Lower voltage

Hi all,

I went for my first pacemaker checkup since having it implanted, and the technician said the next time I came in ( in 3 months), they will lower the voltage of my PM from 3 volts down to 1.something, in order to increase battery life. Though I didn't say anything to her, I'm concerned: if I need 3 volts now, why would that change ? She said I'm 100% dependent on the pacer, so I'm not too quick to mess with what works. Any thoughts/ ideas/ experiences ? I have a Medtronic MRI Sure scan, if it matters.

Thanks !

6 Comments

Threshold

by golden_snitch - 2014-01-10 03:01:32

Sarroj,

the voltage always depends on your threshold. It is usually programmed 2x, 2.5x or 3x as high as your threshold, and thereby it is guaranteed that your heart will be stimulated effectively. So, no need to worry that 1. something V isn't enough. They have checked your threshold before and then calculated how much voltage you need to be on the really safe side.

I have 1.5V for my ventricular lead, the threshold is 0.75V, so it's progammed twice as high as the threshold.

Best

Inga

Inga explained it well

by BillMFl - 2014-01-10 09:01:04

All you need is enough voltage to get the desired results. Any more voltage will just shorten your battery life. And since its no picnic getting a replacement be glad you do well with a lower setting.

Me too

by SilverMegan - 2014-01-10 12:01:39

I have a Medtronic Sure Scan as well and had my first post procedure checkup yesterday. My tech said the same thing about lowering the voltage in three months. I also got a copy of my report.

You won't notice

by Theknotguy - 2014-01-10 12:01:54

I just had my 3 months plus 1 day today. Had my PM check and got the voltage lowered. Don't notice a thing. I have the Medtronics Sure scan too. It's a great piece of equipment.

They use higher voltage to "train" the heart when you first get the PM. Then, as the heart settles down, the voltage goes down because your heart will react with the lower voltage. It gives you better battery life too. (Don't really want to rush having them cut me open again.)

I wouldn't go with the tech saying you're 100% dependent. It appears on my scans that I'm 100% dependent but I'm only 23 / 24 % dependent. During rehab the PM fires for every beat from 100 up to 120 but what the PM is really doing is to make sure I get a consistent heartbeat. Get your cardiologist's ruling on the amount you are pacing.

My heart can no longer beat now, miss the next beat by a fraction of a second, decide to miss the next beat, then give three fast beats in a row. Now it has to march to the metronome of the PM and give me a consistent and full beat. So even though it appears I need the PM, I really don't. My heart would keep beating but not with the same consistency. (I was getting tired of being dizzy and gasping for breath.)

Also with the Sure Scan, it will take strong magnetic fields with no problems. You can have an MRI with no problems. If you do get into a strong magnetic field your Medtronics will drop down to a "maintenance" mode of max 85 beats per minute. So you get less of a jolt if you get into a magnetic field.

Oh, and you won't even notice when they drop your voltage. I was visiting with my tech (she looks like my daughter-in-law so we really hit it off) when she dropped the voltage. Didn't know she dropped it, didn't feel a thing. In fact she had more problems getting the report printed off on the printer than scanning and setting my PM.

Remember to ask for your PM report. It's good to have when people ask questions. I asked the tech and she ran it off. No problems.

Sit back, enjoy your new piece of technology. Keep looking forward to getting better. Enjoy life. You've got a lot of living to do.

Theknotguy

Thanks for the comments

by sarroj - 2014-01-11 08:01:19

I'm sure I'll still be nervous, but I'll temper that with what I've read here. :)

asfafasf

by boxxed - 2014-01-17 06:01:02

Capture is binary. You either make the heart beat when you pace or you don't. If your capture threshold is 1V, anything less than 1V won't make heart beat. Anything above 1V will make it beat. Throwing more energy down doesn't make it beat "better". Lowering output won't make it beat "worse".

So really she's just saving you energy. It's very, very common practice.

Also, alot of newer PMs have adaptive capture or autocapture or some variation. It runs test to find that threshold and periodically adjusts the programmed output on it's own to make sure that your output is always 1.5x or 2x your threshold.

You know you're wired when...

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