The following features are true for tetralogy of Fallot, except
**Core Concept**
Tetralogy of Fallot is a congenital heart defect characterized by a combination of four key features: ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta. This complex congenital heart defect occurs due to abnormal development of the embryonic heart.
**Why the Correct Answer is Right**
The correct features of Tetralogy of Fallot include a ventricular septal defect, which allows blood to flow between the two ventricles; pulmonary stenosis, which obstructs blood flow from the right ventricle to the lungs; and right ventricular hypertrophy, which is a thickening of the muscle wall in the right ventricle due to increased workload. The overriding aorta, which receives blood from both ventricles, is another characteristic feature.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not mention the correct features of Tetralogy of Fallot. A common misconception is that Tetralogy of Fallot only includes a ventricular septal defect and pulmonary stenosis, but it is a more complex combination of four features.
* **Option B:** This option is incorrect as it may refer to other congenital heart defects, such as transposition of the great arteries or tricuspid atresia, which have different characteristics.
* **Option C:** This option is incorrect as it may refer to a different congenital heart defect, such as Ebstein's anomaly, which involves abnormalities of the tricuspid valve and right ventricle.
**Clinical Pearl / High-Yield Fact**
The "tetralogy of Fallot" acronym can be remembered as "VPSAO", which stands for ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta. This can help students recall the four key features of this congenital heart defect.
**Correct Answer:** A. This option is the correct answer as it is the only one that is incorrect, and the other options may refer to different congenital heart defects or features.