Method and apparatus to control conduction through the heart to treat cardiac conditions

Abstract

Control of conduction through a heart is described. A lead with a proximal end and a distal end is provided. The distal end of the lead is inserted into a target area. An agent is delivered through the lead to the target area. Delivery of the agent is monitored via a closed loop feedback system.

1 - 21 . (canceled) 
     
     
         22 . A method of treating atrial fibrillation in a patient, the method comprising:
 delivering a therapeutic agent directly into AV nodal tissue of the patient in response to a determination of atrial fibrillation to decrease ventricular rate;   monitoring an electrical response by the heart to the delivered therapeutic agent via a closed loop system, wherein monitoring the electrical response comprises monitoring AV conduction time; and   adjusting a quantity of the therapeutic agent delivered directly to the AV nodal tissue using the closed loop system until a preferred AV conduction time is attained.   
     
     
         23 . The method of  claim 22 , further comprising:
 determining whether AV conduction time is greater than 100 ms;   determining whether AV conduction time is less than 250 ms; and   continuing to deliver the therapeutic agent directly into AV nodal tissue until preferred AV conduction time is attained if the AV conduction time is greater than 100 ms and less than 250 ms.   
     
     
         24 . The method of  claim 22 , further comprising:
 determining whether AV conduction time is less than 100 ms; and   ceasing delivery of the therapeutic agent in response to determining AV conduction time is less than 100 ms.   
     
     
         25 . The method of  claim 24 , further comprising:
 continuing to monitor AV conduction time upon ceasing delivery of the therapeutic agent in response to determining AV conduction time is less than 100 ms; and   delivering therapeutic agent directly into AV nodal tissue if AV conduction time becomes greater than 100 ms after delivery was previously ceased.   
     
     
         26 . The method of  claim 22 , further comprising:
 determining whether AV conduction time is greater than 250 ms; and   determining whether AV block III is present in the patient in response to determining AV conduction time is greater than 250 ms.   
     
     
         27 . The method of  claim 26 , further comprising determining if pacing is required in response to determining that AV block III is present. 
     
     
         28 . The method of  claim 26 , further comprising delivering a quantity of therapeutic agent different than previously being delivered if AV block III is not determined when AV conduction time is greater than 250 ms. 
     
     
         29 . The method of  claim 22 , further comprising:
 determining whether AV conduction time is less than 250 ms; and   delivering the therapeutic agent directly into AV nodal tissue until a preferred AV conduction time is attained if AV conduction time is less than 250 ms.   
     
     
         30 . The method of  claim 22 , further comprising:
 determining whether AV conduction time is greater than 100 ms; and   delivering the therapeutic agent directly into AV nodal tissue until a preferred AV conduction time is attained if AV conduction time is greater than 100 ms.   
     
     
         31 . The method of  claim 22 , further comprising:
 determining whether AV conduction time is greater than 100 ms; and   determining whether AV conduction time is greater than 250 ms in response to determining AV conduction time is greater than 100 ms.   
     
     
         32 . A method of treating atrial fibrillation in a patient, the method comprising:
 delivering a therapeutic agent directly into AV nodal tissue of the patient;   monitoring an electrical response by the heart to the delivered therapeutic agent via a closed loop system, wherein monitoring the electrical response comprises monitoring AV conduction time of the heart;   adjusting a quantity of the therapeutic agent delivered to the AV nodal tissue using the closed loop system until a preferred AV conduction time is attained if AV conduction time is greater than a lower AV conduction time and less than an upper AV conduction time;   ceasing delivery of the therapeutic agent in response to determining AV conduction time is less than the lower AV conduction time; and   determining whether a cardiac condition requiring pacing is present if the AV conduction is greater than the upper AV conduction time.   
     
     
         33 . The method of  claim 32 , wherein the lower AV conduction time is 100 ms and the upper AV conduction time is 250 ms. 
     
     
         34 . The method of  claim 32 , wherein ceasing delivery of the therapeutic agent in response to determining AV conduction time is less that the lower AV conduction time comprises ceasing delivery of the therapeutic agent in response to determining AV conduction time is less than 100 ms. 
     
     
         35 . The method of  claim 32 , further comprising:
 continuing to monitor AV conduction time upon ceasing delivery of the therapeutic agent upon determining AV conduction time is less than the lower AV conduction time; and   delivering therapeutic agent directly into AV nodal tissue if AV conduction time becomes greater than the lower AV conduction time after delivery was previously ceased.   
     
     
         36 . The method of  claim 32 , wherein determining whether a cardiac condition requiring pacing is present if the AV conduction is greater than the upper AV conduction time comprises determining whether AV block III is present in the patient in response to determining AV conduction time is greater than the upper AV conduction time, 
     
     
         37 . The method of  claim 36 , further comprising determining if pacing is required in response to determination that AV block III is present. 
     
     
         38 . The method of  claim 36 , further comprising delivering a quantity of therapeutic agent different than previously being delivered if AV block III is not determined when AV conduction time is greater than the upper AV conduction time. 
     
     
         39 . The method of  claim 32 , wherein adjusting a quantity of the therapeutic agent delivered to the AV nodal tissue using the closed loop system comprises:
 determining whether AV conduction time is less than 250 ms; and   delivering the therapeutic agent directly into AV nodal tissue until a preferred AV conduction time is attained if AV conduction time is less than 250 ms.   
     
     
         40 . The method of  claim 32 , wherein adjusting a quantity of the therapeutic agent delivered to the AV nodal tissue using the closed loop system comprises:
 determining whether AV conduction time is greater than 100 ms; and   delivering the therapeutic agent directly into AV nodal tissue until a preferred AV conduction time is attained if AV conduction time is greater than 100 ms.   
     
     
         41 . The method of  claim 32 , wherein monitoring AV conduction time comprises:
 determining whether AV conduction time is greater than 100 ms; and   determining whether AV conduction time is greater than 250 ms in response to determining AV conduction time is greater than 100 ms.