Bradycardia due to a neuro device

A young patient came in due to seizure. What is happening here? Is there a device malfunction?

Figure 1

No wires are going to any chamber. Instead, the device was a vagus nerve stimulator (VNS).  This is the tracing (Figure 1) when the device was being adjusted for the optimal output until no bradyarrhythmic events were noted.

Figure 2

Patient had this device (VNS) for a number of years. During this admission, bradyarrhythmic events  (Figure 2) were noted. Device behavior was observed. No bradycardic events were noted when device was off but had several bradycardic events when it was turned on (~ 3 seconds - not shown here) So, neurology service had to adjust the output.

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