▁such ▁a ▁comp lication ▁in ▁the ▁first ▁place . ▁Pul mon ary ▁hy pert ension ▁is ▁not ▁always ▁present ▁in ▁adult s ▁who ▁are ▁diagn osed ▁with ▁an ▁AS D ▁in ▁ad ul th ood ). ▁ ▁If ▁pul mon ary ▁hy pert ension ▁is ▁present , ▁the ▁evaluation ▁may ▁include ▁a ▁right ▁heart ▁c ath eter ization . ▁This ▁involves ▁placing ▁a ▁c ath eter ▁in ▁the ▁ven ous ▁system ▁of ▁the ▁heart ▁and ▁meas uring ▁press ures ▁and ▁o xygen ▁s atur ations ▁in ▁the ▁superior ▁v ena ▁c ava , ▁inferior ▁v ena ▁c ava , ▁right ▁at rium , ▁right ▁vent ric le , ▁and ▁pul mon ary ▁ar tery , ▁and ▁in ▁the ▁w edge ▁position . ▁ ▁Ind ividual s ▁with ▁a ▁pul mon ary ▁v asc ular ▁resistance ▁( P V R ) ▁ ▁less ▁than ▁ 7 ▁wood ▁units ▁show ▁regression ▁of ▁sympt oms ▁( including ▁NY HA ▁functional ▁class ). ▁ ▁However , ▁individuals ▁with ▁a ▁P V R ▁greater ▁than ▁ 1 5 ▁wood ▁units ▁have ▁increased ▁mort ality ▁associated ▁with ▁closure ▁of ▁the ▁AS D . ▁ ▁If ▁the ▁pul mon ary ▁ar ter ial ▁pressure ▁is ▁more ▁than ▁two - third s ▁of ▁the ▁system ic ▁syst ol ic ▁pressure , ▁ ▁a ▁net ▁left - to - right ▁sh unt ▁should ▁occur ▁at ▁least ▁ 1 . 5 : 1 ▁or ▁evidence ▁of ▁revers ibility ▁of ▁the ▁sh unt ▁when ▁given ▁pul mon ary ▁ar tery ▁vas od il ators