tweeking settings for more battery life

Has anyone ever got the impression that E.P.'s and pace maker technicians ( company reps) are reluctant to tweek to extend battery life because it actually results in less revenue; Or perhaps even replacing a p.m. before going into the EOL mode?

6 Comments

Interesting !

by IAN MC - 2015-04-16 01:04:11

I have always been intrigued by the fact that, in the US , you have manufacturer's reps directly involved in patient care.

Do they act in the patient's best interests or in the best interests of their employer ? I think there is only one answer to that question particularly if their salaries / bonuses are related to PM sales.

Here in the UK , tweaking of PMs is only ever done by highly-qualified technicians who are part of the cardiology team and have no links to individual manufacturers.

When it comes to health , i don't think vested commercial interests should have any place at the patient interface.

Ian

Pacemaker techs

by golden_snitch - 2015-04-16 01:04:46

In Germany, pacemakers/ICDs/CRTs are always checked by cardios. Nurses usually prepare everything, and sometimes dowload the data, but the whole interrogation and change of settings, if necessary, is only done by cardios. The head of the technical service of my manufacturer will be coming in soon to change a setting - it's in the "expert settings" which only techs can access -, but not even he's allowed to do so without the presence of my cardio.

The main setting responsible for battery life is pacing threshold and voltage (also called "amplitude"). That's the energy required to stimulate the heart effectively. The threshold is the minimum energy required to stimulate the heart, the pacing voltage is programmed higher to be on the safe side. Many pacemakers nowadays automatically monitor the pacing threshold and adjust the pacing voltage accordinly, mine does that every 24 hours. If a technician wants to shorten battery life, he'd have to switch this setting off and program a pacing voltage that's maybe a bit too high. To be honest, I doubt that anyone would do this intentionally.

I'm glad that my cardio is keeping an eye on everything. However, sometimes I'd wish that there would be a pacemaker tech from the manufacturer at every interrogation, because - at least sometimes - they really know their devices better. But on the other hand, I'd never feel comfortable, if only a pacemaker tech from the manufacturer would to the interrogation. My cardio knows my whole history, the techs only look at "their" device.

a bit too cynical

by Tracey_E - 2015-04-16 07:04:11

They are going to do the replacement regardless. What difference does it make to them if it's now or in 3 or 6 months?? We're not talking years of difference.

I've always had mine replaced before EOL by choice. I don't want to go into EOL mode!!!! I pace every beat so I want to have it done when it's fully functional.

From what I can gather, a big thing they can do to make the battery last longer is reduce the safety margins. If you are not super consistent in your usage, they will not want to do this. It's for your safety, not for their benefit.

Need to make a profit

by doublehorn48 - 2015-04-16 08:04:44

Several months ago I started having shortness of breath while running. So I went to my cardiologist and after some adjustments by the tech the problem, I thought , was solved. I then went in to talk to the cardiologist and was told my leads were starting to fray and would have to be replaced in the near future. These are my second set of leads. These have lasted, at this point, around eight years. The ones before, that are still in my heart lasted fourteen years. When I asked the cardiologist why the difference in the life of the leads, he said it was like a car. If your car lasts longer, the car company won't make as much money. To put more leads in some leads will have to be extracted with laser surgery. I'm now looking at hospitals where they have done a lot of these procedures since there is quite a bit of risk.

No zawodniak2

by Grateful Heart - 2015-04-16 10:04:19


I don't get that impression. Our settings are programmed for whatever we need individually. They have an abundance of patients so I don't think that is an issue.

In fact, my EP made a voltage adjustment on mine about 4 years ago due to an issue I had and he said that should extend my battery life. I have a CRT-D that is more than 6 years old. I am paced 100% in the ventricles, 95% in the atria so my device keeps pretty busy. My last interrogation showed I had 4 more years of battery life left. I'm hoping it's right....or close to it.

Grateful Heart

Your Cardio is speaking....

by donr - 2015-04-17 01:04:50

.....without thinking and is dead wrong.

NOTE: Edited at 0740, EDT, Fri, 17 April.

Doublehorn, no one can see the leads except on X-Ray & They just do not have the resolution to show items measured in the hundredths of a mm - necessary to detect fraying.

A lifetime ago for some of us, I was a rather old marketing manager for a major factory automation company. Specifically, they sold controllers that drove CNC machines and ran processes. We were selling a control system to the Govt against a specification for a lead reliability. The interesting thing about the reliability spec was that it was lower than that of the computer it connected to the process being controlled. In our proposal I commented that they had their specs backwards - no way could the computer (with all its complexity) be more reliable than a lead. The Govt contracting officer responded "OK" and we received the contract.

FFWD from 1988 to today. Boy was I ever wrong about that lead & that computer! At least as far as PM's & their leads are concerned.

In the PM/Defibrillator cases, the LEADS are the weakest link. I have discovered that to be true, but I went & looked up the data for a Medtronic lead - because I knew the model number for one.

Cumulative probability that a lead will make it to the 12 yr point in the ventricle is better than 95%. The same figure for the Atria is nearly 99%. The quality of leads has been continually improving, rather than growing poorer.

Leads must survive in one of the harshest environments known - the human heart.

1) Corrosive fluid surrounding it
2) From the moment it is implanted, it faces turbulent blood flow around it in the Ventricle that changes direction about 3.5 Million times per month - all the time its tip must stay embedded in the wall.
3) Fatigue failure is expected to be common & the data shows that is correct. Lead dislodgement is WAAAAAY down on the list.
4) How he could say/a straight face that your leads are getting frayed is beyond me. The exterior of the leads is a flexible polymer that most likely would not fray. Just inside the polymer is a stainless steel braided sheath that acts as the return conductor. This may start to fray as individual wires fracture from the back & forth bending. You would have to have a very good X-Ray to ever see such minute effects of fracture. I had one fail completely at only 4 yrs - most likely from brittle fracture induced by the continual flexing.
5) Failure to capture is a common cause of lead failure. That could be caused by the continual flexing of the lead causing the lead's components to change resistance.

I would be looking for a new EP.

Donr

You know you're wired when...

You have a dymo-powered bike.

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I consider my device to be so reliable, that I never think about a failure.