Limitations

leads

by Tracey_E - 2019-02-27 19:08:53

For every one person who comes here looking for answers because a lead is bad (or any other complication), there are thousands out there with no issues whatsoever, getting on with their lives. It makes problems seem much more prevalent than they are.

Leads last on average 15 years. Some don't make it that long, others last double that.  Occasionally someone does something to kill a lead but usually they just wear out or scar tissue builds up or something else beyond our control.

If your leads/box are very close to the surface and you lift heavy weights, you could possibly crush a lead. If you rowed competitively and practiced for hours and hours, you could possibly damage a lead. Other than those few extremes, it's unlikely we will damage a lead. They are thin and flexible and intended to move with us. 

It's not hard to tell when something doesn't feel right, when it's putting pressure on the box or leads. If that happens, back off. But really, you don't need to worry about it unless you're doing something extreme. I've done Crossfit for 8 years and don't hold back. I go heavy overhead, do pull ups and push ups, swing kettlebells. I ride roller coasters, and last summer I took a ride on an Olympic bobsled that pulled way more g's than any amusement park ride. I never pass up a chance to kayak, and my favorite new thing is those treetop ropes courses. I have one working lead from 1994, the other was replaced in 2010. Both are still going strong and my doctor encourages me to stay as active as I want. 

Leads

by Pink - 2019-02-28 01:50:01

Hi,

Leads can fracture or fray. It’s unfortunate but I’ve had two lead revisions. I’ve also on my 5th pacemaker, my first I got at 31 and I’m 46. 

My last lead revision I already had 3 leads in place and needed a complete revision. When they went to retract the oldest lead (13 years) it broke. I was in the Cath lab 8 hours and had many complications. 

Leads can fracture. I’m a young super active person. When you get a fracture you will know. People have different signs and symptoms. Shprtness of breath, possible arrhythmia, chest heaviness.

They day the first eight weeks limit your arm use. My leads fractured years after they were in place. 

Hope this helps.

Leads

by Wo bist du - 2019-03-01 01:47:50

It is variable leads can last from 5 years to 20 years plus. Depends where the positioning is not everyone is built the same. How much exercise you do. Repetative motions. Tension put on them. The type of leads that you have. How many leads you have. You will know if something happens. I just do not think about them. But I am disabled anyway, seizures etc.

Leads

by Wo bist du - 2019-03-01 01:47:50

It is variable leads can last from 5 years to 20 years plus. Depends where the positioning is not everyone is built the same. How much exercise you do. Repetative motions. Tension put on them. The type of leads that you have. How many leads you have. You will know if something happens. I just do not think about them. But I am disabled anyway, seizures etc.

The Leads are the......!

by donr - 2019-03-01 11:24:25

...weak link in the entirre system.  But they live the most dangerous life in the system, also.

A LOOOOng time ago, when I was a "young" EE at age 55, I wrote a letter as a gummint contractor about regular old IBM PC's & leads.  I said that when they expected the computer to be more reliable than the data leads connecting it to its world, they were being unreaLISTIC.   After all, the lead was just a chunk of wire - the electronic guts of a computer wer very compex & much more prone to failure.  Some 11 yrs later, I received my first PM - four yrs after that I had my first lead fail!  My cardio team & I discussed the situation closely & I had to eat my words - a new reality took over!

My conclusions changed.  When dealing w/ the PM system - leads, battery, box & electronics, the probabilities dramatically change because of the environments & sizes of everyhing.  Consider the following:

1) The box: Biggest & most robust part of the system .  hermetically sealed.  Only weak point is where the leads enter it.  Fabricated from Titanium.  Not subject to corrosion because of the materials.  Ti is the most corrosion-resistant of all metals.

1)  Electronic guts of the PM:  Very tiny. all integrted electronics, encapsulated & all on single circuit boards.  Leads between electronic components are microscopically short & firmly fixed to circuit boards.  Micro electronics are extremely robust & subject to many QA controls.  Also, they can build in back up circuits  & have back up programming that can work around some failures.  This stuff is the heaqrt of space probes controls & tougher than a braised combat boot smothered in gravy served in a cheap restaurant.

3:  Battery & capacitors (Capacitors found in ICD's).  Biggest items inside the box.  that's why the ICD is so big, compared to a PM.  Battery technology is imprving all the time.  Trying to come up w/ the ideal battery has been a real challenge - but the weak link in battery technology is life time & failure modes.  Depends a lot on how much power drain you have  for lifespan of the battery 0 but you get a warning when it is going to go belly uop on you.  And - it is reasonably predictble.  They don't just die instantly, nor do they leak - no liquids in them like the battery in your car.

4:  Ah, the LEADS!!~!!! The weakest link.  Also live in the harshest enviroment.  Considewr the small diameter of the lead & its construction.  It is not just a chunk of wire - it is a complex coaxial lead with two conductors - ome buried inthe center & the other surerounding it & braides for flexabuiiity.  There is an insulator between them & a protective sheath covering the outside.  Each end has to be perfectly sealed to the lead to preclude body fluids from entering the lead.  The human body has fluids that are corrosive beyond belief.  About the only materials that can survive foe any period of time are Titanium, plastics & some syainless steels.   And the stainless are sometimes kind of "iffy."  Genmerally, the leads have stainless outer conductors & silicone based sheaths  Dunno what the core conductr is.  The leads are also only about a half millimeter thick.  So think how small each cmponent of that lead is.  So, like John Lennon's song, imagine what goes on with that tiny lead - A human being, essentially BLIND, becqause he/she cannot directly view what they are doing during implant, remotely goes inside the heart & trys to sink a harpoon into the wall of th eheart.  the heart is beatibg & only stays still for fractions of a second at a time.  The surgeon has to view a shadow on a fluoroscopic display & time the placing just right into the wall.   Here's where most lead failures occur - poor placement of the anchoring of the lead.  Let's call it "Human failure."  When I was talking w/ my cardio about this, I ikened it to capt Ahab in "Moby Dick" sinking his harpoon into the flank of the great white sperm whale.  At which point, said great man lectured me on the difficulty of hitting the correct spot on a moing target in turbulent liquid, while partially blind.  Not only that, the view they have is a two dimensional representation of a three dimensional environment!.  So the EP gets the lead properly anchored.  Backs out & congratulates himself on another success.  Now the lead gewts flailed around by the blod changing direction every second, stopping & starting rather violently.  Every second, 24/7 That means that at 60 BPM, your lead gets whipped around over 3.6 million times a month - or about 40million times per year.  Which is about HALF A BILLION times in a ten yr life span.  Grab the charging cable for your cerlll phone.  It's coaxial, just like your PM lead.  Start bending it back & forth .  See if it lasts 3.6 milliion bends before breaking!  That's the kind of reliability we expect from a PM Lead.  Now think vewry small - like the diameter of that center conductor in a lead.  The finest imperfection in the materials of that lead becomes a major failure point.  That conductor must be as near perfect in every way (Mary Poppins!) for the lead to remain intct during its life span.  A bit of corrosion, a microscopicly small nick in its surface, a thin spot - all can lead to unexpected failure earely in life.

We read of failures in leads before the patient even leaves the hosp - probably a human filutre at planting it.  Ditto for those failure in the very early days.   What abiur my lead failure at 4 yrs?  probably due to fatigue failure & constant bending.  A microscoopic flaw in a lead?  Who knows? 

So what do we do about lifestyle?  Exactly what Tracey does - NOTHING!  You do what you want, when you want, how you want.  That's whaT i HAVE DONE, THOUGH NOT QUITE AS VIOLENTLY AS tRACY - AFTER ALL, i'M OLD EBOUGH TO BE HER FATHER.  (Sorry for the shouting - poor aim by the finger going foer the "A" key.)    Thesse failures are really quite rare - they aRE JUST CONCENTRTED HERE IN THE pmc.    (Poor aim again.)  So let not your heaert be troubled - just live life to its fullest & enjoy what you have.  Us engineers have your back - and remember that Lawyer's mistakes are jailed, Doctor's mistakes are buried.  We erect our mistakes for the world to see & marvel at and admire - like the Pisa Tower, the Tacoma Narrows Bridge  and the Edsal!

Donr

K POINT IS WERE THE JHEADS ATTACH.