Recovering from angioplasty and competitive swimming

I competed at the 2001 SCY nationals in Santa Clara and did my personal bests (since college anyway). A couple months later, I had my first bout with chest pain which was caused by a completely blocked coronary artery that was opened through angioplasty. After taking some time off, I got into it again and in late January, swam my personal unshaved bests since starting masters swimming. That same day, chest pain returned and I ended up having a second angioplasty done a couple weeks ago. The main cause is a horrible family history of heart disease, but I'm wondering if anyone else out there who swims competitively has had similar problems, and how you have gone about overcoming them. I'm only 41 years old and, in all honesty, this second "event" is harder psychologically than the first. Barring any further problems, I would still like to compete at nationals in Hawaii, and would welcome any advice you may have, especially from someone who has "been there". Thanks.