Abnormalities seen in the great arteries view

Pulmonary valve stenosis with intact ventricular septum is a narrowing at the level of the valve. The pulmonary valve is thickened and it does not 'disappear' in systole. Colour Doppler demonstrates turbulent flow throughout the arterial duct and PW Doppler accross the valve demonstrates increased flow velocity (≥100 cm/sec in the second trimester). The severity of pulmonary stenosis varies from mild to severe. This is an evolving lesion and can progress during pregnancy to more severe stenosis or to complete atresia of the pulmonary valve.

In cases where pulmonary artery stenosis is either mild or moderate, the right ventricle may appear normal. However, if pulmonary stenosis is severe there may be hypertrophy of the right ventricle and tricuspid valve regurgitation. Decreased right ventricular function can be observed in some cases.

Prevalence

Pulmonary stenosis with intact ventricular septum is found in about 6 in 100,000 live births.

Other abnormalities

Pulmonary stenosis with intact ventricular septum is associated with genetic conditions, such as Noonan syndrome or Williams syndrome.

Prognosis

In mild and moderate pulmonary stenosis the management is conservative. In severe pulmonary stenosis with preserved right ventricular function, the treatment of choice is balloon valvuloplasty with good long-term outcome. In severe pulmonary stenosis or atresia with right ventricular hypertrophy and impaired function, staged operations to one ventricle (Fontan circulation) is usually necessary and life expectancy is curtailed.

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