Obstructive sleep apnea (OSA) affects millions of people, and alternative treatments are necessary for those who cannot tolerate Continuous Positive Airway Pressure (CPAP). Inspire therapy, an implanted device, has emerged as a successful option for managing OSA, but many patients also have other implanted electronics, such as pacemakers. Since both devices rely on electrical signals, patients with pre-existing cardiac devices often question the safety and compatibility of receiving an Inspire implant. Having a cardiac device does not automatically disqualify a patient from receiving Inspire, but it requires careful medical coordination.
Understanding Inspire and Cardiac Implants
Inspire therapy, also known as hypoglossal nerve stimulation, is an implanted system designed to treat moderate to severe OSA. The system consists of a neurostimulator battery placed in the chest, a breathing sensor lead, and a stimulation lead targeting the hypoglossal nerve. This nerve controls the tongue muscles. The system monitors breathing patterns and delivers mild electrical pulses during sleep, causing the tongue to move forward and keep the airway open.
Pacemakers (PPM) and Implantable Cardioverter-Defibrillators (ICDs) are also battery-powered electrical devices implanted in the chest to manage heart rhythm disorders. A pacemaker delivers low-energy electrical pulses to regulate a slow or irregular heartbeat. An ICD performs the same pacing function but can also deliver a high-energy shock to correct dangerously fast heart rhythms. The core similarity between Inspire and these cardiac devices is their reliance on electrical signals, which creates a potential for interaction.
The Risk of Electrical Interference
The primary concern when implanting two electrical devices is Electromagnetic Interference (EMI). The mild electrical pulses emitted by the Inspire system could be misinterpreted as a natural heart rhythm signal by the sensing circuitry of a pacemaker or ICD. This misinterpretation is known as “oversensing.”
If the cardiac device oversenses the Inspire pulse, it may react inappropriately. For a pacemaker, this could cause the device to temporarily stop pacing the heart, a phenomenon called inhibition. Inhibition can be dangerous for patients who rely on the device to maintain a consistent heart rate. For an ICD, oversensing could lead the device to incorrectly identify the Inspire pulse as a life-threatening arrhythmia, resulting in the delivery of an unnecessary, painful shock.
While this risk exists, it is manageable and minimized by modern device design and careful surgical planning. The risk of interaction is higher for an ICD than for a standard pacemaker, as ICDs are often programmed to be more sensitive to detect subtle arrhythmias. The electrical fields generated by the Inspire device can affect the ability of the cardiac device to sense and respond to the heart’s function as intended. Pre-planning is an absolute necessity for patient safety.
Safety Screening and Device Management
Before a patient with an existing cardiac device can receive Inspire therapy, a comprehensive safety screening is mandatory. This involves close coordination between the sleep specialist and a cardiologist. The process begins with a detailed pre-operative discussion to plan the implantation strategy and discuss possible interactions. To minimize the chance of EMI, the Inspire generator is typically placed on the opposite side of the body from the cardiac device, ensuring a minimum separation of at least six inches.
Management During Implantation
During the Inspire implantation procedure, the cardiac device requires specialized management to prevent interference from surgical tools and the new implant itself. A cardiac device specialist will interrogate the pacemaker or ICD, often temporarily reprogramming its settings, such as changing the sensing mode, to ensure patient safety. After the Inspire system is implanted, the cardiac device is re-interrogated and tested at various Inspire stimulation settings to confirm that no oversensing or interference occurs.
Post-Activation Follow-up
Compatibility testing continues into the post-activation period. Ongoing follow-up checks by both the sleep specialist and the cardiologist are necessary to ensure the devices remain compatible as the Inspire therapy is activated and adjusted to its therapeutic level. This careful, multidisciplinary approach allows patients with pacemakers or ICDs to safely pursue Inspire therapy.