Hey, I believe that's three of us who are 77! Pika is about that age, too!

There's a branch here ("Almost Over the Hill") for discussing problems special to us old-timers. You'll probably find stories similar to yours if you browse those posts.

As Glenn says, talk to your cardiologist, then start slow and work up gradually.

There are lots of good articles on lightening your pack on the home page of this site, left-hand column. This will reduce the strain on your heart and, if you've had bypass surgery, the old incisions. The 27-pound, 7-day gear list there is the one I used for my model 8 years ago. Actually, I'm now about 3 pounds lighter than that for a 7-day trip.