title: Device based left ventricular shape change: validation of conductance technology in shape changed hearts.
abstract: We have reported that device based left ventricular (LV) shape change, accomplished by Myosplint, improved LV systolic function by three-dimensional echocardiography (3-D echo). However, evaluation of this device using the pressure-volume relationship is still important. This study was conducted to validate the use of conductance technology for this evaluation in shape-changed hearts. An ex vivo study using excised ovine hearts (n = 11) and an in vivo study using a canine pacing-induced heart failure model (n = 11) were performed. Three Myosplints were implanted. Before and after the shape changes, volumes measured by a conductance catheter were compared with volumes measured by the amount of saline in the ex vivo study or by 3-D echo in the in vivo study. The conductance volumes were linearly correlated with the saline volumes (r2 = 0.961+/-0.046; p < 0.0001) in the ex vivo study and with 3-D echo volumes (r2 = 0.757+/-0.220; p < 0.0001) in the in vivo study. The conductance volumes were linearly correlated with LV volumes even in the shape-changed hearts. This technology can be used to evaluate pressure-volume loops in the shape-changed hearts as long as the conductance volume is calibrated by a reliable method.
authors.affiliation: Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, OH 44195, USA.
authors.forename: Masami
authors.initials: M
authors.lastname: Takagaki
authors.forename: Patrick M
authors.initials: PM
authors.lastname: McCarthy
authors.forename: Raymond
authors.initials: R
authors.lastname: Dessoffy
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Ochiai
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Doi
authors.forename: Michael W
authors.initials: MW
authors.lastname: Howard
authors.forename: Jianxin
authors.initials: J
authors.lastname: Qin
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: C Takahiro
authors.initials: CT
authors.lastname: Shiota
authors.forename: Jason
authors.initials: J
authors.lastname: Connor
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Fukamachi
mesh_terms: D000818:Animals; D006328:Cardiac Catheterization; D002306:Cardiac Volume; D004285:Dogs; D004553:Electric Conductivity; D006333:Heart Failure / Q000628:therapy*; D006353:Heart-Assist Devices; D017379:Hypertrophy, Left Ventricular / Q000628:therapy*; D012756:Sheep; D016277:Ventricular Function, Left