Congenital heart disease which causes death in the first week of life –
**Core Concept**
Tetralogy of Fallot (TOF) is a congenital heart defect characterized by four main features: ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta. TOF is one of the most common cyanotic congenital heart defects, which can lead to severe cyanosis and potentially life-threatening complications, especially if not treated promptly.
**Why the Correct Answer is Right**
In TOF, the combination of right ventricular hypertrophy and pulmonary stenosis results in a significant obstruction to blood flow from the right ventricle to the lungs, leading to a decrease in pulmonary blood flow. This, in turn, causes a right-to-left shunt through the ventricular septal defect, leading to systemic cyanosis. The severity of cyanosis and the risk of complications are highest in the first week of life, making TOF a significant cause of mortality during this period.
**Why Each Wrong Option is Incorrect**
* **Option A:** **Truncus Arteriosus** - While truncus arteriosus is a cyanotic congenital heart defect, it typically presents with signs of congestive heart failure and respiratory distress rather than sudden death in the first week of life.
* **Option B:** **Atrial Septal Defect** - Atrial septal defects are generally well-tolerated and may not cause significant symptoms or mortality in the first week of life.
* **Option C:** **Coarctation of the Aorta** - Coarctation of the aorta is a congenital heart defect that can cause hypertension and heart failure, but it typically does not present with sudden death in the first week of life.
**Clinical Pearl / High-Yield Fact**
Tetralogy of Fallot is often associated with a characteristic "boot-shaped" heart on chest X-ray due to right ventricular hypertrophy.
**Correct Answer:** C.