title: Patient-specific finite element modeling of the Cardiokinetix Parachute(®) device: effects on left ventricular wall stress and function.
abstract: The Parachute(®) (Cardiokinetix, Inc., Menlo Park, California) is a catheter-based device intended to reverse left ventricular (LV) remodeling after antero-apical myocardial infarction. When deployed, the device partitions the LV into upper and lower chambers. To simulate its mechanical effects, we created a finite element LV model based on computed tomography (CT) images from a patient before and 6 months after Parachute(®) implantation. Acute mechanical effects were determined by in silico device implantation (VIRTUAL-Parachute). Chronic effects of the device were determined by adjusting the diastolic and systolic material parameters to better match the 6-month post-implantation CT data and LV pressure data at end-diastole (ED) (POST-OP). Regional myofiber stress and pump function were calculated in each case. The principal finding is that VIRTUAL-Parachute was associated with a 61.2 % reduction in the lower chamber myofiber stress at ED. The POST-OP model was associated with a decrease in LV diastolic stiffness and a larger reduction in myofiber stress at the upper (27.1%) and lower chamber (78.4%) at ED. Myofiber stress at end-systole and stroke volume was little changed in the POST-OP case. These results suggest that the primary mechanism of Parachute(®) is a reduction in ED myofiber stress, which may reverse eccentric post-infarct LV hypertrophy.
authors.affiliation: Departments of Surgery, University of California, San Francisco, CA, USA.
authors.forename: Lik Chuan
authors.initials: LC
authors.lastname: Lee
authors.forename: Liang
authors.initials: L
authors.lastname: Ge
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Matthew
authors.initials: M
authors.lastname: Pease
authors.forename: Serjan D
authors.initials: SD
authors.lastname: Nikolic
authors.forename: Rakesh
authors.initials: R
authors.lastname: Mishra
authors.forename: Mark B
authors.initials: MB
authors.lastname: Ratcliffe
authors.forename: Julius M
authors.initials: JM
authors.lastname: Guccione
mesh_terms: D003971:Diastole / Q000502:physiology; D020342:Finite Element Analysis; D006352:Heart Ventricles / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D009203:Myocardial Infarction / Q000601:surgery; D019736:Prostheses and Implants; D014057:Tomography, X-Ray Computed; D016276:Ventricular Function; D020257:Ventricular Remodeling / Q000502:physiology*