Forgot anime name...? Any help please?

The main character is a weird mysterious doctor and most of the episodes begin with the phone ringing for his help, but he never picks up the phone, the people are made to record their messages (about their 'incurable' illness). I remember one of his patient had something wrong with his heart and he had to drink lots of water like they're 'painkillers'. Then I think he had to cut him up to look at his heart when its still beating.