▁tr anst hor ac ic ▁e ch oc ardi ography , ▁an ▁at rial ▁sept al ▁defect ▁may ▁be ▁seen ▁on ▁color ▁flow ▁imag ing ▁as ▁a ▁jet ▁of ▁blood ▁from ▁the ▁left ▁at rium ▁to ▁the ▁right ▁at rium . ▁ ▁If ▁ag itated ▁sal ine ▁is ▁inject ed ▁into ▁a ▁peri pher al ▁ve in ▁during ▁e ch oc ardi ography , ▁small ▁air ▁b ub bles ▁can ▁be ▁seen ▁on ▁e ch oc ardi ographic ▁imag ing . ▁ ▁B ub bles ▁travel ing ▁across ▁an ▁AS D ▁may ▁be ▁seen ▁either ▁at ▁rest ▁or ▁during ▁a ▁c ough . ▁( B ub bles ▁ ▁only ▁flow ▁from ▁right ▁at rium ▁to ▁left ▁at rium ▁if ▁the ▁right ▁at rial ▁pressure ▁is ▁greater ▁than ▁left ▁at rial ). ▁Because ▁better ▁visual ization ▁of ▁the ▁at ria ▁is ▁achieved ▁with ▁trans es oph age al ▁e ch oc ardi ography , ▁this ▁test ▁may ▁be ▁performed ▁in ▁individuals ▁with ▁a ▁sus pected ▁AS D ▁which ▁is ▁not ▁visual ized ▁on ▁tr anst hor ac ic ▁imag ing . ▁Ne wer ▁techniques ▁to ▁visual ize ▁these ▁defect s ▁involve ▁int rac ard iac ▁imag ing ▁with ▁special ▁c ath eters ▁typically ▁placed ▁in ▁the ▁ven ous ▁system ▁and ▁advanced ▁to ▁the ▁level ▁of ▁the ▁heart . ▁ ▁This ▁type ▁of ▁imag ing ▁is ▁becoming ▁more ▁common ▁and ▁involves ▁only ▁m ild ▁sed ation ▁for ▁the ▁patient ▁typically . ▁ ▁If ▁the ▁individual ▁has ▁ade qu ate ▁e ch oc ardi ographic ▁windows