▁deviation ▁of ▁the ▁Q RS ▁complex , ▁while ▁those ▁with ▁a ▁sec und um ▁AS D ▁have ▁a ▁right ▁axis ▁deviation ▁of ▁the ▁Q RS ▁complex . ▁ ▁Ind ividual s ▁with ▁a ▁sin us ▁ven os us ▁AS D ▁exhib it ▁a ▁left ▁axis ▁deviation ▁of ▁the ▁P ▁wave ▁( not ▁the ▁Q RS ▁complex ). ▁ ▁A ▁common ▁finding ▁in ▁the ▁E CG ▁is ▁the ▁presence ▁of ▁incomplete ▁right ▁bundle ▁branch ▁block , ▁which ▁is ▁so ▁characteristic ▁that ▁if ▁it ▁is ▁absent , ▁the ▁diagn osis ▁of ▁AS D ▁should ▁be ▁re cons ider ed . ▁ ▁Tre at ment ▁ ▁Pat ent ▁For amen ▁O v ale ▁ ▁Most ▁patients ▁with ▁a ▁P FO ▁are ▁asympt om atic ▁and ▁do ▁not ▁require ▁any ▁specific ▁treatment . ▁However , ▁those ▁who ▁develop ▁a ▁stroke ▁require ▁further ▁work up ▁to ▁identify ▁the ▁et i ology . ▁In ▁those ▁where ▁a ▁compreh ensive ▁evaluation ▁is ▁performed ▁and ▁an ▁obvious ▁et i ology ▁is ▁not ▁identified , ▁they ▁are ▁defined ▁as ▁having ▁a ▁crypt ogen ic ▁stroke . ▁The ▁mechanism ▁for ▁stroke ▁is ▁such ▁individuals ▁is ▁likely ▁em bol ic ▁due ▁to ▁par ado x ical ▁em bol i , ▁a ▁left ▁at rial ▁append age ▁cl ot , ▁a ▁cl ot ▁on ▁the ▁inter - at rial ▁sept um , ▁or ▁within ▁the ▁P FO ▁tunnel . ▁ ▁P FO ▁Cl os ure ▁ ▁Until ▁recently , ▁patients ▁with ▁P FO ▁and ▁crypt ogen ic ▁stroke ▁were ▁treated ▁with ▁anti plate let ▁ther