pacemaker dependent ?

I have just been for a check up today, to be told that my battery is running low. I have had this pacemaker for 3 years and I am shocked, my 1st pacemaker lasted 7 years.

It is documented in my medical notes that I am NOT pacemaker dependent yet today I was told my battery is running low becuse I am using it 99% of the time, does that mean I am pacemaker dependent now?
If I am not pacemaker dependent why is my heart using the pacemaker 99% of the time?
Can a person switch from non pacemaker dependent to pacemaker dependent? what can cause this?



Dependant or not?

by heckboy - 2008-01-31 10:01:41


I pace most of the time too, but am not PM dependent. If it went away tomorrow, I wouldn't drop dead, but my pulse would drop down to my resting rate and stay there, no matter what my activity level.

My first PM only lasted 3 years too because the ventricle lead had become slightly dislodged after about a year. The voltage had to be turned up to compensate for what was leaking away.

PM Dependent & Battery Life

by SMITTY - 2008-01-31 11:01:51

Hi Sharon,

I'll see if I can answer any of your question. I guess I would have to start by giving my definition of "pacemaker dependent." To me a person that is pacemaker dependent will die shortly if their pacemaker should stop working. Which of course means their PM is working 100% of the time. However, just because a person's pacemaker is working 100% of the time does not necessarily mean that person is PM dependent.

The frequency of operation of a PM depends entirely on the heart's natural PM and the PM settings. Our heart's natural PM sends an impulse to make the heart chambers contract. Our manmade PM monitors the out put from the natural PM and replaces those impulses that were not sent. Now let's say your manmade PM has a low setting of 70 and an upper setting of 120. So long as you natural PM can keep your heart beating in that range the manmade PM does nothing but monitor what is going on each heart beat. However let your natural heart beat drop below 70 and the manmade PM is supposed to take over the function of making your heart beat.

So some of the questions are what is your PM setting and what would your heart rate be without the help of the PM. Most of us get a PM because of bradycardia (heart rate of 60 or below). Without benefit from the manmade PM our heart rate should return to that low heart rate and while you may not feel very spry or may even start to pass out at most inconvenient times, but you will not die.

So in a nutshell, to know if you are PM dependent you need to know what your natural heart rate will be and know what the upper and lower settings are on your PM.

As for what could make the battery on this unit run down in jut three years, whereas the other on lasted seven years, there are many things that could cause this. Below is something on this subject I prepared for one of the members few days ago. Possibly it will answer some of your questions.

Make of pacemaker

Number of leads, (1, 2 or 3)

Pacemaker settings, A low end setting that is 70 or above usually means the pacemaker will assist the heart more often.

Resistance of the leads. This can increase as the leads get older or for any one of several reasons.

Power (Voltage) settings.

Expertise and knowledge of the technicians doing the checkups. One with little experience or little overall knowledge of the intricacies of a pacemaker can establish settings that will increase the drain on the battery thereby shortening its life.

The stability of the health of the person's heart. If the heart’s health deteriorates, then the pacemaker may have to work more often and the setting changed to accommodate these changes.

I’ve had my PM for eight years. The first time I was given an estimated battery life remaining was about eight years and I got this at the end of five years operation. During the sixth year I had some major changes in my medications which resulted in my pacemaker assisting >90% of the time. At the end of the sixth year the estimated remaining battery life was four years, and on my last checkup at 7.5+ year’s operation that was down to 3.3 years. I am eagerly awaiting my next checkup in March to see what the number is now.

This is the reason I get copies of the printouts from my checkups. The technician will give me the current numbers but they are reluctant to discuss how these compare with the last checkup numbers or how the current numbers figure into the entire picture of my PM operation. I take these numbers home and go over them with a fine tooth comb looking for changes. If I se something that is a mystery I can call and ask a specific question. Sometimes I even get an answer to my question.

My suggestion is for anyone to keep up with the battery life degradation and do their own remaining battery life estimating. Your guess will probably be as good as anyone.
When you finish this if you have more questions I'll be happy to try and find an answer for you.

Good luck,



by peter - 2008-02-01 03:02:58

The reason why your battery is running out fast is because you have a demand pacemaker fitted and it is designed to only work when required. Because your requirement is high running most of the time it flattens the battery pretty quick.Its not really working as its designed. You should have a pacemaker that reflects your demand rate fitted next time. Another words a bigger pacemaker with a bigger battery which can take the strain of continuous running. These normally last 6 to 7 years. Cheers Peter

More on battery life

by ElectricFrank - 2008-02-01 11:02:47

Smitty covered most of the issue very completely so will just make a quick comment. Pacing voltage (or more correctly the joules of energy in each pacing pulse) has a large effect on battery life. At the end of 3 years mine was still showing an estimated battery life of 5-6 years. During that time my ventricle voltage was 2.5V and pacing was near 100% Then I had something happen (probably a virus) that caused me to have intermittent loss of pacing. The Medtronic rep considered it an emergency and set the voltage to 5V. A phone check a week later showed the battery estimate to be 1-2 years. After about a month I insisted on having the voltage requirement checked again and we were able to turn it down to 3.3V. Now the battery estimate went back up to 3-5 years. I'm feeling much better again and my latest telephone checkup showed a pacing voltage of 2.5V is again correct, but it can only be changed at an office visit. I intend to again ask for an office visit to set the voltage down and expect to see another increase in battery life.
You can draw your own conclusion about the effect on pacemaker sales and surgical work to leave the voltage turned up. There is some additional safety margin with the higher voltage, but some studies show that it also contributes to deterioration of the electrode site.



by Sharron - 2008-02-04 05:02:08

I would just like to thank you all for your advise/support it has reassured me, alittle! This pacemaker is a St Jude Identy ADx DR 5380, are they known for short battery life?

The only thing now is that I am worried incase it is a damaged lead that is causing the pacemaker to work harder and therefore use battery life.

My leads are the ones put in 10yrs ago ( with 1st pacemaker), wont they have tissue around them or be inbedded to the side of my heart or vein?

As you can tell I worry alot when it get close to replacement time.
Why cant we have a general anaesthetic then the anxiety may not be as high?
Once again thank you


by uvagershwin - 2008-02-07 07:02:53

Well, I don't think that is normal, unless you are VERY active! My PMs are supposed to last about 8 years! Um, you should definatly check these things out, because your PM shouldn't make up it's mind and change like that. I am not 100% dependant, but think I need to be bumped up because I am tired all the time! Good luck and find out more.

I can't thank you all enough!!

by verne8 - 2014-08-12 03:08:11

Since implant---411 days ago--they've had a hard time with capture so my battery was running down faster than they'd expect. HOWEVER, I was rarely pacing. This was true in February (This is now August).

I just had another check up and my pacemaker is pacing nearly all the time. I FREAKED out. The doc tried to tell me that is just what the PM is supposed to do and it's nothing to worry about and they'll just replace the battery when needed. I was so baffled because for the past 6 months I have worked out faithfully every day on an exercise bike for 45 minutes a day. I was so defeated when I left the office until I read this. I think/hope what is happening is that from the exercise my normal resting heart rate has decreased and since my PM is set for a low of 70 it keeps firing depleting the battery.

During the interrogation the dr changed settings that he said would make me dizzy. I never felt a thing. I was totally fine. That, too, makes sense if my regular resting rate is lower. I'd think, but PLEASE correct me if I am wrong, that if I would have gotten dizzy then I really would have been dependent with a heart rate dropping way too low.

I don't understand this all but at least this has helped take away the panic. I suffer BADLY from panic disorder and this has been a MISERABLE morning with this news. SO grateful for you all. Thanks again.. Verne

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As for my pacemaker (almost 7 years old) I like to think of it in the terms of the old Timex commercial - takes a licking and keeps on ticking.