I am in my late 30's and was diagnosed with nonischemic congestive cardiomyopathy based on a ecocardiogram about a year and a half ago. Dr. said ejection fraction is between 40 and 50 and I was proscribed an ACE inhibitor. At my most recent visit I was set up with a Holter monitor and the Dr. said I had one ventricular tachycardia event, over the 24 hour monitoring period, which lasted for a few minutes. I have had no noticeable symptoms related to the cardiomyopathy nor tachycardia. I consider myself pretty physically fit and complete in and train for several endurance athletic events each year (marathons, 50k, 50 mile, triathlon, century rides) all done with no noticeable symptoms. The Dr. has been pushing for me to start a Beta Blocker in addition to the ACE inhibitor, but I am concerned that this may impact my ability to continue to compete in endurance athletics at my current level. I also don't really want to be on any medication for an extended period of time if it is not necessary. Questions are, do I need to be on the ACE inhibitor and/or Beta blocker. What types of side affects should I expect if I were to start the Beta Blocker, both general and those related to competing in endurance athletic events.