Device based left ventricular shape change: validation of conductance technology in shape changed hearts.
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.
Takagaki
Masami
M
Department of Biomedical Engineering, Lerner Research Institute, The Cleveland Clinic Foundation, OH 44195, USA.
McCarthy
Patrick M
PM
Dessoffy
Raymond
R
Ochiai
Yoshie
Y
Doi
Kazuyoshi
K
Howard
Michael W
MW
Qin
Jianxin
J
Yang
Hua
H
Shiota
C Takahiro
CT
Connor
Jason
J
Fukamachi
Kiyotaka
K
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