Pacemaker battery scandalBMJ 2016; 352 doi: https://doi.org/10.1136/bmj.i228 (Published 04 February 2016) Cite this as: BMJ 2016;352:i228
All rapid responses
When undertaking training from a company making leadless devices, I calculated the current drain from this device to be 5uA. Obviously this is a VVI device but when the drain from the same company's traditional devices is often around 13-15uA for a DDD system it does beg the question why these efficiencies cannot be transferred to the traditional design. As for inductive charging I have often wondered about this. Myself I have a spinal cord stimulator which charges via induction. It needs to be charged every day (two at the most) and can be fiddly to do. I can see that for elderly patients this could be an issue and these do make up the vast majority of the pacemaker population.
However, as battery technology has improved and efficiency has evidently improved, the other question to be begged is whether we could have combination systems - a small non-rechargeable five year battery and a rechargeable one. This would mean any charging issues would be detected at yearly follow ups without decline in function. Firmware issues could be solved with updates at clinic - the technology for this already exists and to monetise the manufacturers could charge for new algorithms. Game changing software such as MVP et al would obviously generate income and might encourage manufacturers to be more creative.
Do remember though that rechargeable batteries do not last forever - my device is rechargeable but still has a lifespan of only ten or so years.
As for programming - we have all seen poor programming which has often been left for years, wasting battery and increasing the risk of heart failure with pointless RV pacing. As the NHS is looking to save money we should be looking at our programming as often with a simple technique (for example using VDD in CHB rather than DDD when there is normal sinus node function) you can add two years to the battery. Testing pulse duration for high thresholds is an obvious one, but how many people look at impedances in both unipolar and bipolar and select the optimal impedance for longevity in patients in whom a box change might not be in their best interests? All this takes time and I feel that time pressures with this "do more with less" attitude leads to a decline in quality and ultimately higher costs for the NHS and for patients.
Competing interests: No competing interests
John Dean and Neil Sulke are to be congratulated on their editorial highlighting the relevant issue of battery life in patients with implanted devices. Although the issue is relevant to all patients, the issue is particularly acute for patients with defibrillators and cardiac resychronisation therapy devices where some devices deplete after a few years.
There is no doubt that smart programming, delaying device change, and reassessing patients for device therapy is important, and not done as rigorously as it should be. It is perhaps time to develop guidelines. There is no doubt that there are vested interests which are protected by shorter acting devices.
The variability in battery life between manufacturers is now well recognised after a series of articles, many cited in the text of the editorial. The differences are there to see in the manufacturers product performance reports, but the dense nature of the texts means that most cardiologists do not view them.
It is time the NHS procurement system moved to assessing the cost of the device per year, rather than looking at the up-front costs of the device, which currently seems to be the most pressing concern of accountants. It is time that patients were truly informed about the differences between devices; I agree with Dean and Sulke that many would opt for a device with a longer battery life to avoid surgery and its inherent discomfort and potential for complications.
Competing interests: I have received educational support / lecture fees / advisory board fees from Medtronic, Boston, St Jude, Biotronik and Sorin (Now LivaNova).
As an engineer working with miniature safety monitoring devices that utilise battery technology, I am astounded by this state of affairs.
In the space of only five years our industry has moved from radio safety edge monitoring and control devices that weighed more than a kilo and a battery the size of several torch cells and lasting only a few months, to tiny devices using lithium cells little larger than a watch battery (CR2032) with a minimum life of two years. The crux of this lies not with battery technology but the ever increasing use of electronic components that are smaller, more complex and with very little current draw, especially in the quiescent stage when monitoring only is being undertaken.
This has also brought about huge savings in cost: hard wiring no longer being needed for most applications and all monitoring with low energy radio technology. This is true of both safety edge monitoring as well as photo-beam technology, and the units have an end of battery life signal generated six weeks prior to failure.
In other areas we now have inductive charging that requires no electrodes being exposed and charging taking place through the actual insulation of the product (think rechargeable toothbrushes and shavers). Why not then the skin?
It seems to me that vested interests are holding back the technology to maximise on the profits that can be made by not advancing technology too rapidly (I couldn't believe the prices being charged). Batteries have not advanced very much over the past ten years but the associated products they power have become miniaturised and take less and less power for the same outcome than ever before.
It's time the medical device industry was subjected to the scrutiny of electronics specialists from other industry sectors.
Competing interests: No competing interests