Closed Loop vs. Rate Response

So in my 3-1/2 months of having a Pacer due to Bradycardia, I have been on a roller coaster with settings. I'm pretty sure that I was originally set on Closed Loop and was moved to Rate Response in early February when I was zapped out of an Afib event (Which I'm positive the Pacer triggered). When on the Closed Loop setting, the Pacer hits the Ventrical lead at random times and tachys me to 120... Always 120, and always a little random! When on the Rate Response setting, it was too sensitive as I'm 47 and very active and would shoot me up due to feeling the vibration of me walking, or riding in a rough riding car, or whatever would make my body vibrate... Probably 100 times a day, and again always exactly 120. So I had them change it back a couple of weeks back (The Biotronic rep recommended Closed Loop beacause of my age and activity level, but it's so random), and now I remember how irritating the Closed Loop is (Granted 20 times a day is better than 100). But, back to random rate increases, and still always 120. Opposite of Rate Response, it'll wait until I stop walking or sit down. It will do it when I stand up too quickly or roll over quickly in bed (What sent me into Afib in February). It will occasionally wake me up doing it in the middle of the night. It will do it when I bend over quickly, or just pull my knees to my chest (Like it senses internal pressure). Suddenly today, after an early episode when I got out of bed, it decided to stop... altogether. Not one episode since 5:30 this morning. However what I noticed while at work is that I was a little short of breath a few times when briskly walking the halls at my job. Like I needed it to come up, but my untreated Bradycardia doesn't allow me to get much over 70 under those circumstances. Again, frustrating.

So, a couple of questions... Why, regardless of setting does it take me to 120? It's a steep increase, and the feeling is like when you're at a device check and they raise you with the computer. You feel it doing it at the bottom of your heart and after 10-15 seconds it feels like it's trying to take your breath away a bit. If it's a setting set at 120, can they go back to Rate Response and move it to 80 or 85 and not have it set so sensitive? And if they do lower the setting, will I still feel it the way I do now when It's kicking it up? Hopefully someone has experienced similar things and might have insight...

2 Comments

Closed Loop vs. Rate Response

by bens83@gmail.com - 2017-05-13 07:07:56

Hi there,

I'm a pacemaker technician with about 10 yrs of experience with your model of pacemaker. This sounds like it could be one (maybe two) of three things, but I will need more info about the type of pacemaker that you have. Is it a single chamber pacemaker (Eluna SR-T/Etrinsa SR-T/Entovis SR-T/Evia SR-T) or a dual chamber pacemaker (Eluna DR-T/Etrinsa DR-T/Entovis DR-T/Evia DR-T)?
My first thought is that they have your "rate response" incorrectly programmed. Your device has both an "accelerometer" (if programmed DDDR or VVIR)  and "Closed Loop Stimulation" (if programmed DDD-CLS or VVI-CLS). If programmed DDDR or VVIR it's possible they have the accelerometer "sensor gain" set too high (i.e. High, Very high, or even AUTO -*more on this later*) and/or your "sensor threshold" is set too low (i.e. very low or low). What this means is that any small, sudden movements will tell your pacemaker to ramp up your heart rate to your maximum sensor rate (i.e. 120 bpm) very quickly. This could explain why your heart rate suddenly goes to 120 when you briskly walk down the hall or turn over in bed. If "sensor gain" is set to AUTO (which is out of the box setting and unlikely changed) the pacemaker watches for your average daily activity, and if you have a few days of sedentary activity the AUTO setting tells the pacemaker to become more and more sensitive to motion and more easily activates the rate response of the pacemaker.

Secondly, if instead they have it programmed to use Closed Loop Stimulation (DDD-CLS or VVI-CLS) they may have the "CLS Resting Rate Control" set to (OFF, or +40, +50 bpm). This essentially turns off the pacemakers governor and let's it immediatley ramp your heart rate up to the upper sensor rate (i.e. 120 bpm). This type of programming is commonly used to treat Vasovagal Syncope (VVS). By turning off the governor of the pacemakers rate response it allows the pacemaker to suddenly spike your heart rate (up to the programmed maximum sensor rate i.e.120 bpm if set that way) when CLS detects the blood pressure suddenly drops. This is how CLS treats VVS and keeps you from passing out.  

Lastly, if you have a dual chamber pacemaker you could be experiencing PMT (pacemaker mediated tachycardia). This can easily be fixed with a programming change (PVARP setting). 

I hope this helps!

BTS

 

Check Up Today

by CrockerNut - 2017-07-05 15:33:48

Thanks BTS,

Sorry I didn't respond sooner, things have been hectic with other issues (surgery) on the head. I am going in again today for a check up and device check. I appreciate the information you gave and hopefully they are willing to check the settings a little closer.

As for my device... It is an Eluna 8 DR-T dual chamber.

If you don't mind I'm going to ask the tech to give me a printout of the settings after today's appointment and share it with you. I'm beginning to lose confidence here, but because we're in a small town options are limited. If they can't get me to where I'm comfortable enough to get back to exercising fulls peed then I'm probably going to seek options in Portland (3.5 hours away). But before it comes to that, hopefully you don't mind me picking your brain once or twice more.

You know you're wired when...

You trust technology more than your heart.

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