How to differentiate ASD from VSD in X-ray:

B i.e. Normal LA Characteristic findings of ASD include enlarged hea, RA, RV, PA and PV with normal LA & LV and decreased aoa and SVCQ Characteristic findings of VSD include enlarged hea, RA, RV, PA, PV and LAQ. So pulmonary overcirculation/congestion occurs both in ASD & VSD but LA remains normal in ASD & enlarges in VSDQ. Atrial Septal Defect (ASD) In atrial septal defect (ASD), there is a defect between both atrium leading to left to right (L-->R) shunt from left atrium to right atrium, to right ventricle (RV), pulmonary aery (PA) and then pulmonary circulation. Increased blood flow through pulmonary circulation causes hilar dance (increased pulsations of central pulmonary aery), pulmonary plethoraQ, increased size of pulmonary veins & anteries with size larger than accompanying bronchus (kissing cousin sign), dimeter of right descending pulmonary aery > trachea just above aoic knob, enlarged hilar vessels and visualization of vessels below 10th posterior rib (all indicating prominent pulmonary vasculature d/t over circulation). ASD may show cardiomegaly, normal sized left atrium & left ventricle and enlarged right atrium, right ventricle and main pulmonary aeryQ. Due to RV hyperophy, there is clockwise rotation of hea lit loss of visualization of superior venacava (S VC) and small appearing aoa with normal aoic knob. - Pulmonary pressure remains normal for decades and usually after 40 years of age onset of pulmonary hypeension causes increased R-sL shunting (Eisenmenger syndrome). Ventricular Septal Defect (VSD) - In VSD, there is a defect between both ventricles leading to L-sR shunt from left ventricle (LV) to right ventricle (RV) to pulmonary aery (PA) --> pulmonary vein -s left atrium (LA) -*LV. So all these chambers enlarge with pulmonary vessels being affected last - In nonrestrictive large shunts (>75% of aoic diameter) pulmonary aery hypeension Eisenmenger syndrome develops early. Calcification of PA is vathognomic of PAH.