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Key Features

Essentials of Diagnosis

  • No symptoms in mild or moderate stenosis

  • Cyanosis and a high incidence of right-sided heart failure (HF) in ductal-dependent lesions

  • Right ventricular (RV) lift with systolic ejection click heard at the third left intercostal space

  • S2 widely split with soft to inaudible P2; grade I–VI/VI systolic ejection murmur, maximal at the pulmonary area

  • Dilated pulmonary artery on chest radiograph

General Considerations

  • Accounts for 10% of all congenital heart disease

  • The pulmonary valve annulus is usually small with moderate to marked poststenotic dilation of the main pulmonary artery

  • Obstruction to blood flow across the pulmonary valve causes an increase in RV pressure

  • Pressures greater than systemic are potentially life-threatening and are associated with critical obstruction

  • Because of the increased RV strain, severe right ventricular hypertrophy (RVH) and eventual RV failure can occur

  • When obstruction is severe and the ventricular septum is intact, a right-to-left shunt often occurs at the atrial level through a patent foramen ovale (PFO)

  • In neonates with severe obstruction and minimal antegrade pulmonary blood flow (critical PS),

    • Left-to-right flow through the ductus is essential

    • Prostaglandin is a necessary intervention at the time of birth

    • Infants are cyanotic at presentation

Clinical Findings

  • Mild to moderate obstruction

    • Patients are

      • Acyanotic and asymptomatic

      • Well developed and well nourished

      • Not prone to pulmonary infections

    • Pulses are normal

    • Precordium may be prominent, often with palpable RV heave

    • A systolic thrill is often present in the pulmonary area

    • Prominent ejection click of pulmonary origin

      • Heard at the third left intercostal space

      • Varies with respiration, being more prominent during expiration than inspiration

  • Severe obstruction

    • Cyanosis may develop early

    • Click tends to merge with S1

  • S2 varies with the degree of stenosis

    • Normal in mild pulmonic stenosis

    • More widely split and the pulmonary component is softer in moderate pulmonic stenosis

    • Single because the pulmonary component cannot be heard in severe pulmonary stenosis

  • Rough systolic ejection murmur

    • Best heard at the second left interspace

    • Radiates well to the back

    • Usually short in severe pulmonary valve obstruction

  • No diastolic murmurs are audible



  • Radiography

    • Heart size is normal

    • Poststenotic dilation of the main pulmonary artery and the left pulmonary artery often occurs

  • Echocardiography

    • Confirms the diagnosis

    • Defines the anatomy

    • Identifies any associated lesions

    • Pulmonary valve has thickened leaflets with reduced valve leaflet excursion

    • Transvalvular pressure gradient can be estimated accurately by Doppler, which

      • Provides an estimate of RV pressure

      • Can assist in determining the appropriate time to intervene

Diagnostic Procedures

  • Electrocardiography

    • Usually normal with mild obstruction

    • Right axis deviation occurs in moderate to severe stenosis

    • In severe obstruction

      • RVH with an RV strain pattern (deep inversion of the T wave) occurs in the right precordial leads (V3R, V1, V2)


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