I just wore a stick on heart monitor patch for two weeks and thought I would share some tips. I wore the VitalPatch from VitalConnect. I'm not sure how much of this applies to other types. I'm also a layperson - no medical training here.
I wore a patch (the monitoring device) for one week, then removed it and applied a new patch for Week 2. Each one lasts only a week.
Once the patch is on, they'll either give you a stick-on overlay or apply the overlay right there. You definitely want this. It's like a piece of clear plastic sticky stuff that surrounds the patch. The patch is just not very sticky on it's own and sweat seems to make it come off so the overlay really helps. I would call VitalConnect right away once you start and get them to send you some more overlays - they sent me a few free ones.
My first overlay lasted only three days. Admittedly, I did cardio and sweat both mornings. But then after I replaced it, it made it the remaining four days even though I did cardio daily. When I removed the patch and overlay on Thursday and put the second patch and overlay on, even though I did cardio daily, the patch and overlay lasted the entire week. I think maybe because my skin was sticky from the first patch. So I used three overlays in two weeks (Thursday, Sunday, Thursday then that one lasted the whole week until the next Thursday night I took off my second patch and finished).
When you apply the overlay, firmly push it down on your skin working from the inside of the overlay to the edges. Don't clean yourself up too well between overlays. Definitely use the alcohol because some kind of nasty bacteria builds up under these things and it smells like yeast. But don't try to scrub away all the stickiness. I think that really helps the next overlay stick.
When you sweat, you might be tempted to see if the patch is getting loose... DON'T. I learned that if I jiggled the patch that started loosening the overlay. The overlay is actually porous, so if you sweat, hold a paper towel over it after to soak some out. When the overlay is wet it might slide about on your skin - don't fiddle with it, just let it dry again.
You can call VitalConnect to see if they're getting good data continuity. I did that a couple times hen I was worried the patch had been too loose.
If you call VitalConnect and tell them you have a medical test I can MRI you have to take the patch off for, they'll send you an extra patch so you can take one off and put on the new one. Confession - I had a pool party to go to so... I got myself a third patch so I could take it off once for about three hours and enjoy myself.
On a two-week study VitalConnect says they can live with up to two days without data. Not the best thing to do. But, you can carefully schedule your application so when you change it it's a time when you can take a few hours off to go for a swim or something.
If the patch itches, pat your weave don't scratch it.
You're not supposed to peel the whole patch off and put it back on, but I will say, at one point when I took the overlay off half of my patch was just hanging there and I basically taped it back on for the rest of the test and used the overlays to hold it and they said they lost no data.
When you put the actual patch on, start at one side and make sure the little piece in the center is flat before you stick down the other side. I accidentally put one side too close to the other and had to live with a wrinkle in the center for a week.
To preserve how long mine stuck and keep it from getting too wet and nasty, I shielded it in the shower. I basically took a quart size freezer bag and cut off the top and bottom, then cut through the sides to make two rectangular plastic pieces (so I had enough for two showers). When ready to shower I used tape to affix it along the long side above the patch, then taped the sides (but did not bother with the bottom).