The Next Idea If ever there is a time you want your physicians to be on top of their game, it's when he or she is determining your diagnosis. Yet, doctors who are overworked and stressed do make mistakes. And the results can be fatal. One famous case: actor John Ritter was diagnosed and treated for a heart attack. Turns out he actually had a tear in his aorta, which killed him. Dr. Vineet Chopra is with the Patient Safety Enhancement Program, and he's researching ways to change the way