Tread carefully here when it comes to advice. Caffeine is a well known trigger for arrhythmia. It has great potential to be harmful to people who deal with that problem. How does caffeine relate to other heart issues such as cardiomyopathy? I don't know--and that is my point. We, outside the medical profession, aren't up to speed on the specifics of your topic. That is why we need to be guided by your doctor. Your cardiologist can advise you. And by all means follow his advice. This really is a case where you life can depend on it.
I too have been warned about the "dangers" of coffee from co-workers, friends, and sometimes health care workers, but I also have not found any evidence that supports the idea that caffeine, when used responsibly, is dangerous. In fact, caffeine has some properties similar to the drug Pletal, in that it will increase the flexibility of red blood cells, allowing them to move more easily through circulation.
My uncle, who is a doctor, is a huge fan of coffee. So I don't see any problem in standing by my old friend- caffeine.
The caffeine thing seems to relate to who you are talking to. There seems to be much disagreement as to its effects. After bypass surgery, I quit caffeine, but the docs said not to worry about it. So I don't.
In fact, my cardiologist keeps a coffee pot going in his waiting room so his patients can have a cup while they wait.