Obstructive Valvular and Non-Valvular Lesions

Prevalence of 4 in 10,000 live births and is more common in males

Often associated with VSD and bicuspid aortic valve

1. Limited antegrade blood flow during foetal development, resulting in maldevelopment of the aortic arch
2. Ductal tissue migration into the thoracic aortic wall during development

Genetics, e.g. Turner syndrome, DiGeorge

Acquired presentation is rare but can be related to Takayasu arteritis

1. Juxtaductal – insertion of ductus arteriosus (most common)
2. Other (preductal, abdominal, infrarenal) – proximal to the left subclavian artery or within the abdominal aorta (less common)
3. Tubular Hypoplasia – enlarged narrowed segment (rare)

Potential features within a clinical history include:

1. Early onset hypertension or hypertension resistant to antihypertensives
2. Lower limb claudication

Difference in the upper and lower limb blood pressure

Ejection systolic murmur – heard loudest in the left upper sternal border or back

Male

CXR – features depend on the severity and age. It can be normal, have posterior rib notching (collateral vessel enlargement) or cardiomegaly (pulmonary venous congestion)

Echocardiogram – definitive and will show a discrete thoracic aortic narrowing with a pressure gradient.

1. Mild-to-Moderate
   1. Asymptomatic or hypertension
   2. Enlarged collateral vessels permit blood flow around the narrowing
2. Severe
   1. Critical presentation within the neonate
   2. Closure of the ductus arteriosus causes cardiogenic shock

Severe coarctation in the neonate requires prostaglandin E1 to maintain ductus arteriosus patency and then emergency surgical repair.

Non-critical coarctation repair is dependent on the age of the patient. If less than one year, then surgical repair is often used. If older than one year, then surgical or percutaneous repair is utilised.

If there is recurrent coarctation, then stent or balloon angioplasty is utilised.

Complications include treatment resistant hypertension resulting in coronary artery disease, cerebral aneurysm, aortic dissection, aortic pseudoaneurysm or coarctation recurrence.

Prognosis is often excellent in those with isolated CoA but often will require life-long antihypertensive treatment and cardiology follow-up. In the context of other abnormalities, there is a higher risk of long-term complications.

Occurs in more females

The key consequence of PS is increased right ventricular strain and pressure. In mild-to-moderate cases, patients are often acyanotic and without cardiac signs. However, in severe cases, right ventricular failure can result.

1. Valvular
2. Supravalvular ( e.g. intracavitary or infundibular)
3. Subvalvular
4. Peripheral (or branch)

Mild-to-moderate cases are often asymptomatic. However, severe PS may report syncope on exertion, chest pain, exertional dyspnoea and fatigue.

1. Ejection systolic murmur loudest at the left upper sternal edge
2. Right ventricular heave (left sternal edge)
3. Signs of right-sided heart failure, e.g. peripheral oedema, hepatomegaly, raised JVP.
4. Cyanosis (if ADS or PFO is present)

Dysmorphic features, e.g. Noonan, Williams

Chest X-ray – normal (mild or moderate), cardiomegaly/right ventricular or atrial enlargement (severe)

Echocardiogram with Doppler – visualisation of valvular pathology and systolic pressure gradient

1. Mild PS – rarely progresses, therefore observation and monitoring
2. Moderate PS – percutaneous balloon pulmonary valvuloplasty or surgical valvuloplasty
3. Severe PS

1. No cyanosis or respiratory distress
   1. Percutaneous balloon pulmonary valvuloplasty or surgical valvuloplasty
2. Cyanosis or respiratory distress
   1. Oxygen supplementation and prostaglandin E1 to maintain ductus arteriosus patency and percutaneous balloon pulmonary valvuloplasty
   2. Surgical valvuloplasty

Potential complications include pulmonary valve insufficiency after valvuloplasty, right-sided heart failure, and risk associated with valvuloplasty procedure.

The prognosis is related to PS severity. In mild PS, even if untreated, survival is similar to that of the general population. In critical PS, if there is no intervention, then it is a terminal presentation in the neonate. In PS requiring surgical intervention, the outcome is impacted by younger age at the point of intervention, a higher initial pressure gradient and a high residual gradient.