Atrial Septal Defects

Abstract

Atrial septal defects (ASDs) are common and make up 7-10% of all congenital heart defects. They cause left to right intracardiac shunting and complications are related to the volume and duration of shunting. Approximately 50% of ASDs are treated via surgical or transcatheter means, while the remainders close spontaneously or are hemodynamically insignificant. Secundum ASDs are the most common, followed by primum and sinus venosus types. Echocardiogram as well as cross sectional imaging can be utilized in diagnosis of ASD type and associated cardiovascular anomalies, which occur in a third of patients. ASDs lead to asymptomatic right-sided heart dilation in the young child, however, if left unrepaired, may be associated with fatigue, dyspnea, and exercise intolerance in the adolescent or young adult. Longstanding hemodynamically significant ASDs are associated with atrial arrhythmias and, in rare cases, pulmonary hypertension and right heart failure. Untreated ASD is also a risk factor for paradoxical embolisms that could lead to stroke and transient ischemic attack. Closure is indicated for hemodynamically significant defects even in asymptomatic patient and recommendations are outlined by the American Heart Association.