title: Direct epicardial assist device using artificial rubber muscle in a swine model of pediatric dilated cardiomyopathy.
abstract: OBJECTIVE
  Ventricular assist devices are a potent alternative or bridge therapy to heart transplants for dilated cardiomyopathy patients. However, ventricular assist devices have problems related to biocompatibility, hemocompatibility, and thromboembolic events, especially in younger patients. The present study examined the hemodynamic effects of a direct cardiac compression device using circumferential artificial rubber muscles in a young swine model of dilated cardiomyopathy.
  
  
  METHODS
  Dilated cardiomyopathy was established in 6 pigs (6-8 weeks of rapid right ventricular pacing; average weight, 22.6 ± 2.1 kg). The device was designed using pneumatic rubber muscles (Fluidic Muscle, Festo). Hemodynamic parameters were monitored under baseline conditions, after the assistance, and after inducing ventricular fibrillation. Hemodynamic data were acquired using a PiCCO, multilumened thermodilution catheter in the pulmonary artery, left ventricular pressure monitoring, and epicardial echocardiography.
  
  
  RESULTS
  Direct epicardial assistance resulted in a significant improvement in hemodynamic data. Cardiac output improved from 1.39 ± 0.24 L/min to 1.96 ± 0.46 (p = 0.02). Stroke volume (14.5 ± 3.2 mL versus 20.1 ± 4.3 ml, p&lt;0.01) and ejection fraction (25.2 ± 3.6% versus 47.7 ± 7.8%, p&lt;0.01) also improved after assistance. After inducing ventricular fibrillation, cardiac output was maintained at 1.33 ± 0.28 L/min.
  
  
  CONCLUSIONS
  Use of a circumferential direct epicardial assistant device resulted in improvement in hemodynamic data in a dilated cardiomyopathy model. Although there is still a need for improvements in device components, the direct cardiac assist device may be a good alternative to recent heart failure device therapies.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Hirosaki University School of Medicine, Aomori - Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Hirosaki University School of Medicine, Aomori - Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Hirosaki University School of Medicine, Aomori - Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Kondo
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Hirosaki University School of Medicine, Aomori - Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kowatari
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Hirosaki University School of Medicine, Aomori - Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Daitoku
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Hirosaki University School of Medicine, Aomori - Japan.
authors.forename: Masahito
authors.initials: M
authors.lastname: Minakawa
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Hirosaki University School of Medicine, Aomori - Japan.
authors.forename: Ikuo
authors.initials: I
authors.lastname: Fukuda
mesh_terms: D000818:Animals; D002302:Cardiac Output / Q000502:physiology; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology / Q000628:therapy*; D004195:Disease Models, Animal; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology; D012408:Rubber; D013552:Swine; D016277:Ventricular Function, Left / Q000502:physiology
chemical_list: D012408:Rubber