A cyanotic newborn is suspected of having congenital heart disease. He has an increased left ventricular impulse and a holosystolic murmur along the left sternal border. The ECG shows left-axis deviation and left ventricular hypertrophy (LVH). Which of the following is the most likely diagnosis?

**Core Concept:**
Cyanotic neonates presenting with signs of congestive heart failure and heart murmurs are usually due to congenital heart defects that compromise the separation of the atrial and ventricular chambers. These cases present with characteristic ECG findings and physical examination findings.

**Why the Correct Answer is Right:**
The correct answer (D) is "Tetralogy of Fallot." Tetralogy of Fallot is a congenital heart defect characterized by four main abnormalities:
1. A large ventricular septal defect (VSD)
2. A right ventricular المخرج الانسداد (RVOTO)
3. Pulmonary artery stenosis
4. A right to left shunt through the patent ductus arteriosus (PDA)

In this case, the neonate has an increased left ventricular impulse, holosystolic murmur at the left sternal border, and left axis deviation on ECG, which are all consistent with RVOTO. Additionally, the ECG shows left ventricular hypertrophy (LVH), further supporting the diagnosis of tetralogy of Fallot.

**Why Each Wrong Option is Incorrect:**
A. Acyanotic neonates with RVOTO typically present with a systolic murmur at the right sternal border, not left.
B. Pulmonary stenosis would present with a mid-systolic murmur and not holosystolic murmur.
C. Patent ductus arteriosus would present with a diastolic murmur and not holosystolic murmur.

**Clinical Pearl:**
Tetralogy of Fallot is a common congenital heart defect that presents with characteristic clinical findings and ECG changes. Correct diagnosis is crucial for appropriate management and intervention.

**Correct Answer:** D

✓ Correct Answer: C. Tricuspid atresia