Abstract: A method is provided, including identifying that a subject is at risk of suffering from atrial fibrillation (AF). Responsively to the identifying, a risk of an occurrence of an episode of the AF is reduced by applying an electrical current to a site of the subject selected from the group consisting of: a vagus nerve, a sinoatrial (SA) node fat pad, a pulmonary vein, a carotid artery, a carotid sinus, a coronary sinus, a vena cava vein, a jugular vein, an azygos vein, an innominate vein, and a subclavian vein, and configuring the current to stimulate autonomic nervous tissue in the site. Other embodiments are also described.

Abstract: Apparatus is provided including an implantable sensor, adapted to sense an electrical parameter of a heart of a subject, and a first control unit, adapted to apply pulses to the heart responsively to the sensed parameter, the pulses selected from the list consisting of: pacing pulses and anti-arrhythmic energy. The apparatus further includes an electrode device, adapted to be coupled to a site of the subject selected from the list 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 coronary sinus of the subject, a vena cava vein of the subject, a right ventricle of the subject, and a jugular vein of the subject; and a second control unit, adapted to drive the electrode device to apply to the site a current that increases parasympathetic tone of the subject and affects a heart rate of the subject. The first and second control units are not under common control.

Abstract: Apparatus is provided including an electrode device and a control unit. The electrode device is configured to be coupled to a site of a subject selected from the group consisting of: a vagus nerve, an epicardial fat pad, a pulmonary vein, a carotid artery, a carotid sinus, a coronary sinus, a vena cava vein, a right ventricle, a right atrium, and a jugular vein.

Abstract: Apparatus is provided for application to a nerve of a subject, including an electrode cuff, which includes a housing, which is configured to be placed at least partially around the nerve so as to define an inner surface of the housing that faces the nerve. A plurality of insulating elements are coupled to the inner surface of the housing at respective insulating element longitudinal positions along the housing, such that the inner surface of the housing and pairs of the insulating elements define one or more respective cavities at respective cavity longitudinal positions along the housing. One or more electrodes are fixed to the housing in fewer than all of the cavities, such that at least one of the cavities is an empty cavity that does not have an electrode positioned therein. Other embodiments are also described.

Abstract: A treatment method is provided, including identifying a subject as one who is selected to undergo an interventional medical procedure, and, in response to the identifying, reducing a likelihood of a potential adverse effect of the procedure by applying an electrical current to a parasympathetic 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 coronary sinus of the subject, a vena cava vein of the subject, a jugular vein of the subject, a right ventricle of the subject, a parasympathetic ganglion of the subject, and a parasympathetic nerve of the subject.

Abstract: Apparatus is provided including an implantable sensor, adapted to sense an electrical parameter of a heart of a subject, and a first control unit, adapted to apply pulses to the heart responsively to the sensed parameter, the pulses selected from the list consisting of: pacing pulses and anti-arrhythmic energy. The apparatus further includes an electrode device, adapted to be coupled to a site of the subject selected from the list 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 coronary sinus of the subject, a vena cava vein of the subject, a right ventricle of the subject, and a jugular vein of the subject; and a second control unit, adapted to drive the electrode device to apply to the site a current that increases parasympathetic tone of the subject and affects a heart rate of the subject. The first and second control units are not under common control.

Abstract: Apparatus is provided including an electrode device and a control unit. The electrode device is configured to be coupled to a site of a subject selected from the group consisting of: a vagus nerve, an epicardial fat pad, a pulmonary vein, a carotid artery, a carotid sinus, a coronary sinus, a vena cava vein, a right ventricle, a right atrium, and a jugular vein.

Abstract: This invention provides a method for treating a condition of a subject, comprising identifying the subject as suffering from heart failure; treating the heart failure by applying a stimulating current to parasympathetic nervous tissue of the subject, and configuring the stimulating current to change a level of protein expression of at least one NO synthase of the subject selected from the group consisting of: NOS-1, NOS-2, and NOS-3; and thereafter, measuring the level of the protein expression of at least one NO synthase, and evaluating an effectiveness of the current application by assessing at least one change in the level of the protein expression of at least one NO synthase.

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.

Abstract: Apparatus is provided for applying current to a nerve, including a housing, that is adapted to be placed in a vicinity of the nerve. At least one electrode is fixed to the housing such that the at least one electrode does not come in direct physical contact with the nerve, and such that the electrode surrounds greater than 180 degrees of a circumference of the nerve after the placement of the housing. Two end insulating elements are fixed to the housing. The at least one electrode is between the end insulating elements. A characteristic closest end insulating element distance to a surface of the nerve is less than 0.5 mm.

Abstract: A method is provided that includes surgically implanting an electrode device having a cuff and one or more electrodes mounted in the cuff, by placing the electrode device around a nerve such that the electrodes face the nerve. Conductive solution is introduced into the electrode device such that the solution is in contact with both the electrodes and the nerve. During implantation of the electrode device, an impedance is measured between one or more of the electrodes and an electrical contact point in electrical communication with the electrode device. Responsively to the impedance measurement, it is determined whether the electrode device is correctly sized for the nerve, and, if not, the electrode device is removed and another electrode device having a different size is implanted. Other embodiments are also described.

Abstract: Apparatus is provided that includes an electrode device, adapted to be coupled to a vagus nerve of a subject, and a control unit, adapted to drive the electrode device to apply to the vagus nerve a current that reduces heart rate variability of the subject. Also provided is a method comprising applying to a vagus nerve of a subject a current that reduces heart rate variability of the subject.

Abstract: A method is provided for treating a subject, including applying a current to a site of the subject selected from the list 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.

Abstract: A method is provided for treating a subject, including applying a current to a site of the subject selected from the list 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.

Abstract: Apparatus is provided for application to a nerve of a subject, the apparatus comprising an electrode device, which comprises a housing, which is configured to be placed at least partially around the nerve, so as to define an outer surface of the electrode device and an inner surface that faces the nerve. The electrode device further comprises one or more first electrode contact surfaces, fixed to the inner surface of the housing, and one or more second electrode contact surfaces, fixed to the outer surface of the housing. Other embodiments are also described.

Abstract: Apparatus is provided for application to a nerve of a subject, including a housing, which is configured to be placed at least partially around the nerve so as to define an inner surface of the housing that faces the nerve. A plurality of insulating elements are coupled to the inner surface of the housing at respective insulating element longitudinal positions along the housing, such that the inner surface of the housing and pairs of the insulating elements define one or more respective cavities at respective cavity longitudinal positions along the housing. One or more electrodes are fixed to the housing in fewer than all of the cavities. Other embodiments are also described.

Abstract: Apparatus is provided including an electrode device, adapted to be coupled to a site of a subject; and a control unit, adapted to drive the electrode device to apply a current to the site intermittently during alternating “on” and “off” periods, each of the “on” periods having an “on” duration equal to between 1 and 10 seconds, and each of the “off” periods having an “off” duration equal to at least 50% of the “on” duration. Other embodiments are also described.

Abstract: Apparatus is provided for applying current to a nerve, including a housing that is adapted to be placed in a vicinity of the nerve. First, second, and third electrodes are fixed to the housing at first, second, and third longitudinal sites of the housing, respectively. The first, second, and third electrodes do not come in direct physical contact with the nerve. The second site is between the first and third sites. The second electrode has an electrode surface axial length. The apparatus also includes first and second internal insulating elements, which are fixed to the housing between the first and second longitudinal sites, and between the second and third longitudinal sites, respectively. The first and second internal insulating elements are shaped so as to define, upon placement of the housing, a nerve axial distance between the first and second internal insulating elements that is less than the electrode surface axial length.

Abstract: A method is provided, including implanting in an atrial wall of a subject, from within an atrium, a first electrode contact in a vicinity of a parasympathetic epicardial fat pad of the subject, and implanting a second electrode contact in a body of the subject outside of a heart and a circulatory system. A current is driven between the first and second electrode contacts, and configured to cause parasympathetic activation of the fat pad. Other embodiments are also described.

Abstract: A method is provided for treating a subject, including applying a current to a site of the subject selected from the list 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.