Welcome @cbowman1, My daughter had an S-ICD implant but had to switch to a pacemaker due to some issues with the S-ICD randomly shocking her when there was no reason for it to be set off. Here's some information I found on your question while you wait for members who may have some experience to respond.

"It is also strongly advised not to tattoo over the top or too close to your device. This is because the device or wires could be damaged or affected by the tattoo process and the skin over the device could be compromised more than a tattoo usually would."
--- Tattoo or NOTattoo: https://www.suddencardiacarrestuk.org/2021/10/tattoo-or-notattoo/

Have you discussed getting a tattoo to commemorate surviving heart failure with your care team?