Perioperative Echocardiographic Assessment of Atrial Septal Defect: Key Learning Points for Fellows/Residents in Training

chambers.Unlike other left-to-right lesions like ventricular septal defect, patent ductus arteriosus, there is isolated volume overload of the pulmonary circuit in ASD.Therefore, the onset of pulmonary arterial hypertension (PAH) usually has a delayed, gradual onset in the natural history of ASD.Significant PAH usually starts developing after 25 years of age and the incidence rises to nearly 35% in patients after 40 years of age. 5 ASD with significant PAH at a younger age should initiate the search for other concomitant lesions known to cause PAH and evaluation for primary pulmonary hypertension.Chronic right ventricular volume overload with/without pressure overload leads to tricuspid annular dilatation, tricuspid regurgitation (TR), flattening of interventricular septum, and RV dysfunction.Right atrial dilation can predispose to atrial arrhythmias. PathophysiologyThe pathophysiologic consequence of ASD depends upon the degree of left-to-right shunting, which, in turn, depends mainly upon the size of ASD and the relative compliance of the right and left ventricles (LVs).There is diastolic volume overload of RA and right ventricle (RV), which leads to enlargement of the right-sided