 The aim of the study is to evaluate the ability of a new FDA-approved non-invasive Electrical Velocimetry EV cardiac monitor called AESCULON Cardiotronic Inc, La Jolla CA to detect and trend hemodynamic changes in hospitalized ambulatory pediatric patients during recovery from acute illness. We postulate that if the cardiac monitor can trend hemodynamic changes in hypertensive patients whose mean arterial pressure MAP decreases to normal levels, or hypotensive patients whose MAP increases to normal levels over several days, it may improve our understanding of different disease processes and allow us to improve care. We also seek to establish normative data for different measures provided by the AESCULON monitor - specifically cardiac output CO and systemic vascular resistance SVR, which are the prime determinants of MAP. 