Ischaemic heart disease is becoming an increasingly frequent cause of ischaemic mitral regurgitation (IMR). Three different clinical entities of IMR, which deeply affect the clinical decision making, are distinguishable: the acute IMR complicating an acute myocardial infarction, the true IMR secondary to a transient ischaemic phenomenon, and the chronic functional IMR (FIMR). The incidence of the two first entities is low; the third is much more frequent.

ACUTE ISCHAEMIC MITRAL REGURGITATION COMPLICATING THE ACUTE PHASE OF MYOCARDIAL INFARCTION

IMR can occur acutely in patients sustaining an acute myocardial infarction. The rupture of a papillary muscle—most frequently a head of a posteromedial papillary muscle—is a dramatic mechanical complication of acute myocardial infarction, leading to a very high mortality rate in the absence of immediate surgical intervention. Surgery, most often valve replacement, is warranted after stabilisation of the haemodynamic status using an intra-aortic balloon pump and vasodilators.1 In the absence of such a rupture, the presence of IMR in the acute myocardial infarction phase portends a grave prognosis. Its incidence and clinical importance are largely underestimated, partly because physical examination is rather insensitive. Prompt in-hospital revascularisation can prevent or reverse acute IMR.2 When limited to the inferior wall, early revascularisation may reduce localised left ventricular (LV) remodelling and IMR.3 Early revascularisation also increases survival in patients with acute IMR presenting with shock.4

TRUE ISCHAEMIC MITRAL REGURGITATION

This second form truly defines IMR because it is secondary to an active ischaemic episode. It is clinically most often revealed by a “whistling angina“ or a “flash pulmonary oedema”.5 It is linked to the presence of a significant stenosis of the right or left circumflex coronary artery. In this situation, the primary treatment is to prevent the episodes of active myocardial ischaemia by a revascularisation procedure.

CHRONIC FUNCTIONAL ISCHAEMIC MITRAL REGURGITATION

Chronic FIMR, the most common cause of IMR, broadly denotes abnormal function of normal leaflets in the context of …