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 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: 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.

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, 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, configured 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 when the housing is placed in the vicinity of 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 such that the at least one electrode is between the end insulating elements, and the end insulating elements come in contact or practically in contact with the nerve when the housing is placed in the vicinity of the nerve. 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: Apparatus for treating a subject suffering from spontaneous atrial fibrillation includes an electrode device, adapted to be coupled to a vagus nerve of the subject, and a control unit, adapted to drive the electrode device to apply an electrical current to the vagus nerve, 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: 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 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: Apparatus is provided for treating a condition of a subject, including an electrode device, adapted to be coupled to an autonomic nerve of the subject, and a control unit. The control unit is adapted to drive the electrode device to apply to the nerve a stimulating current, which is capable of inducing action potentials in a therapeutic direction in a first set and a second set of nerve fibers of the nerve, and to drive the electrode device to apply to the nerve an inhibiting current, which is capable of inhibiting the induced action potentials traveling in the therapeutic direction in the second set of nerve fibers, the nerve fibers in the second set having generally larger diameters than the nerve fibers in the first set. 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 (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 for treating a subject suffering from spontaneous atrial fibrillation includes an electrode device, adapted to be coupled to a vagus nerve of the subject, and a control unit, adapted to drive the electrode device to apply an electrical current to the vagus nerve, 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.