Heart failure treatment device and method

Abstract

A method and apparatus for treating heart failure is configured to be placed about at least a portion of a patient's heart to apply a mild compressive force on the heart over a range of elastic deformation of the apparatus. The apparatus can be shifted to second range of deformation. In some embodiments, the apparatus is shifted to the second range of deformation by application of a stimulus or alteration of environmental conditions beyond a threshold level.

1 - 32 . (canceled) 
   
   
       33 . An apparatus for implanting on a heart to effect reverse remodeling of the heart, comprising:
 a cardiac harness formed from shape memory material and configured to be substantially smaller than the heart on which it is to be mounted;   the shape memory material being in a thermally-induced martensitic state;   after the cardiac harness is mounted on the heart, the harness will provide a compressive force on the heart in a first elastic range defined by a first diastolic elastic range at the beginning of diastole, and a second diastolic elastic range at the end of diastole; and   the compressive force at the end of diastole being greater than the compressive force at the beginning of diastole.   
   
   
       34 . The apparatus of  claim 33 , wherein the shape memory material comprises Nitinol. 
   
   
       35 . The apparatus of  claim 33 , wherein in response to the heart reverse remodeling, the cardiac harness is responsive to thermal inputs to change the shape memory material from a martensitic state to an austenitic state so that the cardiac harness shrinks and generally hugs the heart. 
   
   
       36 . The apparatus of  claim 35 , wherein the thermal inputs dissipate so that the cardiac harness cools to a point where the shape memory material transforms to a martensitic state and the cardiac harness provides a compressive force on the heart in a second elastic range. 
   
   
       37 . The apparatus of  claim 36 , wherein the second elastic range is under less strain than the first elastic range. 
   
   
       38 . The apparatus of  claim 37 , wherein the second elastic range is defined by a third diastolic elastic range at the beginning of diastole, and a fourth diastolic elastic range at the end of diastole, the third diastolic elastic range being less than the fourth diastolic elastic range. 
   
   
       39 . The apparatus of  claim 38 , wherein the first diastolic elastic range provides about the same or less compressive force on the heart than the third diastolic elastic range and the second diastolic elastic range provides about the same or less compressive force on the heart than the fourth diastolic elastic range.