Stress Test/RVG Results

I am a 61 year old white male who had a massive heart attack and triple by-pass at age 41.  The past 20 years have fortunately been uneventful and I have had no symptoms or problems.  I just switched to a new cardiologist who is very promient and in whom I have a great deal of faith.  On a recent echo stress test, I went for 13 minutes achieving 15 METS.  The echo seemed to indicate that my ejection fraction was in the mid forties; however, my new cardiologist did not think that was reliable and recommended and RVG nuclear medicine test.  The RVG results were rather alarming, indicating an ejection fraction fo between 25 and 30. (Previous RVGs from many years ago were about 36.)   My cardiologist has recommended that I consider a pacemaker.    I have been on Altace for many years and on Coreg for a few years.  My cardiologist has also recommended that I double the Coreg dosage. Do you have any recommendations?  Are there any other treatments that could help?  Are there any promising experimental treatments that would be suitable?   Most disconcerting to me is that I have been very optimistic through the years because I have always done exceptionally well on my stress tests and have no limitations or other problems.  However, these recent results seem to indicate that my heart is worsening and I am now very concerned.