Pulmonary Valve Disease

The pulmonary valve normally has three cusps, and is responsible for regulating the flow of deoxygenated blood from the right ventricle to the lungs. Pulmonary valve disease is very uncommon and can be due either to stenosis or insufficiency. The majority of pulmonary valve problems occur as the result of congenital heart disease but the pulmonary valve may rarely be damaged as result of infection, e.g. infective endocarditis, or as a result of disease, e.g. carcinoid disease, Marfan's syndrome or pulmonary hypertension.

• Pulmonary valve disease is very rare.
• Congenital disease represents the majority of all pulmonary valve problems.

Presentation

• Pulmonary stenosis may be diagnosed in utero or shortly after birth. Critical pulmonary stenosis causes cyanosis and is potentially lethal in the neonate.¹
• Ultrasound images of the four chambers of the heart in utero may demonstrate isolated pulmonary stenosis due to an abnormally thickened or bicuspid valve, or pulmonary stenosis in association with other congenital anomalies, e.g. Fallot's tetralogy, Noonan's syndrome, or as a result of intrauterine infection with rubella.²
• In infancy the condition is usually diagnosed by auscultation of the heart and the presence of a murmur.

Symptoms

The symptoms of pulmonary stenosis will vary with the severity of the stenosis. Mild pulmonary stenosis may be asymptomatic.

• Shortness of breath
• Chest pain
• Fainting or exertional syncope
• Sudden death

Signs

• Soft pulmonary systolic murmurs are more easily heard with the patient lying down. They are often heard in healthy individuals and may be due to physiological changes associated with respiration.
• Ejection systolic murmur along left upper edge of sternum.
• Pulmonary ejection click.
• Delayed 2nd heart sound with severe stenosis.
• Parasternal thrill and heave.
• "A waves" in the JVP.

Investigations

• Echocardiography: will confirm the valve defect and measure the flow across the valve.
• ECG: may show right ventricular hypertrophy, right atrial hypertrophy and right axis deviation.
• Angiography: may be required in children with multiple cardiac abnormalities.
• Chest X-ray: may show prominent pulmonary artery, and possibly enlargement of the right atrium and ventricle.

Management

• Medical:
  • Initial treatment of critical pulmonary stenosis in a neonate includes general resuscitation and infusion of prostaglandin E1 to dilate the ductus arteriosus.
  • If the patient is asymptomatic, and the right ventricular pressure is less than 60 mmHg then the patient should be monitored every 1-2 years by a cardiologist who will perform ECG, and echocardiography and may perform chest x-ray and an exercise ECG.
  • All patients should be informed of the risk of endocarditis, and should be given prophylactic antibiotics prior to any dental or surgical procedure.³
• Surgical:
  • If the patient is symptomatic, and/or has a right ventricular pressure greater than 60 mmHg, balloon valvotomy is now the treatment of choice via cardiac catheterisation.⁴
  • Balloon valvotomy can result in a degree of pulmonary incompetence, and if this in time becomes severe, it may necessitate a pulmonary valve replacement.
  • Percutaneous pulmonary valve implantation is an alternative to surgical valve repair or replacement for right ventricular outflow tract dysfunction.⁵

Prognosis

• The prognosis will depend on the severity of the pulmonary stenosis, and any damage to the right ventricle and right atrium.

• Pulmonary regurgitation occurs only very rarely as a congenital anomaly.
• However it is a common complication after surgical or percutaneous relief of pulmonary stenosis and following repair of tetralogy of Fallot.⁴
• Pulmonary regurgitation may also occur secondary to a dilated pulmonary valve ring due to pulmonary hypertension or Marfan's disease.

Presentation

• Pulmonary regurgitation is usually asymptomatic unless severe, when it may lead to signs of right heart failure.
• Soft diastolic murmur at left upper sternal edge.
• Right ventricular hypertrophy.
• Loud P2 (pulmonary component of the second heart sound).
• May be differentiated from aortic regurgitation by lack of collapsing pulse.

Management

• Patients should be advised of the risk of endocarditis and given prophylactic antibiotics prior to any interventional procedure.
• Follow-up by a cardiologist every 1-3 years depending on severity and cause.
• If symptomatic or right ventricular dilatation, pulmonary valve replacement should be considered.
• If severe right heart failure and pulmonary hypertension, a heart-lung transplant may be required.

Prognosis

• Pulmonary regurgitation is usually well tolerated in childhood.
• Recent long-term studies have demonstrated that pulmonary regurgitation leads to progressive right ventricular dilatation, right ventricular dysfunction, exercise intolerance, ventricular tachycardia, and sudden cardiac death.⁶