Traditionally the measurements of cardiac indices and hemodynamic variables require invasive monitors such as pulmonary thermodilution catheters and transesophageal Doppler echocardiography. In recent years, electrical cardiometry has been used for the non-invasive determination of stroke volume, cardiac output, and other hemodynamic parameters in adults, children, and neonates. Electrical cardiometry has been validated against "gold standard" methods such as thermodilution and is a proprietary method trademarked by Cardiotronic, Inc. (La Jolla, CA). Cardiotronic markets the ICON™. It is FDA-approved for use in pediatric and adult patients, is currently used for clinical purposes in the BCH MSICU at 11 South.