The following is false about Atrial septal defect –
**Core Concept**
Atrial septal defects (ASDs) are a type of congenital heart defect characterized by an abnormal opening in the atrial septum, allowing blood to flow between the left and right atria. This defect can lead to increased flow to the lungs and potential pulmonary hypertension.
**Why the Correct Answer is Right**
In ASDs, the shunting of blood from the left to the right atrium can lead to increased pressure and volume in the right-sided heart chambers. This can result in right atrial and ventricular enlargement, which is a hallmark of this condition. The increased flow to the lungs can also lead to pulmonary hypertension, a common complication of untreated ASDs.
**Why Each Wrong Option is Incorrect**
**Option A:** This statement is incorrect because ASDs typically present with a left-to-right shunt, not a right-to-left shunt. The shunting of blood from the left to the right atrium is a characteristic feature of ASDs.
**Option B:** This statement is incorrect because ASDs are often associated with right-sided heart enlargement, not left-sided heart enlargement. The increased pressure and volume in the right-sided heart chambers can lead to right atrial and ventricular enlargement.
**Option C:** This statement is incorrect because ASDs are often associated with increased flow to the lungs, not decreased flow. The shunting of blood from the left to the right atrium can lead to increased flow to the lungs, which can result in pulmonary hypertension.
**Clinical Pearl / High-Yield Fact**
A key clinical feature of ASDs is the presence of a fixed splitting of the second heart sound (S2). This is due to the increased flow to the pulmonary valve, which can result in a delayed closure of the pulmonary valve.
**Correct Answer: A. This statement is incorrect because ASDs typically present with a left-to-right shunt, not a right-to-left shunt.**