Cardiac support device with differential compliance

Abstract

A cardiac support device comprising a jacket of flexible and biocompatible material having a first axis for alignment generally parallel to a longitudinal axis of a patient's heart and a second axis that is transverse to the first axis. The material exhibits an amount of expansion in response to a force applied to the material along the first axis that is different than an amount of expansion in response to the force applied to the material along the second axis.

1 - 16 . (canceled) 
     
     
         17 . A device for treating a disease of a heart, the device comprising:
 a jacket dimensioned to surround at least a lower portion of said heart and sized to snugly conform to an external geometry of said heart to constrain circumferential expansion of said heart during diastole and permit substantially unimpeded contraction of said heart during systole;   said jacket having an open base end sized to be placed over said heart and to surround at least a valvular annulus of said heart and said jacket having a length sized to extend from said base end to an apex end sized to surround said heart near an apex of said heart, a direction between said base end and said apex end defining a longitudinal dimension;   wherein said jacket is constructed from a biocompatible knit material made from non-expandable fibers, wherein the knit material is selected to exhibit an amount of expansion in response to a force applied to said material in a first direction greater than an amount of expansion in response to said force applied to said material in a second direction; and   whereby said jacket is more readily expandable in said longitudinal dimension than in a direction transverse to said longitudinal dimension.   
     
     
         18 . The device of claim  1 , wherein an upper end of the jacket is dimensioned to be positioned in the A-V groove of said heart. 
     
     
         19 . The device of claim  1 , wherein the knit is an atlas knit.