Methods and apparatus for heart failure treatment

Abstract

Methods and apparatus for assessing the condition of and treating patients for heart failure by the delivery of continuous positive airway pressure are disclosed. Airflow of the patient is measured to determine occurrences of central apneas. A heart failure index is calculated from a count of the number of central apneas that have occurred. The present heart failure index can be compared with a previously calculated heart failure index to determine how the patient's heart failure disease has changed and how it should be treated.

1 . A method for evaluating changes in heart failure disease in a patient comprising steps of: 
 measuring airflow of the patient to determine occurrences of central apneas; calculating a heart failure index from a count of the number of central apneas that have occurred; and comparing a present heart failure index to a previously calculated heart failure index to determine how the patient's heart failure disease has changed.    
   
   
       2 . The method of  claim 1  wherein the occurrences of central apneas are counted over a period ranging from one night to one week.  
   
   
       3 . The method of  claim 2  further comprising a step of identifying subsequent heart failure disease treatment based at least in part upon said heart failure index.  
   
   
       4 . The method of  claim 1  further comprising a step of identifying subsequent heart failure disease treatment based at least in part upon said heart failure index.  
   
   
       5 . A method for monitoring congestive heart failure in a patient comprising steps of: measuring airflow of the patient to determine occurrences of central apneas; calculating a congestive heart failure index from a count of the number of central apneas that have occurred; and comparing a present congestive heart failure index to a previously calculated congestive heart failure index to determine how the patient's congestive heart failure has changed.  
   
   
       6 . The method of  claim 5  wherein the occurrences of central apneas are counted over a period ranging from one night to one week.  
   
   
       7 . The method of  claim 6  further comprising a step of identifying subsequent congestive heart failure treatment based at least in part upon said congestive heart failure index.  
   
   
       8 . The method of  claim 6  further comprising a step of identifying subsequent congestive heart failure treatment based at least in part upon said congestive heart failure index.  
   
   
       9 . An apparatus for evaluation of heart failure in a patient comprising: 
 a means for supplying a controllable level of breathable gas to a patient at a pressure above atmospheric;    a flow sensor to generate a flow signal indicative of the patient's airflow; and    a controller to process said flow signal and control said means for supplying wherein said controller is adapted and configured for: 
 delivering breathable gas at a pressure above atmospheric to said patient from said means for supplying; and  
 calculating a heart failure indicator from said flow signal, said heart failure indicator representing information about the number of central apneas that occurred over a period during which central apneas were detected.  
   
   
   
       10 . The apparatus of  claim 9  wherein the controller is further configured and adapted for controlling a step of identifying subsequent congestive heart failure treatment based at least in part upon said heart failure indicator.  
   
   
       11 . The apparatus of  claim 10  wherein said subsequent congestive heart failure treatment includes a change in the pressure of the breathable gas.  
   
   
       12 . The apparatus of  claim 11  wherein the controller is further configured and adapted for controlling comparing said congestive heart failure indicator to a prior congestive heart failure indicator determined during a previous treatment session.  
   
   
       13 . The apparatus of  claim 10  wherein the controller is further configured and adapted for controlling comparing said congestive heart failure indicator to a prior congestive heart failure indicator determined during a previous treatment session.  
   
   
       14 . The apparatus of  claim 9  wherein the controller is further configured and adapted for controlling comparing said congestive heart failure indicator to a prior congestive heart failure indicator determined during a previous treatment session.  
   
   
       15 . An apparatus for evaluation of heart failure in a patient comprising means for supplying 
 a controllable level of breathable gas to a patient at a pressure above atmospheric;    a flow sensor to generate a flow signal indicative of the patient's airflow; and means for calculating a heart failure indicator from said flow signal, said heart failure indicator representing information about the number of central apneas that occurred over a period during which central apneas were detected.    
   
   
       16 . The apparatus of  claim 15  further including means for determining subsequent heart failure treatment of the patient based at least in part upon said heart failure indicator.  
   
   
       17 . The apparatus of  claim 16  wherein said subsequent heart failure treatment includes a change in the pressure of the breathable gas.  
   
   
       18 . The apparatus of  claim 16  further including means for comparing said heart failure indicator to a prior heart failure indicator determined during a previous treatment session.  
   
   
       19 . The apparatus of  claim 15  further including means for comparing said heart failure indicator to a prior heart failure indicator determined during a previous treatment session.