MRIs

Hello all!

I just thought I would share some encouraging news that I heard yesterday when my pacemaker was being interrogated. Maybe this is old news, but I didn't see anything posted about this.

Evidentally, while MRIs are not good for us pacers (alternating magnetic fields can destroy pacemakers), they do make shields ("isolation blankets") that reduce the effect of the MRI magnets on the pacemaker. So, I was told that if I, say, needed an MRI on my leg; it is entirely possible to have it done (under the supervision of the electrophysiologist).

I've looked at some research about this and I have found a good NY Times article: tp://www.scmr.org/news/mri_scans_pacemakers_nytimes.pdf.

The article mentions something about Medtronic's attempt at a MRI-friendly generator, but I guess they haven't marketed this yet.

Thought I would share this information!

Ethan

6 Comments

not to burst your bubble but...

by Tracey_E - 2009-04-21 04:04:39

My cardiologist told me the same thing when I broke my foot and it wasn't healing properly, and one of our local hospitals has mri equipment that is "pacemaker friendly". I asked my friend who's a radiologist about it and he was adamant that I not do it. He said radiologists are split, a few will do it but many, including his practice, feel it is not safe. The pacemaker will be fine, but the leads can more or less fry your heart and cause permanent damage.

And yes, they are working mri friendly pm's, but that won't help any of us that already have pm's. Even if we get the new, safe pm's, we will still have the unsafe leads. I'm hopeful that they develop other xrays that aren't based on magnetic fields. That research is more friendly for those of us with pm's.

Radiofrequency waves

by esperry - 2009-04-21 06:04:01

Yes, I suppose I forgot to mention one other aspect of MRIs that would be an issue for generators and leads. Radiofrequency waves are used by MRIs to conduct various dye-dependent studies. These waves (microwaves) are essentially thermal, which would heat up the device (and leads) as suggested by TraceyE.

However, I found marketed RF shields that should block these transmissions if applied carefully. Furthermore, any magnetic shield will help keep induction down in both the generator and leads, which should inhibit build-up of thermal energy.

The only issue, definitely a real one, is that there is no way to easily block deflected microwaves in your body from traveling up from the site of impact towards your heart. Magnetic field presence should be nearly completely reduced; but these electromagnetic waves can travel perpendicular to the intial direction of travel, which would heat up both the leads and pacemaker. I am no physicist, so I'm not completely sure if there are "enough" waves; or perhaps, enough photons to cause a significant build-up of heat against the metal in our hearts. I'll ask a physicist I know to see if he has any answers.

techie talk

by Tracey_E - 2009-04-21 07:04:17

I don't really understand all the how's and why's, I just remember the bugged out expression on my friend's face when I told him I was thinking about getting one my dr considered safe and his emphatic DON"T DO IT. He was an engineer before he went to med school, his original plan was biomedical engineering but he somehow landed in a radiology practice. If I were dealing with something more serious than a sore foot, I might revisit it but at this point, with my current leads, I would not consider it no matter how safe they told me it was.

Esperry...please talk English

by ted - 2009-04-22 02:04:45

Does anyone here understand Esperry's last comment? Could you explain it to us in simple language? I am no scientist, but I don't believe that any responsible medical professional would allow someone with a pacer to have an MRI. I is just foolhardy to play Russian Roulette with your life.

LOL

by Angelie - 2009-04-22 02:04:47

Finally......something that's funny. For one split second, it seemed as if my headache was gone.

You know......I've just been thinking.....
We can have all the fancy tech jargon in the world, but it still doesn't make us feel any better. I hate labels, and I don't know what the word is to describe my crazy heart....but it wouldn't make much difference anyways. It's still broken, and I have a headache.......

Angelie

sorry

by esperry - 2009-04-22 06:04:19

Well, all, I am sorry that I even attempt to better understand the machine that is currently keeping all of us upright. I had thought that perhaps someone on this website would be able to help clarify things for me, as I am attempting to understand exactly where the environmental and medical limitations are for me.

I have spent the entirety of my life dealing with medical issues. I have Cerebro Costo Mandibular syndrome, a genetic disorder likened to Pierre Robin syndrome. It has been a --requirement-- that I understand all that is happening to me; as I have had 6 ear surgeries, 3 heart catheterizations, and 16 reconstructive craniofacial procedures. I'm not looking for any sympathy or empathy; I don't need any. I am comfortable with who I am and what is wrong with me.

That said, there is a lot of bad science and bad medicine practiced in our world. I, myself, am a student-scientist who has four published papers, so I know first-hand how incorrect thinking and judgment can affect both minor and major issues. I have been a recipient of faulty orthodontic treatment that has elongated corrective efforts from a craniofacial perspective, both functionally (plastic surgery) and aesthetically (teeth alignment). I made it a personal goal ever since I was 9 to understand all I can about every procedure done; and this includes the nuts and bolts. While I would never attempt to "one-up" a doctor in the office, I do want to be as "in-their-shoes" as I can be, for as we all know, doctors can be very cryptic.

Up and to this point, only one other person I know has shared similar medical situations. While I talk to him daily, he is not, fortunately, under the care of cardiac physicians. Therefore, upon finding this pacemaker forum two weeks ago, right after I received my pacemaker, I thought I would try to see if I could better understand the device I now live with.

Clearly I have found the wrong forum for this, so I will return to reading medical journals myself and consulting with my parents, doctors, and professors about any questions I have. After all, there could be a point in my life where a detailed understanding of my pacemaker could save my life.

Oh, and Cabg Patch, I thought you would be interested in knowing that my MIT-trained physics professor agrees with my rudimentary analysis of the problem with both magnetic fields and radiofrequency waves. I don't like being so direct and condescending, but I just wanted to let you know that I am not quite the imbecile you and your "physicist friend" believe me to be.

I'm sorry for any hard feelings and for posting on this forum. I wish you all the best of luck with your current and future pacemakers and ICDs.

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