Sudden cardiac arrest is a life-threatening emergency requiring immediate action. Confusion over using an Automated External Defibrillator (AED) on a person with an implanted cardiac device is common, but treatment should never be delayed. External defibrillation is a time-sensitive procedure that offers the best chance of survival. This article provides clear guidance on the necessity and proper technique for using an AED on someone with an internal cardiac device.
Understanding Implanted Cardioverter-Defibrillators and Pacemakers
An Implantable Cardioverter-Defibrillator (ICD) is a small, battery-powered device designed to monitor heart rhythm continuously. Its primary function is to detect dangerous, rapid heart rhythms, such as ventricular fibrillation, and deliver an internal electrical shock to restore a normal heartbeat. Many modern ICDs also have pacemaker capabilities, meaning they can deliver low-energy electrical pulses to keep the heart from beating too slowly.
A standard pacemaker focuses on treating heart rhythms that are too slow or irregular. It primarily uses low-energy electrical impulses to ensure the heart maintains a steady pace. Unlike an ICD, a traditional pacemaker cannot deliver the high-energy shock needed to correct a life-threatening, chaotic rhythm like ventricular fibrillation.
Safety and Necessity of Using an AED
If a person with an implanted device collapses, is unresponsive, and is not breathing normally, the immediate use of an AED is required. Resuscitation guidelines state that the potential benefit of external defibrillation far outweighs any minimal risk to the implanted device. The AED is designed to treat sudden cardiac arrest, a condition that can occur even if the internal ICD has failed to correct the rhythm or if the patient has a pacemaker without defibrillator capabilities.
Time is the most significant factor in survival; every minute defibrillation is delayed reduces the chance of survival by approximately 10%. If the implanted device has recently delivered a shock, the patient’s muscles may contract. If the patient remains unresponsive, the AED should still be used immediately, as the benefit outweighs the risk of waiting for the internal device to complete its cycle.
While the external shock could temporarily disrupt or damage the implanted device, saving the patient’s life is the primary concern. The AED’s analysis function assesses the heart’s electrical activity and delivers a shock only if a life-threatening rhythm is detected. Follow the AED’s voice prompts and deliver the shock when advised; the internal device can be checked and reprogrammed by a medical professional later.
Specific Placement Guidelines for AED Pads
The primary physical consideration when using an AED on a patient with an implanted device is to avoid placing the external pad directly over the device itself. Implanted devices, which are commonly located just under the skin near the collarbone on the left or right side of the chest, appear as a small bulge with a scar. Placing an AED pad directly on this lump could potentially divert the electrical energy, making the shock ineffective, or cause damage to the internal device.
Rescuers should locate the device and ensure the AED pads are placed at least one inch away from the generator. The standard pad placement is typically one pad on the upper right side of the chest below the collarbone and the other on the side of the left rib cage, below the armpit. If the implanted device is in the path of the standard placement, an alternative technique must be used.
An alternative method is anterior-posterior placement, where one pad is placed on the center of the chest and the other is placed on the back, between the shoulder blades. This configuration ensures the electrical current passes effectively through the heart while completely avoiding the area of the implanted device. Additionally, if the patient has a wet chest or a medication patch in the area, the chest should be dried or the patch removed and the skin wiped before applying the pads to ensure proper electrical conduction.