Mitral stenosis and pregnancy

Mitral stenosis is predominantly due to prior rheumatic fever.
Stenotic vulvular lesions are less well tolerated in pregnancy with maternal mortality rate greater than 10%.
Poor prognostic signs are presence of symptoms pre-pregnancy and severe stenosis (valve area <1 cm2).
Patients usually present with breathlessness, fatigue or acute pulmonary oedema.
Due to dilatation of the left atrium, they often have atrial fibrillation. Tapping apex beat, loud first heart sound and mid diastolic murmur are features of mitral stenosis.
Patients with atrial dilatation may require prophylactic heparin and those with atrial dilatation require therapeutic heparin.