CLS mode on pacemaker engaged.

Closed Loop Stimulation Mode

by Gemita - 2024-09-13 19:14:20

Jules, hello and welcome.  Looking at your Bio, I do not believe the symptoms you are currently describing can all be attributed to the Closed Loop Stimulation (CLS) mode, particularly since you have such a complex medical history, but perhaps I am mistaken?

With regards to your current symptoms, do you really feel they were caused by engaging the CLS  system - a special rate response mode - on your Biotronik pacemaker?   From members here, I know they have always said that the CLS can be difficult to manage and that it takes time to adjust the settings to suit the patient.  I have also seen that some members had to get CLS turned off because they were getting tachycardia due to the system over responding with high rates from minimal exertion.  CLS also apparently responds to mental/emotional stress.

We have a few members here with the same pacemaker and I hope they will see your post and respond with their personal experiences.  

I would be particularly concerned about the weight loss which would be a red flag for me.  This should be reported to your doctors.  The chest pain and vision disturbances if new, need further assessment too.

Hope the following links are helpful on CLS.  The second link is a more recent Pacemaker Club discussion on the CLS system.  Both links should be copied and pasted into your browser to open:-

https://www.pacemakerclub.com/message/10738/experiences-with-closed-loop-stimulation

https://www.pacemakerclub.com/message/43514/biotronik-cls-algorithm-causing-problem

Closed loop

by piglet22 - 2024-09-14 06:22:39

I had to look up CLS.

Closed loop, or feedback, the term I'm familiar with, is a system where an output is required to remain constant, despite other things influencing that output, changing.

A purely mechanical example is the governor on a steam engine which maintains a constant speed of say, a shaft, despite the load on the shaft varying, perhaps a locomotive going from level to climbing an incline. The cruise control in a vehicle is exactly the same.

Another example is an electric motor that needs to run at a set speed, say 1000 RPM. The motor has a speed measuring device, a tachometer or rev counter. If the speed drops to 900 RPM, the system, the controller, increases the power to the motor to bring the speed back to 1000 RPM.

In practice, this happens continuously.

However, it can go wrong. If in the motor example, using an optical tachometer, dust gets on the sensor from the process using the electric motor, the controller tries to increase the motor speed, thus increasing the dust. This goes on until the motor blows up. This is called positive feedback. There are other systems that work as negative feedback.

I would imagine in the pacemaker system, an output, cardiac output, is set and sensors in the device feedback information to the controller/processor to increase or decrease the output. If something happens and part of that control loop goes faulty, the output behaves unexpectedly.

This is a danger of feedback.

On the global scale, climate change or global warming, we are seeing feedback in action.

Ice caps and glaciers start to melt. Instead of reflecting back heat from the sun, the exposed rock or soil in the case of tundra, absorbs heat, thus increasing the rate of melting. This carries on until all the ice has melted, sea levels rise, seawater becomes warmer and less saline. This upsets the delicate atmosphere - oceans balance.

As Gemita says, CLS is a form of Rate Response. Where CLS might differ is that Rate Response doesn’t have the sophisticated feedback element. It’s like saying the room is cold, turn up the heating. That’s the response. The feedback is the thermometer saying I’m warm enough, turn the heating off.

JULIACOLACE

I can see you have a lot going on.

The last hing you need are problems with a pacemaker. You need to be swiftly brought into the care of your team and get reassurance from being thoroughly checked over.

I've no doubt your team are aware of the effects your complex case might have.

Good luck with all that.