Understanding Pacemaker Discharges: When Do You Feel Your Pacemaker ‘Go Off’?

I have personally experienced a shocking incident that led me to question the function of my pacemaker. On November 7, 2019, I thought I had just been shot in the back, and I experienced a simultaneous flash of light. Thankfully, it was just the discharge from my pacemaker, and since then, nothing similar has happened. However, the sensation was certainly memorable, as I couldn’t have possibly missed it.

Types and Function of Pacemakers

There are different types of pacemakers, and based on your question, it seems you are referring to an Automatic Internal Cardiovascular Defibrillator (AICD). Yes, the shock from an AICD is momentarily felt and will catch your attention. This is a crucial feature since it ensures that the pacemaker works as intended to prevent life-threatening situations. However, it is a small price to pay compared to the alternative—sudden cardiac arrest.

A regular pacing pacemaker, on the other hand, is not felt. It provides a small electrical current to stimulate proper cardiac function, which is often imperceptible to the user. The purpose of a pacemaker is to maintain a consistent heartbeat, and the timing and strength of the electrical pulse are regulated by the device.

Pacemaker Discharges and Thresholds

When we talk about the pacemaker 'going off,' we are usually referring to instances where the pacemaker takes over the pacing function because it has sensed an anomaly in the heart's rhythm. For example, many pacemakers are set to a specific threshold to ensure they only intervene when necessary. If the heart rate drops below this threshold, the pacemaker immediately takes over the pacing. Conversely, if the pulse remains above the set threshold, the pacemaker remains in standby mode.

For one particular instance, my pacemaker was installed to address an abnormally low heart rate. Initially, I could feel the transition from being paced to not paced and from the pacemaker taking over as my pulse decreased. Over time, after about a year, I no longer felt this transition. Modern pacemakers, such as those equipped with an Implanted Cardiovascular Defibrillator (ICD), can not only provide pacing but also shock a heart back into normal sinus rhythm in cases of fibrillation. If an ICD fires, it is certainly a noticeable event, and the sensation can be quite startling.

Conclusion

While a pacemaker discharge may startle you temporarily, it is a critical safety measure to prevent more serious health issues. Understanding the function and purpose of your pacemaker can help alleviate some of the initial fear and worry. If you ever experience concerns about your pacemaker's performance, it is essential to consult with your healthcare provider for further guidance and support.