Pacemakers + Beta Blockers and Competition Training

This is my first posting to this site. I’m hoping to get some input regarding my training situation. There’s a bit of a story involved, but I’ll be brief. I started swimming five years ago at the age of 45 after a heart attack. I re-learned to swim on a masters team with the help of my very patient coach. To say that swimming changed my life would be to understate in the extreme. Last Fall (at first reluctantly) I began competing in meets here in Los Angeles. I got hooked, and made great progress, my times dropping as we moved through the meet season. As much as my cardiologist is amazed by my training, his evaluation of certain elements of my condition led to my having minor surgery this past May to implant a defibrillator/pacemaker. There was no incident or event that prompted this decision, and I’ve never had any problem while training. I was out of the pool for 6 weeks and have since built back up to a training schedule of 5 days a week 3-4K yards a session. My strength and endurance are coming back to pre-procedure levels, if more slowly than I’d like. Getting my speed back is a little more frustrating. After the procedure, I was prescribed a low dose of a beta blocker—Coreg. Even at this low dose I’ve seen a drop in my resting heart rate as well a significant change in how my heart rate accelerates with exercise. Where once I had to swim quite slowly to keep it at 120bpm for a fat burning set, I now have to work a set pretty hard to get it up past 120. In going through a work out, the rate does step up in stages and can reach 135-140, but only after 30 or more minutes. Stoke work ups it more quickly. During rest the heart rate drops quickly back to resting rate. I’m hoping that there will be those of you who have experience with training on beta blockers and/or coming back from a pacemaker or defibrillator procedure, especially in relation to how it may have affected competition. I’m also interested in finding a cardiologist in the Los Angeles area who treats athletes and/or participants in sports at a competitive level. Thanks for your time… Luke Reichle