Although neurohumoral stimulation is similar in children to that in adults with HF, there are significant physiological variations between children and adults, notably regarding alterations in development that are most noticeable in newborns. A significant number of cardiovascular medications that have a solid database for lowering the hazards of unfavorable cardiac outcomes are selective beta 1 adrenoceptor inhibitors. The gene discussed is ADRB1; the disease is hydrops fetalis.