Three types of natriuretic peptides (NP) have been isolated: atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). The NP family elicits a number of vascular, renal and endocrine effects that help to maintain blood pressure and extracellular fluid volume. These effects are mediated by the specific binding of NP to cell surface receptors that have been characterized, purified and cloned from cells of the vasculature, kidney, adrenal gland and brain. There are 3 subtypes of NP receptors: type A natriuretic peptide receptor (NPRA), type B natriuretic peptide receptor (NPRB), and type C natriuretic peptide receptor (NPRC). All 3 subtypes affect cellular second messenger activity. The literature currently does not define the levels of b-type natriuretic peptide (BNP) in children with congenital heart disease undergoing surgery.

The investigator wishes to perform a retrospective chart review to define BNP levels in the pediatric cardiac defect population and to evaluate the relationship of those levels with cardiac diagnosis, operation performed, post-operative course and outcome. The investigator will collect the following information from the medical record:

• Laboratory: BNP levels, serum pH, lactic acid, Co-ox, CBC, Chemistry
• Diagnosis
• Surgical Procedure
• Incidence of re-operation
• Length of ICU Stay
• Length of Hospital Stay
• Complications
• Length of Ventilation (how many days on the ventilator)
• Medications
• Cross Clamp Time
• Bypass Time
• Echocardiogram data
• Cardiac Catheterization Data
• Vital Signs
• Monitored Hemodynamic Measures
• Final outcome (discharged or death)