'thumps' to set your clock by after i c d and biventricular pacer

[strobdoc]

i am a 67 yr old retired physician.
i have had several stents placed on 2 separate
occasions and a ventricular aneurysmectomy [in
2001].

i had a guidant icd and biventricular pacer
placed in march 2006 for ischemic
cardiomyopathy.

the first evening after placement i had
intermittent spasms in my back causing visible
'jerks'.
a technician came to the room and adjusted the
output which relieved them completely.......i
thought.

when i got home i began having them again
quite often throughout the day and my local
cardiologist adjusted the output of the device in
jan 2007
this abolished all of the "jerks" or "thumps", [as
i called them], with one exception.

the thumps are in the left upper quadrant of the abdomen and
feel like what  i imagine  a pregnant lady feels when a
baby kicks.
they are not unbearable, but more of a nuisance.
they are visible and palpable by  another
observer.

this is where the story gets strange .

almost every day since the adjustment i noticed
that i was having them in the afternoon...just a
series of 2 or 3 thumps.
i started keeping track of the times they
occurred.
the time was always between 1:28 - 1:32 p m.

when daylight saving came they occurred
between 2:28 - 2:32 pm., exactly one hour later!
i don't have them at any other time.
i could set my watch to them and be correct
within 4 minutes.

i discussed this with my cardiologist and he had
no idea what caused them.

i wrote to boston medical, who took over
guidant, and have received no response after 2
weeks.

can anyone give me a reason this might be
occurring?

i should add that about a month after placement
i developed a bruise just above the pacer
followed by an  erythema, [reddness] and tenderness over
the implant that finally cleared after 6 weeks of
antibiotics.
there were no systemic symptoms.
my cardiologist told me it couldn't have been a
pocket infection.

also i need to mention that the device improved
my ef from 20 up to 35%, and my symptoms are
vastly improved.

[Momto3]

My dad gets the "thumps" too.  He had an Bi-V ICD implanted in November 2006 and one of the leads runs along the nerve.  The doctor explained that when that happens, sometimes the patient can feel a "hiccup" in the abdomen.  My dad has dealt with the odd sensation for several months, but has decided to ask the doctor to make additional adjustments.  The doctor explained that he may have to turn off the third lead (it is the Bi-V lead) and just allow the regular pacemaker and ICD to work.  He was hoping that by inserting the third lead, he might also experience an improved EF.  He is going tomorrow to see the EP, so we'll see where things are at that time.

Do you know if your lead runs along the nerve?

[strobdoc]

i should correct my first statement.
my cardiologist knew what caused them, and so did i, but we can't figure out the clockwork feature.
i tried the forum and will keep trying but they evidently get their quota quickly.

doc

[fwilson3]

This would be a guess, but as a former software designer with some biotech knowledge, I would guess the pacer/ICD is performing some type of calibration function once a day.

Send out a pacing signal and see what the return signal is, and adjust the output of the device accordingly.  Corrects for gross tissue changes and generator issues.

Just a guess.

[strobdoc]

thank you fwilson3.
i was thinking along those same lines....that almost has to be the case.

i feel like the crocodile that swallowed the alarm clock.

doc

[strobdoc]

i am not sure if it runs along the nerve or not.....i believe it is just stimulating the diaphragm.....but the big question is why just at that time of day????

thanks for responding.

[anacyde]

I would wonder if it was pacing you at those times, but since it's like clockwork, that would be quite odd.  I've heard of this, though not frequently.  If you're not getting any response from boston, I would try posting this question in the forum that the Cleveland Clinic doctors answer here on MedHelp.  I believe one of the doctors is a rythm specialist, if I read correctly in prior posts.  Probably a good person to answer your questions.  Give it a try.

I'm very happy to hear your EF has gone up nicely over the past year and that your symptoms have improved so much  That's definitely some great news!  I wish you continued improvement.  Hopefully you can get some answers soon about the thumps.

[mariop]

I had essentially the same sentation, except for the timing.  At one point it got so bad I felt like my chest was in a microwave oven.  Naturally my EP said it was in my mind and not my chest.  I had them turn off the pacing function of my ICD and the problem went away.

I went to a neurologist because I thought it might be a nerve problem.  She told me that my abdominal wall was being paced and if I restart the pacer I should have the leads re-installed or the voltage adjusted.

If you go to pacemakerclub you will find a lot of complaints like these.

[fwilson3]

LOL, Nice analogy.

If you can get through to a developer they might be able to change the timing to when you are asleep if they are soft enough not to wake you.

By the way, you might not want to anounce you are a doc.  On this board doctors know EVERYTHING, and we patients nothing.  This little exchange might cause the board to implode.

[Momto3]

fwilson3,

Excellent point!!  I remember the EP telling my dad that the recordings and some of the machine functions occur during sleep time (for my dad's BI-V ICD)....Ironically, a lot of the weird sensations occur during the evening or when he is lying down at night.

By George, you may have figured out the puzzle!!

strobdoc,

I would be very anxious to hear anything you come up with regarding the regular timing of the "thumping."  It makes a lot of sense that it would be an internal signal of some sort.  

I'm hoping my dad's EF has also increased as a result of using the new unit.  Good luck to you!

[mariop]

I wear an ICD and it is programmmed to do a self test once a day and if anything is off it will beep for ten seconds.  This is not a test of the patient but a test of the device itself.  The tech person that sets it up can set it to anytime you want.  My ICD is by Medtronic and this info is explained in their manual.

Nevertheless, other devices may be different than mine.  But I would check the manual that comes with the device.

[strobdoc]

thank you for all the posts.
i am not going to bother with changing the settings.
after several months of this, it isn't a concern so much as curiosity as to the cause.
i will inform my cardiologist.

btw, i have been retired for over 2 years so i have forgotten 95% of everything i knew and the other 5% has changed.

thanks again.