John - I know it must be frustrating to be able to get an erection but not climax. I am not a physician but there are a couple of questions that I think are important and their answers may help you figure out what's going on. 1.) How long has this difficulty been going on? Did it follow the surgery or the addition of some of these medications. If so, talk to your cardiologist about these issues; 2.) Can you reach a climax through masturbation but not intercourse? If so this may be a matter of insufficient stimulation and working with a sex therapist may be helpful; and 3.)Have you considered the possibility that you suffer from retrograde ejaculation? Read about it and ask your doctor if this could be the problem.