Pulmonary Valve Stenosis

Pulmonary valve stenosis is obstruction at the pulmonary valve causing right ventricular pressure overload.

Mostly congenital (7 to 10% of congenital heart disease): dysplastic or domed valve, Noonan syndrome (dysplastic valve), Williams syndrome (supravalvular), Alagille syndrome (peripheral), congenital rubella (peripheral).

Acquired: carcinoid heart disease, rheumatic (rare).

Severity by peak instantaneous Doppler gradient: mild under 36 mmHg (peak velocity under 3 m/s), moderate 36 to 64 mmHg, severe over 64 mmHg (velocity over 4 m/s).

Natural history: mild disease is stable; severe disease progresses to right ventricular hypertrophy, failure, and exertional syncope. Critical stenosis in neonates is duct dependent.

• Mild to moderate: asymptomatic, murmur found on routine examination.
• Dyspnoea, fatigue, exertional syncope or angina, right heart failure in severe disease.
• Neonates with critical stenosis: cyanosis (via patent foramen ovale shunt), duct dependent circulation.
• Harsh ejection systolic murmur at the left upper sternal border with thrill, ejection click that decreases with inspiration, soft or delayed P2, right ventricular heave, prominent a wave.
• Noonan features: hypertelorism, webbed neck, short stature, chest deformity.

• Echocardiography: valve morphology (domed or dysplastic), annulus size, Doppler gradient, right ventricular hypertrophy, tricuspid regurgitation, associated defects (atrial septal defect, patent foramen ovale).
• ECG: right axis deviation, right ventricular hypertrophy, tall R in V1.
• Chest radiograph: poststenotic pulmonary artery dilatation, normal vascularity.
• Cardiac MRI or CT for right ventricular function and peripheral pulmonary arteries.
• Catheterisation to measure gradients and perform valvuloplasty.
• Genetic testing for syndromic forms (PTPN11 for Noonan).

• Mild disease: observation, echo every 3 to 5 years.
• Intervention indications: symptomatic, or asymptomatic with peak gradient over 64 mmHg (or mean over 40) and right ventricular hypertension or dysfunction.
• Percutaneous balloon valvuloplasty is first line for typical domed valves (balloon to annulus ratio 1.2 to 1.4): gradient reduces by more than 50%, with success in about 90%. Results are less good with dysplastic valves.
• Surgical valvotomy, valve replacement or transannular patch for dysplastic valves or when valvuloplasty fails; right ventricular outflow tract resection for infundibular hypertrophy.
• Neonates: prostaglandin E1 infusion 0.01 to 0.05 micrograms/kg/min to maintain duct patency, then balloon valvuloplasty.
• Complications to follow: pulmonary regurgitation (usually benign), residual stenosis, recurrence.
• Infective endocarditis prevention with dental hygiene; prophylaxis only for prosthetic material or prior endocarditis.
• Pregnancy is usually well tolerated in mild to moderate stenosis; treat severe stenosis beforehand.