Vagal stimulation for cardioversion of atrial fibrillation

Abstract

Apparatus ( 20 ) for treating a subject ( 30 ) suffering from spontaneous atrial fibrillation includes an electrode device ( 22 ), adapted to be coupled to a site of the subject ( 30 ) selected from the list consisting of: a vagus nerve ( 24 ) of the subject ( 30 ), an epicardial fat pad of the subject ( 30 ), a pulmonary vein of the subject ( 30 ), a carotid artery of the subject ( 30 ), a carotid sinus of the subject ( 30 ), a vena cava vein of the subject ( 30 ), and an internal jugular vein of the subject ( 30 ), and a control unit ( 32 ), adapted to drive the electrode device ( 22 ) to apply an electrical current to the site, and to configure the current to maintain the spontaneous AF for at least about 24 hours, so as to modify blood flow within the atria and reduce risk of thromboembolic events.

1 - 45 . (canceled)  
     
     
         46 . Apparatus according to  claim 361 , wherein the control unit is adapted to induce the cardioversion by repeatedly changing at least one parameter of the current.  
     
     
         47 - 48 . (canceled)  
     
     
         49 . Apparatus according to  claim 46 , wherein the parameter includes an amplitude of the current, and wherein the control unit is adapted to induce the cardioversion by repeatedly changing the amplitude.  
     
     
         50 . Apparatus according to  claim 46 , wherein the parameter includes a frequency of the current, and wherein the control unit is adapted to induce the cardioversion by repeatedly changing the frequency.  
     
     
         51 - 56 . (canceled)  
     
     
         57 . Apparatus according to  claim 46 , wherein the control unit is adapted to induce the cardioversion by repeatedly changing the parameter according to a predetermined pattern.  
     
     
         58 - 84 . (canceled)  
     
     
         85 . Apparatus according to  claim 361 , wherein the control unit is adapted to apply the current in respective bursts in each of a plurality of cardiac cycles of the subject.  
     
     
         86 - 97 . (canceled)  
     
     
         98 . Apparatus according to  claim 361 , 
 wherein the control unit is adapted to:    during a first period beginning upon detecting the AF, configure the current to attempt to induce the cardioversion    determine whether the cardioversion has been induced, and    during a second period beginning responsive to determining that the cardioversion has not been induced within a threshold period of time after detecting the AF, configure the current to maintain the AF.    
     
     
         99 - 106 . (canceled)  
     
     
         107 . Apparatus according to  claim 98 , comprising a pacing device, adapted to be applied to a heart of the subject, wherein the control unit is adapted to attempt to induce the cardioversion during the first period by: 
 during a pacing period within the first period, driving the pacing device to pace the heart, and driving the electrode device to apply the current to the site, and    during a withholding period following the pacing period, withholding the electrode device from applying the current to the site.    
     
     
         108 - 188 . (canceled)  
     
     
         189 . A method according to  claim 365 , wherein inducing the cardioversion comprises inducing the cardioversion by repeatedly changing at least one parameter of the current.  
     
     
         190 - 191 . (canceled)  
     
     
         192 . A method according to  claim 189 , wherein the parameter includes an amplitude of the current, and wherein repeatedly changing the parameter comprises repeatedly changing the amplitude of the current.  
     
     
         193 . A method according to  claim 189 , wherein the parameter includes a frequency of the current, and wherein repeatedly changing the parameter comprises repeatedly changing the frequency of the current.  
     
     
         194 - 199 . (canceled)  
     
     
         200 . A method according to  claim 189 , wherein repeatedly changing the parameter comprises repeatedly changing the parameter according to a predetermined pattern.  
     
     
         201 - 227 . (canceled)  
     
     
         228 . A method according to  claim 365 , wherein applying the current comprises applying the current in respective bursts in each of a plurality of cardiac cycles of the subject.  
     
     
         229 - 240 . (canceled)  
     
     
         241 . A method according to  claim 365 , 
 wherein inducing the cardioversion comprises inducing the cardioversion during a first period beginning upon detecting the AF, and    wherein the method comprises:    determining whether the cardioversion has been induced; and    during a second period beginning responsive to determining that the cardioversion has not been induced within a threshold period of time after detecting the AF, configuring the current to maintain the AF.    
     
     
         242 - 250 . (canceled)  
     
     
         251 . A method according to  claim 241 , wherein inducing the cardioversion comprises: 
 during a pacing period within the first period, pacing a heart of the subject, and applying the current to the site, and    during a withholding period following the pacing period, withholding applying the current to the site.    
     
     
         252 - 360 . (canceled)  
     
     
         361 . Treatment apparatus, comprising: 
 an electrode device, configured to be coupled to a site of a subject suffering from atrial fibrillation (AF), the site selected from the group consisting of: a vagus nerve of the subject, an epicardial fat pad of the subject, a pulmonary vein of the subject, a carotid artery of the subject, a carotid sinus of the subject, a vena cava vein of the subject, and an internal jugular vein of the subject;    a sensor, configured to detect an occurrence of the AF and generate a sensor signal indicative thereof; and    a control unit, configured to receive the sensor signal, and, responsively thereto, to induce cardioversion by driving the electrode device to apply an electrical current to the site.    
     
     
         362 . Apparatus according to  claim 361 , wherein the control unit is configured to induce the cardioversion by configuring the current to stimulate autonomic nervous tissue in the site.  
     
     
         363 . Apparatus according to  claim 361 , wherein the site includes the vagus nerve, and wherein the electrode device is configured to be coupled to the vagus nerve.  
     
     
         364 . Apparatus according to  claim 361 , wherein the site includes the epicardial fat pad, and wherein the electrode device is configured to be coupled to the epicardial fat pad.  
     
     
         365 . A treatment method, comprising: 
 detecting an occurrence of atrial fibrillation (AF) in a subject; and    responsively to the detecting, inducing cardioversion of the AF by applying an electrical current to a site of the subject selected from the group consisting of: a vagus nerve of the subject, an epicardial fat pad of the subject, a pulmonary vein of the subject, a carotid artery of the subject, a carotid sinus of the subject, a vena cava vein of the subject, and an internal jugular vein of the subject.    
     
     
         366 . A method according to  claim 365 , wherein inducing the cardioversion comprises configuring the current to stimulate autonomic nervous tissue in the site.  
     
     
         367 . A method according to  claim 365 , wherein the site includes the vagus nerve, and wherein applying comprises applying the current to the vagus nerve.  
     
     
         368 . A method according to  claim 365 , wherein the site includes the epicardial fat pad, and wherein applying comprises applying the current to the epicardial fat pad.