Pulmonary Valve Stenosis

Essentials of Diagnosis

• High-pitched systolic ejection murmur maximal in the second left interspace with radiation to the left shoulder

• P₂ delayed and soft or absent

• Pulmonary ejection click often present and decreases with inspiration—the only right heart sound that decreases with inspiration; all other right heart sounds increase

• Echocardiography/Doppler is diagnostic

• Patients with peak pulmonic valve gradient > 64 mm Hg or a mean of 35 mm Hg by echocardiography/Doppler should undergo intervention regardless of symptoms; otherwise, percutaneous or surgical intervention may be indicated for symptoms or evidence of right ventricular (RV) dysfunction

General Considerations

• Often congenital and associated with other cardiac lesions

• In valvular pulmonic stenosis, pulmonary blood flow preferentially goes to the left lung

• Most patients with valvular pulmonic stenosis have a domed valve, although some patients have a dysplastic valve

• Peripheral pulmonic stenosis

  • Can accompany valvular pulmonic stenosis

  • May be part of a variety of clinical syndromes, including the congenital rubella syndrome

• Noncongenital postoperative pulmonic valvular or main pulmonary artery (PA) stenosis

  • May be seen in patients who have had the Ross procedure for aortic valve disease

  • Occurs due to an immune response in the homograft

• RV outflow obstructions can also occur when there is

  • A conduit from the RV to the pulmonary artery that becomes stenotic from degenerative changes over time

  • Degeneration of a bioprosthetic replacement pulmonary valve

• Mild cases of pulmonic stenosis are asymptomatic

• Moderate to severe pulmonic stenosis may cause

  • Dyspnea on exertion

  • Syncope

  • Chest pain

  • RV failure

• In mild to moderate pulmonic stenosis

  • A loud ejection click can be heard to precede the murmur

  • This sound decreases with inspiration as the increased RV filling from inspiration prematurely opens the valve during atrial systole when inspiratory increased blood flow to the right heart occurs

• In severe pulmonic stenosis

  • The second sound is obscured by the murmur

  • Pulmonary component of S₂ may be diminished, delayed, or absent

  • A right-sided S₄ and a prominent a wave in the venous pulse are present when there is RV diastolic dysfunction or a c-v wave may be observed in the jugular venous pressure if tricuspid regurgitation is present

• Stenosis of the pulmonary valve or RV infundibulum increases the resistance to RV outflow, raises the RV pressure, and limits pulmonary blood flow

Imaging

• Radiography

  • Heart size may be normal

  • A prominent RV and RA or gross cardiac enlargement may be present, depending on the severity

• Echocardiography/Doppler

  • Diagnostic

  • Can provide evidence for a doming valve versus a dysplastic valve

  • Can estimate the gradient across the valve

  • Peak gradients

    • Mild pulmonic stenosis: < 36 mm Hg

    • Moderate pulmonic stenosis: 36–64 mm Hg

    • Severe pulmonic stenosis: > 64 mm Hg (or mean gradient > 35 mm Hg)

• MRI and CT do not add additional information unless there is concern regarding associated cardiac lesions or peripheral pulmonary arterial lesions

Diagnostic Studies

• ECG

  • Right axis deviation or RVH is noted

  • Peaked P waves provide evidence of right atrial (RA) overload

• Catheterization

  • Usually unnecessary for the diagnosis

  • Should be used only if the data are unclear or in preparation for either percutaneous intervention or surgery

• Class I (definitive) indications for intervention

  • All symptomatic patients

  • All patients with a resting peak-to-peak gradient > 64 mm Hg or a mean gradient > 35 mm Hg, regardless of symptoms

• Percutaneous balloon valvuloplasty is treatment of choice for domed pulmonary valve stenosis

• Surgical commissurotomy can be done when pulmonary valve regurgitation is too severe or the valve is dysplastic

• Percutaneous pulmonary valve replacement

  • Both the Medtronic Melody valve and the Edwards Sapien XT valve are FDA approved

  • Relieves pulmonary outflow tract obstruction due to RV to PA conduit stenosis or following the Ross procedure or due to homograft pulmonary valve stenosis

  • Have also been performed off-label for patients with native pulmonary valve disease, including those who have had tetralogy of Fallot repair (assuming the PA root size is small enough to seat a percutaneous valve)

Follow-Up

• The degree of stenosis worsens with time in a few patients, so serial follow-up is important

Prognosis

• Mild pulmonic stenosis: Patients have a normal life span with no intervention

• Moderate stenosis

  • May be asymptomatic in childhood and adolescence

  • Symptoms often appear as patients grow older

• Severe stenosis

  • Rarely associated with sudden death

  • Can cause right heart failure in patients as early as in their 20s and 30s

• Pregnancy and exercise tend to be well tolerated except in severe stenosis

When to Refer

• All symptomatic patients (regardless of gradient)

• All asymptomatic patients whose peak pulmonary valve gradient is > 64 mm Hg or whose mean gradient is > 35 mm Hg should be referred to a cardiologist with expertise in adult congenital heart disease