What effect does applying a magnet to an ICD have?

Applying a magnet to an implantable cardioverter-defibrillator (ICD) temporarily suspends tachyarrhythmia detection, which means that the device will not recognize tachyarrhythmias or deliver shocks for a certain period of time while the magnet is in proximity to the device. This feature is commonly utilized in clinical situations, such as during an examination or when assessing the device function, allowing healthcare providers to manage the patient effectively without the risk of the ICD delivering shocks.

This temporary suspension is particularly useful in managing patients who may not need immediate defibrillation or where the shock might cause harm, ensuring safety and control during the assessment or in a medical setting. Once the magnet is removed, the device returns to its normal detection and shock delivery function, resuming its standard programmed settings.

The other choices indicate effects that do not occur with magnet application. For example, using a magnet does not cause any permanent changes to device programming, nor does it shut down the device completely or increase the heart rate. This reinforces the understanding of how magnets interact with ICDs and underscores their role in clinical practice.