Generally speaking, by nature, opiates are not all that hard on the body. Of course with excess, water can be dangerous to drink too much of. I’m also not sure if opioids (synthetic opiates) are as safe as naturally occurring opiates. Where opioids are certainly harmful to your system is when they are scaled with Tylenol or any other OTC anti-inflammatory NSAID. I’ve always been amazed that they would put Tylenol into a pill that would be abused by some. However, from my understanding, when an opiate/opioid had another med in it, and therefore not really meant for the spoon, they used to be a Schedule III, whereas a straight opiate/opioid medication has traditionally been a Schedule II. They’ve now changed that to where most opioids are Schedule II, except for Tylenol III’s and IV’s (with Codeine) is a Schedule IV or V. Also, if you are one of the unfortunate types where the constipation issue with opioids hits you particularly hard, you could cause great stress on the heart by trying to push so hard that it stresses the heart particularly hard. (Reference Elvis)
I’d bet your heart pain is from something else unless you’ve gone through a part of your life where you’ve done a lot of abusing of these drugs.