LAUSR

Key Teaching Points • Late-onset asystole is a rare but significant complication in patients with a vagal nerve stimulator of which the clinician needs to be aware. A good clinical suspicion, thorough history, and physical examination are key to help discern cardiac vs neurogenic causes of syncope. • Autonomic neural input to the heart exhibits some “sidedness,” with the left vagal nerve having more influence on the atrioventricular node and right vagal nerve having more influence on the sinus node, which is why the stimulator is placed on the left side of the chest. This is thought to be secondary to the embryonic rotation of the body during development. However, it is important to know that there is some degree of overlap between the left and right vagal nerve innervation. • Very few cases of late-onset syncopal events associated with vagal nerve stimulation therapy have been reported that were treated with removal or deactivation of the device. Another approach could be to implant a permanent pacemaker in a patient who would not tolerate removal of the stimulator owing to intractable epilepsy.