Lead requires too much voltage

Voltage

by agelbert - 2011-01-17 07:01:07

From the book Cardiac Pacing for the Clinician I obtained some information which may help you.

Threshold capture voltage above 2.5V reduces battery longevity.

Lead placement is critical to keep the voltage requirements low because the voltage requirement to depolarize the myocites (heart muscle cells in the node which depolarize and send the wave of muscle contraction) increases exponentially with the distance from the node. Consequently, a high voltage requirement can be a symptom of lead deposition.
Also, a breach in lead insulation or a broken lead can cause a high voltage requirement.
As you see, there are many possible factors. I just listed three.

Normally, after an operation, the threshold voltage requirement increases for a period due to inflamation inside the heart as a response to lead placement. As the inflamation goes down and fibrous tissue surrounds the lead, the voltage requirement goes down and reaches a plateau. BUT, it never gets as low as it was at the time of implantation.
So you can see why the cardio techs have to adjust threshold capture during the first three months.
I'm not a doctor but I believe your voltage is kind of high. It's not just a matter of using up the battery too quickly either. You really don't want frequent relatively large voltage pulses as a routine situation.
By the way, I also read that the ideal time interval for pulsing is from 0.4 to 0.6 ms. Less or more pulse duration decreases battery life. Your interrogation report shows the pulse time interval.
Good luck

depends why

by Tracey_E - 2011-01-17 08:01:21

When they turn it up, it's because the signal is not getting through either because it's impeded or it's not in a good spot. I had an old lead that was impeded and they had to keep turning it up as it got worse. I eventually had it replaced, but I waited until the battery died.

Picture cranking up the air conditioner to cool the house when the window is open. The house still cools but your power bill goes up, i.e. the battery runs down faster than it should. If it's new, they might be able to reposition it to get a better connection or replace it if it's impeded. I would definitely ask, turning it up makes the battery run down faster which is annoying but not critical but there's a window of how long they can reposition vs replace, usually about a year. After that year, replacing is more of a hassle because they can't just pull out the old one. You will definitely want to address it well before that year anniversary is up, waiting longer just makes it more complicated.

Possible lead extraction due to increased voltage

by Lisarose - 2020-08-24 01:29:28

Hi NDBill,

I just had a double lead extraction for this very reason, my atrial lead was requiring 5+ volts to fire, I was due for battery change so had both leads and pacemaker switched out, procedure occurred under general anesthetic with over night in cardiac ICU, my leads had been in for 9 years, so there was a lot of scar tissue to cut through, but this occurred with a specialized laser lead extraction tool, all went well except for the formation of a large hematoma that will eventually heal.  The only other issue is that it seems the new ventricular lead is sitting close to my phrenial nerve, so when I ventricular pace, it causes a pretty intense twitching, coughing sensation.  So now, I have been re-referred back to the surgeon for consult to move the lead away from this nerve.  Hope this information is what you were seeking, and the lead being too close to nerve could have happened at any time, it’s not a result of the leads being replaced.  Take care, Lisa