Hilar Dance Sign is seen in -

* can be normal in early stages when the ASD is small * Vigorous pulmonary aerial pulsations due to increased blood flow often seen in flouroscopically in pts seen with congenital Lt-Rt shunts especially Atrial Septal Defect. * signs of increased pulmonary flow (pulmonary plethora or shunt vascularity) o enlarged pulmonary vessels o upper zone vascular prominence o vessels visible to the periphery of the film o eventual signs of pulmonary aerial hypeension * chamber enlargement o right atrium o right ventricle o note: left atrium is normal in size unlike VSD or PDA o note: aoic arch is small to normal