: Daniel
authors.initials: D
authors.lastname: Hayoz
authors.forename: Steven
authors.initials: S
authors.lastname: Taub
authors.forename: Mirza
authors.initials: M
authors.lastname: Muradbegovic
authors.forename: Elena
authors.initials: E
authors.lastname: Rizzo
authors.forename: Ludwig K
authors.initials: LK
authors.lastname: von Segesser
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D016280:Atrial Function, Right / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D004195:Disease Models, Animal; D004867:Equipment Design; D006325:Heart Atria / Q000473:pathology / Q000503:physiopathology; D006333:Heart Failure / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology; D010138:Pacemaker, Artificial; D012756:Sheep; D014131:Trace Elements
chemical_list: D014131:Trace Elements