Can regular needles be used to get a shot to the heart?
You mean an intracardiac injection? No. It requires a longer needle than a normal injection would. It’s also an obsolete technique because there are better, faster, and safer, ways to get medications into someone, that don’t involve stabbing them in the heart and hoping you don’t cause a hemorrhage.
Anyway, as always, I’m not a doctor, and this is something that was certainly never covered in Scouts. So, I could be wrong here.