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 . 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 patent's heart and a second axis that is transverse to the first axis, wherein 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.  
   
   
       2 . The cardiac support device of  claim 1  wherein the amount of expansion in response to the force applied to the material along the first axis is greater than the amount of expansion in response to the force applied to the material along the second axis.  
   
   
       3 . The cardiac support device of  claim 2  wherein the material is elastic.  
   
   
       4 . The cardiac support device of  claim 3  wherein the material is formed from elongated strands.  
   
   
       5 . The cardiac support device of  claim 4  wherein the elongated strands divide the material into a plurality of open cells.  
   
   
       6 . The cardiac support device of  claim 5  wherein the elongated strands are polymer.  
   
   
       7 . The cardiac support device of  claim 1  wherein the material is elastic.  
   
   
       8 . The cardiac support device of  claim 7  wherein the material is formed from elongated strands.  
   
   
       9 . The cardiac support device of  claim 8  wherein the elongated strands are metal.  
   
   
       10 . The cardiac support device of  claim 9  wherein the elongated strands divide the material into a plurality of open cells.  
   
   
       11 . A cardiac support device comprising a jacket of flexible and biocompatible material having first and second non-parallel axes, wherein 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.  
   
   
       12 . The cardiac support device of  claim 11  wherein the first and second axes are generally transverse to one another.  
   
   
       13 . A method for treating heart disease in a mammal, including: 
 passively constraining expansion of the heart along both a first axis aligned generally parallel to a longitudinal axis of the heart and a second axis that is transverse to the first axis; and    causing the amount of constraint in response to a force applied along the first axis to be different than an amount of constraint in response to a force applied along the second axis.    
   
   
       14 . The method of  claim 13  wherein causing the amount of constraint in response to a force applied along the first axis to be different than an amount of constraint in response to a force applied to the second axis includes causing the amount of constraint in response to a force applied along the first axis to be less than an amount of constraint in response to a force applied to the second axis.  
   
   
       15 . The method of  claim 13  wherein passively constraining expansion of the heart includes applying elastic constraint to the heart.  
   
   
       16 . The method of  claim 13  wherein passively constraining expansion of the heart and causing the amount of constraint in response to a force applied along the first axis to be different than an amount of constraint in response to a force applied to the second axis includes placing on the heart a jacket of flexible and biocompatible material having a first axis for alignment generally parallel to a longitudinal axis of a patent's heart and a second axis that is transverse to the first axis, and wherein 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.  
   
   
       17 . The method of  claim 16  wherein causing the amount of constraint in response to a force applied along the first axis to be different than an amount of constraint in response to a force applied to the second axis includes causing the jacket to have an amount of constraint in response to a force applied along the first axis that is less than an amount of constraint in response to the force applied to the second axis.  
   
   
       18 . The method of  claim 16  wherein placing a jacket on the heart further includes placing a jacket of flexible and elastic biocompatible material on the patient's heart.  
   
   
       19 . A method for treating heart disease in a mammal, including: 
 passively constraining expansion of the heart along both a first axis and a second axis that is non-parallel to the first axis; and    causing the amount of constraint in response to a force applied along the first axis to be different than an amount of constraint in response to a force applied along the second axis.    
   
   
       20 . The method of  claim 19  wherein passively constraining expansion includes passively constraining expansion of the heart along a first axis and a second axis that is transverse to the first axis.