Ischaemic mitral regurgitation

There are still controversies regarding the mechanisms and optimal treatment of ischaemic mitral regurgitation. Coronary heart disease is the third most important cause of mitral regurgitation (10%), after myxomatous degeneration (45%), and rheumatic heart disease (40%). Ischaemic mitral regurgitation is a strong adverse risk factor, and it is more common in patients with triple vessel disease. Recent experimental and echocardiographic studies have shown that changes in the shape of the left ventricle, the development of akinetic segments, and asymmetrical mitral annular dilatation are the most important mechanisms. There is no evidence to support the concept of papillary muscle dysfunction as a clinical cause of mitral regurgitation. Dynamic mitral regurgitation may be the cause of dyspnoea as the predominant symptom in a patient with myocardial ischaemia. Regurgitation occurs when there is asymmetrical apposition of the mitral valve leaflets, and/or loss of coaptation. Echocardiography is the investigation of choice for identifying the mechanisms and severity of mitral regurgitation, and for planning optimal treatment.