Can lead fracture cause sudden death?

Sudden loss of ventricular pacing - very unpleasant...

by crustyg - 2024-09-25 03:17:04

Fracture of a ventricular pacing lead can cause sudden loss of RV pacing (and naturally LV pacing in most cases).

The commonest cause of sudden loss of ventricular pacing is a large anterior infarct (MI) causing complete heart block.  Many patients in this condition who make it to hospital have a residual junctional rhythm of around 30BPM, which for most people will produce enough BP when lying down to sustain life, but it's not pleasant.  Fixed (temporarily) with IV drugs to raise the HR (not always effective) and a temporary pacing wire followed by permanent PM+leads implantation.

Sounds to me as though your EP-doc is giving you an accurate, unvarnished answer to your question.  But a sudden drop of HR leading to sudden drop in BP leading to faintness could easily have fatal consequences, depending on what the patient is doing at the time.  Sudden loss of pacing itself may not be fatal, but fainting at the wheel at 70mph or at the top of a flight of stairs could be.

I would try to stay calm

by Gemita - 2024-09-25 04:00:13

Did your EP warn you that your father is at high risk if he doesn't replace the faulty lead immediately?   Has your EP actually confirmed what has happened to your lead and advised an immediate replacement?  If so, follow his advice.  If not, I would try to stay calm.

I hope you can get a second opinion quickly, so that your father’s pacemaker will not suddenly fail him.  However, may I make one respectful suggestion please that you do not perhaps overthink any of this and cause your father undue anxiety by talking to him about sudden cardiac death due to his lead.  There are always risks whatever decision/path in life we take.  Getting a second opinion is a sound one.  If your father needed emergency care due to a failing lead, I am sure he would be advised to receive a replacement lead immediately but I am not hearing this, or seeing your father needing to attend the ER for emergency treatment on a regular basis although I know you have sought emergency advice and reassurance on several occasions.

I believe from your past messages you mentioned your father was largely symptom free and that he still has time (one+ year?) before his device battery will need replacing.  I am not sure how much battery power the noisy, faulty lead is using up?  As long as you have adequate battery power to fuel the faulty lead and your father is monitored closely by his current EP and your father reports any worsening symptoms should they occur, he should remain safe.

Symptoms from a faulty lead could include any of the following, depending on your father’s heart condition and need for pacing support at any given time.  Symptoms of lead fracture may vary, depending on your father's pacemaker-dependency and on the degree of loss of capture and may include a slower than programmed heart rate, a faster or pausing, irregular one.  This could lead to dizziness or syncope, the symptoms that perhaps your father had before he received his pacemaker?  Blood pressure could also be adversely affected.  Your father may feel uncomfortable pulses, stimulation/twitching in perhaps different areas of his body, like the diaphragm.  He may notice hiccups.  Since your father has two leads, the faulty lead may cause dyssynchronised pacing between the two heart chambers where the leads are placed, so he may develop worsening palpitations.  He may become confused due to a lack of oxygen from inadequate blood flow.

It will perhaps always be unhelpful to compare your father’s situation with another patient who will obviously have a different health condition, a different need for pacing and whose lead may have a different degree of fracture, malfunction.  Personally, I would spend more time focusing on finding an experienced, sympathetic EP capable of helping your father to safely have a new lead placed as soon as possible, rather than focusing on sudden cardiac death.

Lead failure

by piglet22 - 2024-09-25 05:54:44

Hello 

I haven't looked at all your past information, but you have mentioned spikes of noise.

Pacemaker leads have a hard job to do. They have to preserve very small signals in a very challenging environment and are designed as well as possible to take this into account.

I can only speak on similar measurements in industry and the closest measurement would be pH or redox. Both are millivolt level and high impedance. Long runs of cable and flexing the cable can lead to noise completely swamping the signal.

Great care has to be taken in every aspect of design and use and it's hard to think of anything as difficult and essential as pacemaker leads.

A pacemaker lead is about 50-cm which is approaching the limit of reliable, noise-free use for pH for example. To achieve the best performance, often an amplifier is built into the electrode which does away with all the lead restrictions. At die level, an amplifier chip could be the size of a pin head.

It's quite likely that this will have been looked at for pacemakers..

If I were diagnosing a pH lead problem, I would connect up an oscilloscope and flex the lead and connector until I could see noise on the display. An ECG would be the equivalent of the scope.

Not an easy job to do with an implanted lead.

One of the causes of electrical lead or cable failure is the tendency of copper to work harden and it becomes less ductile or flexible the more it is used.

Junctions at connectors or electrodes are common causes of noise due to movement fracture.

As I understand it, the pacemaker leads are not simple straight lengths of wire, but are coiled which increases the flexibility and if a fracture or partial fracture happens, there might be a better chance of maintaining function.

Intermittent faults are the hardest to find and often need further recording equipment to detect.

I would have thought that if this is the case with your father, the first port of call for lead expertise would be Medtronic working in conjunction with your existing team.

Clearly, any suspicion of a failed or failing lead needs prompt attention.

You've mentioned getting a second opinion or going elsewhere, but I wonder if this is the right course of action. What would reassure me more than anything would be a joint exercise involving the lead experts, Medtronic, and your pacing team.

I'm sure it will be resolved. With 7 years of use, generator replacement will be looming, another factor to consider.

current EP visit yesterday

by smopace - 2024-09-25 16:46:07

The EP said if my father is not EP dependent, he would not bother for lead revision procedure. Since the short v-v interval is introduced by arm movement and there is no tendency of increasing, so he is ok to wait till changing battery time. It is "elective" procedure for now. He thinks the short v-v interval is  introduced by between  two leads in the insulation area ( I don't quite understand this). I asked him how he verify his fix during the procedure. He said he will rotate the two leads to make sure there is no "noise".  There is no drop in battery longevity. 

I asked if it is possible to increase the frequency of interrogation for pacemaker to monitor the change, right now it is 90 days to every 30days. He refused to do so. 

I asked my current EP how many lead revision he does every year, he said it is 100/year ( one day  every week) that includes implant of pacemaker since not many people need to do lead revison. In his career, total 1000 cases. He only practiced two years and two year fellowship for EP. This does not seem to add up together.  That probably included his other fellowship practice. 

I have one expericed EP for second opinion in about one month.  When you seek a second opinion vs become a patient, do you think the doctor will have different treatment plan? Which one is more neutral?

Thank you for your input

Leads

by piglet22 - 2024-09-25 19:14:03

A bipolar lead has two conductors side by side separated by insulation.

The two conductors behave as a capacitor and this can affect the signal.

This is why flexing a high impedance lead can introduce spurious voltages and the importance of reducing impedance early in the signal path.

Another issue is crosstalk.

It's mainly a problem in digital systems.

Wired computer interconnections use pairs of separate conductors in a cable called a CAT5, 5e, 6, or 7.

There are strict rules on the radius of bends, but importantly, each pair of individual wires are twisted together which reduces the crosstalk or spurious signals transferring from one to another.

A typical CAT5e cable or Ethernet or LAN cable will have 8 wires, 4 pairs twisted together.

The name of the game in all these cases is to preserve the integrity of the signal.

Changing the capacitance by movement in a lead can introduce subtle timing errors.

You can be certain that this exercised engineers brains in the early days of pacemaker development.

Is this Metronic technican question?

by smopace - 2024-09-25 19:53:03

I don't know if EP understands the principle of the pacemaker about how it works inside it.

Surgeon’s skill and training vs #s performed

by Rch - 2024-09-26 00:26:22

Hi

Generally a younger surgeon trained at a reputable institution with newer AI/ robotic technology is perhaps as good or even better skilled than an older surgeon who has performed hundreds of procedures but with mostly older technology. Some older surgeons learn the newer technology on the job or in a 1-2 week mini-fellowships offered by the manufacturer at medical conferences. I personally would rather have a young Asst. Professor operate on me than the department chairman! But that's just my opinion. So, please keep an open mind and pick the surgeon who you feel comfortable working with! I wish you well.

Thanks for sharing your thought

by smopace - 2024-09-26 01:47:56

I am wondering if pacemaker lead revision procedure utilize any robotic technology? I believe very complex heart surgery would use advanced technology.