American Board of Internal Medicine (ABIM) Certification Practice Exam

Which is a potential complication of atrial septal defect (ASD)?

1. Coronary artery disease

2. Atrial arrhythmias and stroke

3. Myocardial infarction

4. Valvular heart disease

The correct answer is: Atrial arrhythmias and stroke

Atrial septal defect (ASD) is a congenital heart defect characterized by a hole in the atrial septum, allowing blood to flow between the left and right atria. One of the most significant potential complications associated with ASD is the development of atrial arrhythmias and the increased risk of stroke. Atrial arrhythmias, such as atrial fibrillation, can occur in patients with ASD as a result of the right atrial enlargement and pressure overload, which are caused by the left-to-right shunt of blood. This altered hemodynamics can lead to electrical disturbances in the heart, predisposing the individual to abnormal heart rhythms. Additionally, patients with ASD face an elevated risk of stroke due to the potential for paradoxical embolism. This can happen when a thrombus (blood clot) from the venous system crosses into the systemic circulation via the ASD, especially during episodes of increased right atrial pressure. Once in the systemic circulation, the clot can travel to the brain, resulting in an ischemic stroke. Coronary artery disease, myocardial infarction, and valvular heart disease are not directly related to ASD complications. Instead, they can arise from different pathophysiological processes not inherently linked to