Battery life towards the end

Battery life is not linear

by crustyg - 2021-02-28 15:58:09

Depending on the specific nature of the battery (they are all chemical these days), the voltage drop-off over time isn't linear as the battery nears the end of its life.

When the PM is interrogated and the estimated battery life is reported this value depends on two things: the vendor's existing knowledge of how their batteries perfom over time, and secondly that the present charge taken for each pacing output remains constant.

Neither of these assumptions is always correct.  Some batteries degrade more quickly over time (although I'm not suggesting that's what is happening here - but you can search for PM early recalls due to battery failures - it happens to vendors sometimes), but the thing most likely to change is the output voltage (+/- the pacing output pulse-width required for capture) per pacing output.  This can change over time as the lead=>heart muscle junction can change, or a lead can develop a charge leak, so requiring more output to maintain pacing capture.

Most standard PMs are predicted to give 6-8years before a change (the larger, bigger battery extended-life models can achieve 12-15years), so 6-6.5 or 7.0 years isn't a major shortening.

My *guess* is that yes, you can expect a continuing decline in predicted battery life.

Make sure that your EP team is on top of this. Be assured that your PM has been designed to keep a pacing output even as the battery nears end-of-life.  It's not going to suddenly conk out on you the way that a torch battery suddenly gives up.

There have been some contributors here who have seen predicted battery life go from 6years to 3years to 1year in about 2years => this is lead failure, or a major issue at the lead=>heart junction.  This isn't you.

battery life

by new to pace.... - 2021-02-28 17:00:15

Since i have been tracking mine via the remote transmissions. that the medtronic rep reads.  Seems that every 3 months i loose 2 months of battery usage.

new to pace

Battery drain

by AgentX86 - 2021-03-01 00:36:11

The readings early in the PM's life are only gross estimates.  As the pacemaker gets closer and closer to end of life (it's not yours ;-) the estimates get better an better.  Sometimes the PM seems to "age" faster, sometimes slower.  When it gets very near replacement time, the number is pretty accurate.

battery life

by Tracey_E - 2021-03-01 09:24:45

It's not a gas tank that goes down and you can predict how many miles are left. I'm on #5. I've had it go down steadily. I've had it accelerate. I had a lead go bad and it tanked, needed a new one when the old was only 2 years old. I've had it stall and for almost 2 years they said I had 1 year left. Fortunately replacements are super easy. 

ditto

by dwelch - 2021-03-18 00:22:17

it is a gross estimate, ignore it until the units are in weeks.  really, ignore it, dont bother looking at it, it is bogus.

it is like a gas tank, no two taks will take the same time and get the same miles, too many variables.

Like Tracey_E I am on number five and I have had some go fast and some go slow and one the home stretch was three years, it kept looking like it was close but it wasnt...

Battery life is what it is, just like the amount of gas in the tank, when it gets to a certain point you just pull over and get some more gas.  Aint no thing.