Very sorry to hear about your health issues. As for my thoughts, my first is: Would you really disregard the advice of the healthcare professionals who are familiar with your medical condition based on what some strangers on the internet say? C'mon man.
My second is, stop weightlifting and talk to your cardiologist. Don't just lift on the down-low. Tell him/her how much you enjoy heavy weightlifting, and how anxious you are to resume it. Ask him/her to review the recent medical literature on heavy weightlifting as it relates to someone with your condition, and to make recommendations based on that review. Once your cardiologist gives you his/her opinion re the risk/benefit profile of heavy weightlifting, you can then decide if it's worth it.