# Aortic Stenosis and Bicuspid Aortic Valve

> Aortic stenosis and bicuspid aortic valve for NEET-PG Paediatrics covering outflow obstruction types, critical neonatal stenosis and exertional symptoms.

- Canonical URL: https://prepelephant.com/topics/neet-pg/paediatrics/aortic-stenosis-and-bicuspid-aortic-valve
- Exam / course: NEET-PG · Subject: Paediatrics
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-14
- Last updated: 2026-10-14
- Reference basis: Nadas' Pediatric Cardiology; Nelson Textbook of Pediatrics
- How to cite: "Aortic Stenosis and Bicuspid Aortic Valve", PrepElephant, https://prepelephant.com/topics/neet-pg/paediatrics/aortic-stenosis-and-bicuspid-aortic-valve

## Direct answer

Aortic stenosis is obstruction to left ventricular outflow, and in children a bicuspid aortic valve is a common cause of valvular narrowing. Critical neonatal stenosis presents with shock as the ductus closes, when systemic flow depends on the duct. Older children more often present with exertional syncope, chest pain or breathlessness.

## What you must remember

- **Obstruction types:** valvular (common in children), subvalvular (a discrete membrane or fibromuscular ridge) and supravalvular (as in Williams syndrome).
- **Bicuspid aortic valve:** one of the commonest congenital valve malformations, often with aortic coarctation and linked to Turner syndrome.
- **Critical neonatal stenosis:** severe obstruction in the first days of life, with systemic perfusion dependent on the ductus, causing shock and metabolic acidosis.
- **Prostaglandin use:** PGE1 may be used to keep the ductus open when it supplies the systemic circulation, a decision taken case by case.
- **Exertional symptoms:** exertional syncope, chest pain and breathlessness signal severe disease and carry a risk of sudden death.
- **Examination:** an ejection click, an ejection systolic murmur at the right upper sternal border radiating to the neck, and a slow-rising, low-volume pulse in severe disease.
- **Severity:** a peak velocity above 4 m/s defines severe stenosis; the valve is followed with serial echocardiography.

## Which obstruction, and what the child needs

The site of obstruction and the age at presentation decide the emergency and the elective plan. The steps below run from the neonate to the older child.

1. **Locate the site:** determine whether obstruction is valvular, subvalvular or supravalvular, since each has a different surgical route.
2. **Neonatal emergency:** a neonate in shock with weak pulses needs urgent echocardiography and, if the ductus supplies systemic flow, prostaglandin support.
3. **Balloon valvuloplasty:** a balloon is used in children with significant valvular stenosis to lower the gradient. It is often the first choice for suitable valvular anatomy, with surgery reserved for failure or unsuitable valves.
4. **Surgical choice:** the Ross procedure or a prosthetic valve replacement is chosen by age, anatomy and the surgeon's experience.
5. **Activity advice:** severe stenosis or exertional symptoms prompt restriction from competitive sport until specialist reassessment.
6. **Lifelong follow-up:** aortic regurgitation, ascending aortic dilatation and endocarditis risk are monitored through serial echocardiography.

## Where the exam tries to catch you

Outflow obstruction questions turn on the site and the pulse pattern. Watch for these traps.

- **Trap:** Calling a bicuspid aortic valve harmless because the child is asymptomatic. — **Correct:** It carries risk of stenosis, regurgitation, endocarditis and aortic dilatation, so surveillance is needed.
- **Trap:** Confusing aortic stenosis with coarctation of the aorta. — **Correct:** Stenosis obstructs the valve or outflow, while coarctation narrows the arch, so the pulse and blood pressure pattern differs.
- **Trap:** Describing the pulse in severe aortic stenosis as bounding. — **Correct:** Severe stenosis gives a slow-rising, low-volume pulse, whereas a bounding pulse suggests aortic regurgitation.

## Frequently asked questions

### What is the classic murmur of aortic stenosis in a child?

Aortic stenosis produces an ejection systolic murmur at the right upper sternal border that radiates towards the neck. An ejection click may be present with a bicuspid valve, and in severe disease the pulse becomes slow-rising.

### Why does critical neonatal aortic stenosis need prostaglandin?

In critical neonatal aortic stenosis the left ventricle cannot adequately perfuse the systemic circulation, so the ductus arteriosus may supply the body. Prostaglandin E1 keeps the duct open to maintain systemic flow until the valve can be opened or repaired.

### Why is exertional syncope important in aortic stenosis?

Exertional syncope in aortic stenosis reflects a fixed outflow obstruction that cannot rise with exercise, so cardiac output falls. It is a marker of severe disease and an indication for prompt specialist review and restriction from competitive sport.

### How is a bicuspid aortic valve identified on echocardiography?

Echocardiography shows two leaflets with a raphe, and the valve opens eccentrically during systole. Leaflet doming and aortic root dilatation help confirm the lesion and guide long-term follow-up.