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Quantitation of mitral regurgitation: rationale, approach, and interpretation in clinical practice

Quantitation of mitral regurgitation has made considerable progress is recent years, providing unique insights into the physiology of the condition, and providing essential tools for a proactive modern management of patients with MR

Mitral regurgitation (MR) is a valvar haemodynamic alteration which is the focus of intense interest despite the decline of rheumatic disease, because of its high frequency.1 Indeed, in our current aging population, MR is most often caused by diseases prevalent in the elderly, either degenerative lesions (such as mitral valve prolapse or ruptured chordae) or functional alterations (the consequence of ventricular dysfunction).2 Hence, the assessment of MR is a key task of internists, cardiologists, and cardiac surgeons and has been transformed by Doppler echocardiography. In the past decade new methods and new concepts have been developed for the quantitation of MR, which have been detailed by Irvine and colleagues in this supplement to Heart .3 As one may ponder the incremental benefit of new approaches, it is important to review their rationale, to delineate how to integrate them in a global approach, and how to interpret these new results.

### Rationale 1: MR impacts seriously on outcome

Severe MR has the reputation of being well tolerated for many years. Although this is occasionally true, this dogma has little support from outcome data. Indeed, when we examined the long term outcome of patients with flail leaflets that epitomise severe MR,4 excess mortality,5 and high morbidity6,7 were observed, with high rates of heart failure, atrial fibrillation,7 and even sudden death.6 It is also remarkable that in functional MR, although the disease is not initially valvar in nature, the higher the degree of MR, the worse the …