Implantable Neurostimulator Treats Central Sleep Apnea

A next-generation implantable system delivers electrical pulses to one of the phrenic nerves, which send signals to the diaphragm, restoring a more normal breathing pattern during sleep.

The ZOLL Medical Corporation (ZOLL; Chelmsford, MA, USA) remedē EL-X system is designed to provide transvenous phrenic nerve stimulation to the left pericardiophrenic or right brachiocephalic vein in order to provide neurostimulation to the adjacent phrenic nerve, resulting in diaphragmatic contractions during sleep. A more stabilized gas exchange and improved breathing pattern is thus established, resulting in fewer apneic events, improved oxygen saturation, and increased end-tidal carbon dioxide (etCO2).


The system includes the battery-powered pulse generator, implanted subcutaneously in the upper chest and an external system programmer. The new remedē EL-X model delivers extended longevity, reduced size, and an enhanced suite of diagnostics compared to the previous model, with 40% longer battery life, a simplified single-lead, single-port system that provides both stimulation and sensing from a single lead, and new data-driven clinical insights view DRēAM View, a software suite that includes full-night, comprehensive diagnostic capabilities.

“The next-generation remedē System is built on the proven success of the current platform, with the needs of both patients and clinicians in mind,” said Pete Sommerness, President of ZOLL Respicardia. “The increased longevity, smaller size, enhanced diagnostics, and simplified implant procedure will substantially benefit patients.”

There are two primary classifications of sleep apnea, obstructive sleep apnea (OSA) and CSA. OSA results from a blockage of the upper airway; CSA occurs when the brain fails to send appropriate signals to the breathing muscles that stimulate a regular breathing pattern. CSA symptoms include chronic fatigue, excessive daytime sleepiness, cognitive impairment and inability to get restful sleep. Many patients with CSA also have heart disease, especially heart failure (HF), and are at increased risk for hospitalizations and even death.