One may have only minutes to change the trajectory of a child who is deteriorating from either congenital or acquired cardiac disease. However, these children may present with rather cryptic patterns of symptoms (e.g. failure to thrive, lethargy, colic, neonatal shock, respiratory distress, wheezing and syncope with exercise). Thus, it is essential that any health care practitioner who cares for children be familiar with key clinical presentations that require consideration of underlying cardiac disease and time sensitive diagnoses that require rapid recognition and therapy in order to optimize the chances of saving the child's life. The objectives of this manuscript are: 1) to review the initial identification and management of cardiac emergencies in children; and 2) to present a brief summary of key cardiac diagnoses that may need to be considered when caring for children in an acute care setting.