The overall hea size in tetralogy of Fallot is usually:
**Core Concept**
Tetralogy of Fallot (TOF) is a congenital heart defect characterized by four classic anomalies: ventricular septal defect (VSD), pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta. The overall heart size in TOF is affected by the degree of pulmonary stenosis and the presence of right ventricular hypertrophy.
**Why the Correct Answer is Right**
The overall heart size in TOF is typically decreased due to the right ventricular hypertrophy, which results from the increased resistance against which the right ventricle must pump blood. The hypertrophied right ventricle becomes smaller and more compact, leading to a decrease in the overall heart size. This is in contrast to conditions like hypertrophic cardiomyopathy, where the heart size is typically increased.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the overall heart size in TOF is not typically increased due to the right ventricular hypertrophy.
**Option B:** This option is incorrect because while the right ventricle is hypertrophied, the overall heart size is decreased, not increased.
**Option C:** This option is incorrect because the heart size in TOF is not typically normal due to the presence of right ventricular hypertrophy.
**Clinical Pearl / High-Yield Fact**
The "tet" in TOF refers to the four classic anomalies of the condition: T (truncus arteriosus is a different condition), E (ventricular septal defect), T (tetralogy of Fallot), and R (right ventricular hypertrophy). This mnemonic can help remember the classic four anomalies of TOF.
**Correct Answer:** C. Decreased