Atrial Septal Defect

Overview

An atrial septal defect is an abnormal opening between the atria. The most common form in adults is the secundum ASD.

A left-to-right shunt usually results in right atrial and right ventricular volume loading.

Clinical Features

Many patients remain asymptomatic for years. Larger defects can cause exercise intolerance, atrial arrhythmias, or pulmonary vascular disease.

Fixed splitting of S2 and a systolic flow murmur are classic findings.

Investigation

Echocardiography demonstrates the defect, shunt, chamber enlargement, and associated abnormalities.

Complications & Management

Significant untreated defects may lead to arrhythmia, pulmonary hypertension, or paradoxical embolization.

Closure is considered according to defect anatomy and haemodynamic significance.

Clinical Pearls