Question
A neonate has central cyanosis and short systolic murmur on the 2nd day of birth.The diagnosis is ‑
| A. |
Tetralogy of Fallot’s |
| B. |
Transposition of great vessels |
| C. |
Atrial septal defect |
| D. |
Ventricular Septal defect |
Show Answer
|
Correct Answer » B Explanation |
 |
- Transposition of the Great Arteries (TGA) is the most common cause of cyanosis presenting within the first few days of life.
- In TGA:
- The aorta arises from the right ventricle.
- The pulmonary artery arises from the left ventricle.
- Systemic and pulmonary circulations run in parallel rather than in series.
- Survival depends on mixing of blood through:
- Patent foramen ovale (PFO)
- Atrial Septal Defect (ASD)
- Ventricular Septal Defect (VSD)
- Patent Ductus Arteriosus (PDA)
- The murmur is often absent or only a short systolic murmur because there is no significant obstruction in uncomplicated TGA.
- The uploaded notes describe TGA as presenting with:
- Cyanosis from birth or shortly after birth
- Single second heart sound (S2)
- Murmur often absent
- Egg-on-side appearance on chest X-ray
Why the Other Options Are Incorrect
A. Tetralogy of Fallot (TOF)
- Cyanosis usually develops after several weeks to months, as pulmonary stenosis worsens.
- Neonates with classic TOF are not typically cyanotic on the 2nd day of life, unless pulmonary obstruction is severe.
- TOF usually presents with:
- Ejection systolic murmur
- Single S2
- Hypercyanotic (Tet) spells occurring later in infancy.
C. Atrial Septal Defect (ASD)
- ASD is an acyanotic congenital heart disease.
- Neonates are usually asymptomatic.
- Cyanosis is not an early feature.
D. Ventricular Septal Defect (VSD)
- VSD is also an acyanotic congenital heart disease.
- Symptoms generally begin 6–8 weeks after birth when pulmonary vascular resistance falls.
- Cyanosis develops only after long-standing pulmonary hypertension leading to Eisenmenger syndrome.