If you'd like a complete cardio workup, I'd suggest that you speak to your Cardiologist and ask him/or her for a carotid Ultra Sound, an echocardiogram, and a chemical stress test, if your Dr. feels this is in order.
I didn't realize that you had the problems that you do, Ides, and I'm sorry you're having these rough times!! Exercise does sound like it may be out of the picture at this point. Though, as Heidi mentioned, swimming might be something to ask about, if you thought you could manage it in the future. I, too, have some spinal damage from scarring from prior back surgeries along with arthritis, so I understand somewhat the limitations put on you-and swimming is what they advise for me.
Talk to your Dr.'s, make sure you are a complete part of your medical team-ask them questions and tell them your concerns. Much good luck and all the best to you!!