Setting changed but don't understand it

by FighterGirlxx
2016-08-19 12:13:00
Checkups & Settings
1567 views
6 comments

so yesterday just before my subcutaneous ICD box was changed I had my pacemaker checked. They changed it to include breath response rate setting max up to 120bpm. This was based on the bar graphs showing distribution - my heart rate sits around 60 (bradycardia) as ppm stops it and not much higher. They said that my heart rate not increasing on activity could be partly why I get short of breath. What I don't understand is why my heart wouldn't be responding appropriately and why I need the rate response. I won't know for a while if it's working as I'm recovering still from surgery.

can anyone explain why my heart wouldn't be responding to exercise appropriately and why I need the rate response?

thank you

6 Comments

Setting Changed

by Good Dog - 2016-08-19 13:07:15

I know very little about rate response. However, it is important to understand that your PM functions to insure that your heart beats properly and in-sync (so that it pumps efficiently and you feel well). Thing is, your heart may not respond appropriately to increased activity. I can't explain exactly why, except to say that our electrical system just doesn't always function as it should. That is a very common problem with us PM patients. In-other-words; if you decide to run around the block a few times, your heart should speed-up to insure your blood is passing more oxygen along to your body as your breathing increases. Your PM will insure your heart beats properly in-sync, but it doesn't know on its own to speed-up your rate (if necessary). Thus the need for rate response. So if your heart doesn't increase its pumping rate as it should, then the rate response needs to be turned-on to increase the rate appropriately.

You are suffering from "Chronotropic Incompetence'

by IAN MC - 2016-08-19 13:22:06

Hi FIGHTERGIRL ; That is the medical term for it and you are not alone. Over half of all people with pacemakers need rate response switching on because their heart rates don't increase sufficiently when they exercise.

Why does this happen ? Usually because the pacemaker you were born with ( your sinus node ), has become faulty and is not sending the right messages to your heart when you exercise . It also deteriorates with age which is why 70 yr olds don't run as fast as 20 yr olds .

I didn't need Rate Response when I first got a PM but after a couple of years found that I did . Electrical problems of the heart have the nasty habit of changing with time.

The human body is very clever and if the sinus node doesn't work properly , or if you have complete heart block there is a lower "escape" pacemaker which responds to exercise . In your case one of these two mechanisms, or both, has become faulty.

The rate response function built into your ICD will have one or two sensors which detect when you exercise and will tell your PM to put in extra heart beats next time you run up a hill so theoretically you should become less breathless. In your case it has been set to put in extra beats until you hit 120 bpm, this is known as your maximum sensor rate. My maximum sensor rate is set at 165 bpm but I am a really avid exerciser.

Rate Response is not quite as good as having a normally functioning sinus node but once you have got the settings optimised to match your requirements you should be fine for most activities.

Best of luck

Ian

IAN MC - THANKS!

by Good Dog - 2016-08-19 15:42:45

Ian,

Thanks for the explanation!

Thank you

by FighterGirlxx - 2016-08-20 16:44:27

Ian MC and GoodDog - thank you both. It makes more sense. I've been struggling with SOBOE so I'm hoping that this ventilation response will help with that. I'm not meant to over exert myself at the moment, hence the 120 setting. By the way - does the 120 setting mean my heart can't go above that?

You are welcome

by Good Dog - 2016-08-20 20:17:00

Your heart can certainly go above the max setting of 120. Although it can, I don't know if it will. The only way to find out is after you have fully recovered you can gradually extend your exercise and monitor your pulse. As long as you feel O.K., you can slowly and carefully push yourself to see what you can handle. I began playing basketball about 4 months after I had my PM implanted. My max setting was 120 and I often took my pulse and found it to be well over 180 bpm. I was much younger then.

So the important thing is to use common sense, but don't allow your ICD to prevent you from living your life the way you choose.

Sincerely,

David