White noise

electrical signal noise

by Persephone - 2022-05-26 21:18:00

Hi Blond - I hope you're feeling well. Could you discern if the nurse was speaking of an in-person PM reading or a reading transmitted remotely from your home? Either way, I think you should pursue this comment further with your medical team.

Noise

by AgentX86 - 2022-05-26 21:23:12

White noise is a scientific/engineering term to descibe noise that is constant in amplitude with frequency.  There are other noise "colors", pink, red, blue, black...  The two most common we talk about are white and pink. I know i've said nothing interesting or comprehensible but I just wanted to point out that this term isn't just two $.10 words glued together so they can charge $.50. Well, it is because the "white" part could be left out without the loss of information.

The color of the noise can give a hint to its source.  White noise is "thermal noise".  It's caused by the "movement" of electrons due to temperature.  The higher the temperature, the more the electrons move.  Movement of electrons is current.  Current across a resistor is voltage. Here's where we come out of the weeds.  Since it's a voltage across a resistor (temperature inside your heart is constant) this noise tells us the impedance (resistance) of the leads. If the noise is large, so is the lead impedance. 

This noise may be sensed by the pacemaker as a heartbeat causing an "oversense".  The pacemaker has erroneously detected a signal so doesn't supply one at the right time (inhibits), and a beat is lost.   Obviously, this isn't a good situation, particularly if it's regularly (noise is noise, unpredictable by definition) above the sensing threshold. This threshold can be raised but only far enough so that the real signal can get through.

The long-term solution is a new lead but, as noted above, in the short term the sensing threshold can be increased.  If that doesn't work, one of the asynchronous pacing modes can be used until the lead can be replaced.

Are you sorry you asked yet?  ;-)

old leads

by Tracey_E - 2022-05-27 11:50:07

I've got old leads also. They keep an eye on the noise. Just because there is noise doesn't mean it needs replaced yet, it just means it's not working like new and they are watching it. This is to be expected if it's 20 years old. The doctor will be in a better position to make that call than the nurse. 

Noise

by JaneJ - 2022-05-28 12:07:27

I had noise on my pacemaker when one of my leads was fractured.  It would increase when I would move that left arm also.  As agentx86 had said, this causes the pacemaker to think that the noise is your own heartbeat and therefore the pacemaker will not send out an impulse to make your heartbeat.  The doctors  had kind of a hard time figuring this out for some reason...they finally ended up seeing this by doing a holter monitor that I took home and wore.  Then they saw the noise and that I was having long periods of no ventricular rhythm on the holter monitor.  Scary stuff...noise is definitely noise is something you want to have looked at carefully.  Best of luck, I hope you are able to get things resolved.