Beta Blockers

I have a dialated cardiomyopathy.  Diagnosed in 1990.  In past my EJ has been as low as 22%, over the past years it has improved to 50-55%.  I had an AV abilation 6 years ago, I am pacemaker dependent with a 100% paced rythmn.  Interigation of my pacer reveals my heart will not beat without the pacer.  Slowed to 10 beats per minute and nothing picked up.  My underlying rythmn is atrial fib with occasional atrial flutter.
I have a moderate leak in my MV and a mild leak in my other main heart valve.  In the past year my left atrium has decreased in size from 5.6 to 4.7/  EJ from 30-35% to 50-55%.  I have lost 90 pounds since August 98, and excersize regularly.

Three times beta blockers were given to me before the pacemaker placement.  I passed out all three times, with the last time requiring me to be coded.  My cardiologist feels there could be great benefit to me by now placing me on Coreg which could help the leaks in my valves and make my heart work even better.

Given my past history with beta blockers and the now fully paced rythmn, do you see any risks in trying the beta blocker?

I am 44, male, non-smoker, 165, 5'11". BP stays around 100/60 I have level III CHF. (or did, I don't think it is that bad now) and still have some edema. At one point was considering transplant, now looks like I will do fine on my own at least for a while.  I just want to get as much out of my present heart as possible.  How much excersising is to much?

I take Accupril, Coumadin, lasix, Potassium, spironolactone, Pamalor, and serezone.

[CCF CARDIO MD - DLB]

The exercising probably helped. As long as you do not have symptoms, you should be able to exercise to whatever level you would like. The beta blockers can slow the heart rate excessively - that should not be a problem in your case, since you already have a pacemaker that is essentially working 100% of the time.