Conventional dual chamber pacemaker V closed loop stimulation

Hello everybody,  I have had a conventional dual chamber Boston pacemaker for 14 years and am due a change, I have been listed for a Biotronik closed loop stimulation pacemaker, if anybody would like to share their experiences of CLS it would be appreciated, I have read some things online but there is no doubt lots I still don't know, I'm just used to a low setting (of 50) for bradycardia but it sounds like there is an upper limit too? I exercise regularly, weights and cardio, at least four times a week, could this upper limit and whatever the CLS does at that point affect me? Don't understand the point of that part of it. The research says that the CLS reduces Vasovagal syncope, in 14 years I have only ever had 1 actual fainting episode during which my pacemaker didn't work, multiple occurrences were it did and I knew it was working at the time, what are other people's experiences in terms of fainting regardless of your pacemaker, and if the CLS has made a difference to that over the conventional dual chamber 



CLS and upper limit

by AgentX86 - 2020-01-12 20:45:35

AFAIK, CLS taps into the vagal nervous system help set the heart rate with feedback (the closed loop part) from the autonomic nervous system.  The pacemaker may or may not use an accelerometer for rate control, as well.  The idea is to more closely match the heart rate to the body's needs than can be done with an open loop system (accelerometer or minute ventilation).  It's my understanding that unlike the open-loop systems, the CLS system can increase heart rate due to stress (fight or flight). All of these systems are rate adaptive means for those with chronotropic incompetence.

In either case, the pacemaker has to protect the heart against the pacemaker driving the heart into tachycardia. The upper limit is there to keep the heart from going faster than your EP thinks is safe for you.  If you hit that limit with exercise, it'll show in your interrogation report and you can negotiate a higher limit with your EP.  It is there as a protection measure, though, and you may be in for a fight. 


by arentas80 - 2020-01-31 22:23:43

Hi there!

I have a Biotronik PM installed 12/30. The EP's turned on the CLS setting and it was NOT for me. The very next day I went for a simple walk and my heart rate spiked from like 95 to 140 in like a second. I felt like I was going to faint. Anyhow I couldn't get an Appt for a few days so I had to live with these CLS induced tachycardia episodes 5 or 6 times a day for like 4 days. I was brushing my teeth and my HR jumped to 140. I walked to the restroom, HR jumped to 140. The silliest things would trigger it. Anyhow they turned mine off and it's never happened again. Make sure you need this setting or else it may cause you some issues. 

All the best,


CLS Biotronik

by 99becks - 2020-03-01 12:51:51

So I had my CLS Biotronik fitted three days ago, it sounds like I am having similar episodes to you arentas80, already today I've had five or six episodes of tachycardia in the last couple of hours up to 140/minute for no reason at all, I'm just sat or lying down at the time, think I need to contact clinic tomorrow to arrange to go in and have it checked because something doesn't feel right, I never experienced this with my closed loop PM, still got quite a lot of pain too with intermittent stabbing type sensations around the site and near my shoulder / armpit 

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