Rate Response change?

I am wondering if anyone has ever heard of a situation similar to mine. I have had Boston Scientific Accolade since May '21 after fracturing a lead with my Medtronic.  I am a swimmer and my EP and I thought I would get a better rate response for that activity with the dual sensor.  That turned out not to be the case and we concluded that only the accelerometer was effive in the pool, and that wasn't great.  I was learning to live with it.  About 3-4 weeks ago, I noticed a significant change.  I am very uncomfortable in the water and it feels almost like it did when I broke my wire.  My HR gets to the 70s-80s.  Prior to getting the BS I would get to 108ish and with it I would get to 96ish. The difference is that I do not feel like this with other activities, jogging, biking, hiking etc.  I can go to 130 which is my upper limit. 

They had me come into the office and made some adjustments.  They do not seem to be helping significantly.  The pool is about the same.  My EP says he has no further suggestions.  I really like this guy but am frustrated with this response.  They do not seem to be hearling me that something CHANGED!  I feel like the accelerometer function is not working well.  In land based activity, my breathing gets heavier and faster so I think the MV part is kicking in. If it's not the device, then it's me.  I am written to BS but no response yet.  

I would welcome any insight.

Jeff Wren

Age 73



I would welcome any feeedback




by Lavender - 2022-11-02 11:08:07

I read about closed loop stimulation in this informational article from the US masters swim site. Don't know if your device has this feature though.

"It’s called CLS, for “closed loop stimulation,” and unlike accelerometers that key in on physical movement, this technology functions as a miniaturized EKG capable of sensing how hard the heart itself is squeezing. “Whether your heart muscle is squeezing harder because of exercise, stress, anger, or anything else that excites the heart,” Hofmann Bowman says, “this technology detects increased impedance and tells your heart to beat faster to meet increased demand.”

Have to copy and paste it:


Can different brand of PM Generators be interchanged?

by brady - 2022-11-02 12:14:00

Sorry to hear the BS that you have does not work well for swimming and you think it could be due to different breathing pattern for different activities. 

Not knowledgeable to answer your question, but just curious are the different brand pacemaker generators interchangeable? 

You need your PM reports

by crustyg - 2022-11-02 13:12:15

Which most civilised countries allow you to get from your healthcare providers - against their will, if necessary.

I can think of various reasons why things might have changed for you, and probably the quickest way to prove it to your EP-doc is to ask/demand a Bruce Protocol treadmill test.

Armed with that information you will be better able to plan any necessary changes with your EP-doc.

PM leads are standardized

by brady - 2022-11-02 18:15:46

If one has Medicare, he does not need to demand the EP for a Bruce Protocol treadmill test. All one needs is for the cardiologist agrees to offer the test.

I checked the internet, it seems that all the pm leads are standardized. If all else fails, changing    The PM to the previous brand is an option to consider.

"Standardization of pacemaker and defibrillator leads has allowed for global compatibility across manufacturers of cardiac implantable electrical devices (CIEDs). For example, a physician can implant a pacing lead from one company that has an international standard-1 (IS-1) terminal ring and pin arrangement, and connect it to a pacemaker generator from another manufacturer as long as it has an IS-1 type receptacle in the header. This has permitted the flexibility that is occasionally needed when trying to provide the best system for an individual patient, particularly at the time of a system revision. A recent new standard is the DF-4 lead that allows implantation of any company’s quadripolar in-line defibrillator lead to a different company’s defibrillator generator. "



by ourswimmer - 2022-11-02 23:37:41

As far as I know, CLS is Biotronik's proprietary rate response system. As a fellow swimmer, I'm sorry to JWren that I have no other insight to offer.

Something is up

by PacedNRunning - 2022-11-07 16:39:55

HI. We know when things aren't the same with these devices. Something has changed.  Ask them to reset your MV sensor. Also see if you can do a magnet recording during swimming to capture what is going on. I know my MV sensor would turn off randomly if it detected noise with exercise.  They may need to switch the lead vector if it keeps doing that. If they won't give you a magnet, go swim and then go for a device check that day, they can see exactly what your PM did while swimming. 

You know you're wired when...

You can feel your fingers and toes again.

Member Quotes

I just want to share about the quality of life after my pacemaker, and hopefully increase awareness that lifestyles do not have to be drastically modified just because we are pacemaker recipients.