Backup to pacemaker battery life?

Since August 2018 I have had 2 check ups and both times was told I had 9 months left on the current pacemaker battery. In November they went as far as to tell me that I would be called in for a replacement either just before Christmas or in the New Year. Beginning of December I rang as I had not heard anything and was told another checkup was scheduled for end of January and "not to worry as the pacemaker has a guaranteed back up of 3 more months when the battery ends". I rang again this week to be told I was not on the list for a checkup but to come in anyway and "not to worry a the pacemaker has a guaranteed back up of 4 more months when the battery ends". Is it true that it has its own 'generator'  I am not filled with confidence..



Battery 'backup'

by LondonAndy - 2019-01-24 21:58:39

I think they are wrong to use the word 'backup', and really mean that, much like the fuel gauge for a car, when the needle is pointing to zero there is actually still a 'reserve tank' left.  So there is not some other power source, just a bit more left in the battery than the warning indicator shows

go anyway

by Tracey_E - 2019-01-24 22:44:48

That is somewhat accurate. When they test, the pacer tells them when it is the pacer equivalent of the gas light coming on in a car- Elective Replacement. ERI lasts approximately 3 months, and during that time it works normally. After that, it has another mode called End of Service. When it switches to EOS, it cuts back to minimal function so we are safe but if we pace a lot we will feel like crud. This also lasts approximately 3 months. So, total of 6 months from the time it switches mode until it stops altogether. 

9 months is an estimate. It could be 6 months, it could be a year or more. Only way to know for sure is to have it checked so be insistent about appointments if you know you are close. My last one said 6 months in August. I went again in Nov and it said 3 months. I went in Jan and it had switched to ERI the week after the Nov appointment. When I called to schedule surgery, the nurse wasn't in any rush to get me in because she thought I wasn't ERI yet so I had to point out to her I was already 2 months into ERI so no way was I waiting for anything! I'm dependent so I don't want to mess around and find out what EOS feels like. Long way of saying, don't trust them with the numbers. Push for an appointment asap to find out what's going on, but don't sweat it either, it's not going to just stop. 


Battery Life

by Selwyn - 2019-01-25 08:18:43

Estimation of battery life is an inexact science.

It is based on capacity of the battery/ current drain. Current drain depends on the pacing thresholds, the duration, the amount and type of pacing. 

End of battery life varies with the type of battery.

My battery life is given on my print out in months- years. The reason for the wide variation is that one of my leads has a high impedence and needs more electicity to reach a venticular pacing threshold. Luckily for me the ventricular lead is used <1% of the time ( though it is an important 1%!), hence the wide variation of predicted battery life ( presently up to 9 years, I think). Because of the wide variation I am on 6 monthly checks. In general the TREND is important, ie. the rate of battery drainage is likely to be constant  ( unless you develop a further complication).

The fact that your battery life has not changed between check ups is reassuring, though you don't state how long between the check ups were!

Ideal replacement time is BEFORE pacemaker functions go into their staged decline ( as Tracey_E outlines). Battery voltage will be dropping and the battery impedance rising.

Time for replacement

by zawodniak2 - 2019-01-26 13:46:30

When my pacemaker went into “end of service “ mode, my heart rate stayed at  65 bpm at rest and during activity and like Tracey said I felt like crud. I used a finger pulse oximeter which I highly recommend for all pacemaker recipients.  I am 99.9% dependent and my pacer is set at 60 bpm.   With the pulse oximeter you can monitor your heart ❤️ rate full time to see if your device has gone into eos mode.  


Battery expiring

by Onlyme - 2019-01-26 17:53:49

Thanks everyone, your comments all make sense and I will push for a renewal date. Feeling like crud will be bad enough but what if it causes me to crash whilst driving etc? Not impressed with them playing this down  Check ups were Aug and Nov. 


by Tracey_E - 2019-01-28 10:26:17

when it's in EOS it will pace at a steady 60bpm so driving should be safe enough. Our rate won't dip, but it won't go up on exertion, in this mode. 

Battery expiring

by Onlyme - 2019-02-06 02:45:15

Well they listened and today I'm having battery #4 fitted! Wish me luck  

dont trust the estimate

by dwelch - 2019-02-12 06:19:19

As my ep says ignore the estimate until the esimate says something like 3 weeks. 

Note Insurance companies are staritng to insist that they cannot replace the device until it goes into one of these modes.  In part they dont like docs scheduling replacements too early.  They are no doubt doing the math all the pacers all the patients each getting a device some number of months early, how many millions of dollars lost, etc etc.


I have had at least two go into one of these modes, my first doc didnt have the phone boxes (over 20 years ago), i switched from a visit every year to twice a year as we got close and one of those was a..."hmm, so what are you doign next week"...."you are getting a new pacemaker"...

Honestly didnt know (in both cases) until the doc said something and scheduled the surgery then I started to notice.  Being locked at 65bpm you can drive and things like that but I couldnt climb the stairs at work, had to keep stopping very strange when your heart wont change rate.  used the elevator for a few weeks, new pacer back to normal.  Third pacer replacement checkups were cheaper, doc paid for the checkups insurance wouldnt, got a phone check every month, in office every 6.  Had plenty of warning when it was time.


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