Which congenital heart defect is characterized by a left-to-right shunt?

Which congenital heart defect is characterized by a left-to-right shunt?

• A. Pulmonary stenosis
• B. Atrial septal defect (ASD)
• C. Ventricular septal defect (VSD)
• D. Coarctation of the aorta

Answer: (B)

Atrial septal defect (ASD) is characterized by a left-to-right shunt due to the presence of an abnormal opening between the atria, which allows blood to flow from the left atrium to the right atrium. In this condition, the pressure in the left atrium is typically higher than in the right atrium. As a result, oxygenated blood from the left atrium is shunted into the right atrium, leading to increased blood flow to the right side of the heart and the pulmonary circulation. This left-to-right shunt can result in volume overload of the right atrium, right ventricle, and pulmonary arteries, potentially leading to symptoms such as exercise intolerance, palpitations, and even atrial arrhythmias as the individual ages. Additionally, if not addressed, the increased blood flow can lead to the development of pulmonary hypertension over time. Understanding the nature and consequences of the left-to-right shunt in ASD is crucial for assessment and management of the condition in clinical practice. It is important to recognize how these blood flow patterns contribute to the overall physiology of congenital heart defects.

Atrial septal defect (ASD) is characterized by a left-to-right shunt due to the presence of an abnormal opening between the atria, which allows blood to flow from the left atrium to the right atrium. In this condition, the pressure in the left atrium is typically higher than in the right atrium. As a result, oxygenated blood from the left atrium is shunted into the right atrium, leading to increased blood flow to the right side of the heart and the pulmonary circulation.

This left-to-right shunt can result in volume overload of the right atrium, right ventricle, and pulmonary arteries, potentially leading to symptoms such as exercise intolerance, palpitations, and even atrial arrhythmias as the individual ages. Additionally, if not addressed, the increased blood flow can lead to the development of pulmonary hypertension over time.

Understanding the nature and consequences of the left-to-right shunt in ASD is crucial for assessment and management of the condition in clinical practice. It is important to recognize how these blood flow patterns contribute to the overall physiology of congenital heart defects.