1) Transthoracic and transesophageal echocardiography are important modalities for assessing atrial septal defects (ASDs). TTE can identify RV volume overload and septal flattening, while TEE precisely measures defect size and evaluates rim morphology.
2) The four main types of ASDs - ostium secundum, ostium primum, sinus venosus, and coronary sinus defects - have distinguishing echo features. Doppler can demonstrate shunt direction and magnitude.
3) Echocardiography guides percutaneous ASD closure by assessing defect and rim anatomy, device sizing, and post-procedure result. Understanding echo features is key to ensuring procedure success.