TABLE 86.3 AGE AND VITAL SIGNS OF INFANTS WITH CYANOSIS OR CHF/PULMONARY OVERCIRCULATION Age Weight gain Oxygen saturation RR HR BP Cyanosis CHF/Pulmonary overcirculation wks Normal 95% >50/min Slightly high Normal or arm HTN or leg lower than arm Normal, UE HTN, or LE < UE CHF, congestive heart failure; RR, respiratory rate; HR, heart rate; BP, blood pressure; HTN, hypertension; UE, upper extremity; LE, lower extremity Categorization of a patient into one of these four groups requires knowing the patient’s age, weight, vital signs, and physical examination findings, which all may be gathered quickly This simplified method of understanding heart disease can help the provider identify and treat emergencies due to CHD ( Table 86.3 and e-Table 86.1 ) Ductal Dependent Lesions After birth, circulating prostaglandins decrease and the DA naturally closes Cardiac defects, which depend on ductal patency for stable circulation, will present at this time, typically within the first weeks of life Either pulmonary or systemic blood flow may be dependent on a PDA These lesions will present with either cyanosis or shock, respectively Ductal Dependent Pulmonary Blood Flow Cardiac defects in which the pulmonary outflow tract is atretic depend completely on patency of the DA for survival When the ductus closes, these patients become extremely hypoxic and present with severe cyanosis and shock Defects such as critical pulmonary stenosis, pulmonary atresia with intact ventricular septum, and severe TOF present in this dramatic fashion