I like this article that describes the signs and symptoms of dehydration: "Validity and reliability of clinical signs in the diagnosis of dehydration in children" by M Gorelick et al.  Pediatrics 1997;99(5).  

While we encounter more children in the ED with 'known' than 'suspected' congenital heart disease, reviewing the evaluation of children with 'suspected' congenital heart disease reminds us of our typical cardiac evaluation of children.