Mitral valve disease

Mitral stenosis (MS) has become less common in developed countries following the declining incidence of rheumatic fever but remains a major health problem worldwide. The main symptom is breathlessness and its onset may be insidious. Atrial fibrillation is common and may trigger the onset of pulmonary oedema. Medical treatment is aimed at control of atrial fibrillation and prevention of thromboembolism. Patients with symptoms and a valve area <1.5 cm2 should be considered for intervention by means of balloon valvuloplasty or surgical valve replacement. Mitral regurgitation (MR) is common and most often caused by degenerative disease of the valve itself, or secondary to ischaemic heart disease affecting the underlying myocardium and preventing normal leaflet closure. Management depends upon the aetiology. Patients with severe degenerative MR should be offered valve repair before the onset of limiting symptoms or left ventricular dysfunction. Surgery for ischaemic MR is less successful, but should be considered in patients with moderate or severe MR undergoing coronary artery bypass grafting and in patients with severe MR and symptoms of breathlessness. Percutaneous approaches are an emerging alternative in some patients.