I'm not a health professional, but as long as you can work out as you are doing, I'd continue. I'd add a caveat that I recently lost a best friend with a similar heart diagnosis while on the stationary bike, please don't work it too hard.
EF levels vary from test to test. The gold standard, I believe, is an echocardiogram, but a angioplasty will give lots of information. I've had a long hx of heart issues, this is simply my suggestion: have an angiography and echo as you can within your means, get as much information as you can. Always ask for a procedure report afterwards.
Regarding your question: I have a defib device. Some of the drugs that control goofy heart beats, in my experience Amiodarone, can have some very nasty side effects... nasty meaning in my case serious vision issues. Given what you have posted, I'd go with a device before drugs.
Thank you so much for responding to my question! I have an appointment with a Doctor to discuss implanting a new device called the S-ICS which goes in under the skin below the arm pit, and then a wire is run along the breast bone and up the rib cage. I heard that the new device is supposed to have less misfires and that no wires go into the heart which sound like this is the option I will have to choose. Thanks again for writing and for your advice. God bless...